Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S has 238mi range @65mph

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Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S has 238mi range @65mph

Jukka Järvinen-3
I've been told that the ground effect for F1 is merely a safety
factor. At those speeds vehicles "take off" if there is air under the
wings. Also they are looking for downforce not efficiency.

I could feel the car becoming more flimsy on the high setup but at the
same time the Watts taken from batteries drop. Unfortunately I have
dismantled the vehicle, rebuilt it and sold it away.

Currently the shoemaker do not have shoes (which is sad). So I cannot
go out for a spinn.

But from what I've learned about aerodynamics the negative pressure is
the force which pulls the planes up in the air. This same negative
pressure is in the rear of the vehicle. And it "pulls" the car
backwards if you go fast enough. The positive pressure in the front is
not that significant.

The same aerodynamic forces are in the same way forcing the perfectly
round drop of water in free fall to take the tear shape. More force
more drastic change in the shape.

More frontal area, more air is "compressed" in the front to go by the
car. Just to be released back to the negative pressure field. At
certain point the air flow goes from laminar flow to turbulent. And it
adds again to the resistive forces.

So.. If you allow more air go under the car It'll stay laminar near to
the ground but the uneven bottom parts of the vehicle will stir the
flow. This is why we wish to have smooth belly pan. But.. even the
stirring is added it still resists less the vehicle movement due the
more equal air flow around the car. It moves the negative pressure
point closer to the middle of the trunk and allows more air to pass in
laminar flow.

I saw this effect already in 2005 while driving a lot on highways. I
had an opportunity to drive bulky EV with 100 mile range and highly
accurate measurement devices as full time job for years. (not just
driving but trying to find ways to prevent LCP-afterburners)

I know there has been a lot of threads in here about the aerodynamics
during past 20 years. So let's get this summarized again so we do not
need to dig out our mid 1990's laptops. :P

-Jukka

http://www.google.com/profiles/jarviju#about


2012/9/12 Martin WINLOW <[hidden email]>:

> Well, less frontal area (less tyre frontal area) for starters and I'm sure there is a separate aerodynamic factor at playas well to do with the venturi effect... made less detrimental to efficiency with a smaller air gap - which is one reason why F1 cars ride so low...
>
> MW
>
>
> On 12 Sep 2012, at 13:37, Jukka Järvinen wrote:
>
>> Suspension set to the lowest setting. Why ?
>>
>> I've noticed that setting it high adds efficiency. (Brusa made Wh
>> meter was used)
>>
>> So Model-S in this case could have been more efficient by doing that.
>>
>> My conclusion was that more air passes underneath the vehicle and
>> lessens the negative pressure in the rear.
>>
>> Can anyone else in here concur ?
>>
>> -akkuJukka
>>
>>
>> http://www.google.com/profiles/jarviju#about
>>
>>
>> 2012/9/12 brucedp5 <[hidden email]>:
>>>
>>> The Tesla-S is still the electric range king
>>>
>>> http://www.plugincars.com/whats-real-world-range-tesla-model-s-124318.html
>>> [image] What's the Real-World Range of the Tesla Model S?
>>> By Eric Loveday  Sep 10 2012
>>>
>>> [image] Tesla Model S
>>> Tesla's spectacular Model S electric sedan grabs headlines on a daily basis,
>>> but the key metric for an electric vehicle is its real-world range. Until
>>> recently, we could only post Tesla's estimated range rating of 265 miles for
>>> the 85-kWh version of the Model S, but now there's been some real-world
>>> testing, conducted by Motor Trend, which proves that Tesla wasn't off the
>>> mark by much.
>>>
>>> Recently, the folks at Motor Trend took a Model S for an extended road trip.
>>> After a mixed driving test from El Segundo, Calif. to San Diego and back,
>>> the staff at Motor Trend discovered that the Model S is easily capable of
>>> covering 238 miles on a full charge.
>>>
>>> Motor Trend posted this after completing its lengthy test drive in the Tesla
>>> Model S: "The total range—adding the unused 4 miles—would be 238. Yes, 238
>>> is 11 percent short of 265. Moreover, it was done while being very stingy
>>> with performance (for the most part). Is that 265 actually valid? If you
>>> drive predominately at highway speeds, then probably not. But were we to
>>> have included more medium-speed roads (long stretches at 45-50 miles per
>>> hour) well, possibly."
>>>
>>> Motor Trend operated the Model S with the A/C in the off position, but had
>>> the vehicle's ventilation system turned on. Cruise control was set at 65 mph
>>> and the crew set the Model S' air suspension to its lowest setting.
>>>
>>> At 238 miles, the efficiency of the Model S, with its 85 kWh battery pack,
>>> is 2.8 miles per kilowatt hour. That's not very efficient for a small
>>> electric car like the Nissan LEAF or Honda Fit EV, but the Model S is a
>>> significantly larger vehicle. While the Model S is breaking new
>>> technological ground in many ways, these numbers do not indicate a
>>> revolutionary change in efficiency.
>>>
>>> But in the end, the Model S still managed to return more range than any
>>> other mass produced electric vehicle ever tested by a major publication. So,
>>> whether it's 238 or 265 miles, the 85-kWh version of the Tesla Model S is,
>>> as of right now, the electric range king.
>>> [© 2012 PluginCars.com ]
>
>
>
>
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Re: Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S has 238mi range @65mph

Evan Tuer
On Wed, Sep 12, 2012 at 5:20 PM, Jukka Järvinen <[hidden email]> wrote:

> But from what I've learned about aerodynamics the negative pressure is
> the force which pulls the planes up in the air.

Off-topic maybe but I don't think that's correct :)

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Re: Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S has 238mi range @65mph

Cor van de Water
It is *exactly* correct.
That is why the *top* of Airplane wings is curved,
so the low pressure appears at the upper side of the wing,
pulling the wing upward and keeping the plane in the air.

Cor van de Water
Chief Scientist
Proxim Wireless Corporation http://www.proxim.com
Email: [hidden email] Private: http://www.cvandewater.com
Skype: cor_van_de_water Tel: +1 408 383 7626


-----Original Message-----
From: [hidden email] [mailto:[hidden email]] On Behalf Of Evan Tuer
Sent: Wednesday, September 12, 2012 9:27 AM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S has 238mi range @65mph

On Wed, Sep 12, 2012 at 5:20 PM, Jukka Järvinen <[hidden email]> wrote:

> But from what I've learned about aerodynamics the negative pressure is
> the force which pulls the planes up in the air.

Off-topic maybe but I don't think that's correct :)

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Re: Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S has 238mi range @65mph

Evan Tuer
Cor, so you're telling me that negative pressure due to airflow over
the aerofoil section of the wing is the only thing that makes an
aeroplane fly?


On Wed, Sep 12, 2012 at 5:54 PM, Cor van de Water <[hidden email]> wrote:

> It is *exactly* correct.
> That is why the *top* of Airplane wings is curved,
> so the low pressure appears at the upper side of the wing,
> pulling the wing upward and keeping the plane in the air.
>
> Cor van de Water
> Chief Scientist
> Proxim Wireless Corporation http://www.proxim.com
> Email: [hidden email] Private: http://www.cvandewater.com
> Skype: cor_van_de_water Tel: +1 408 383 7626
>
>
> -----Original Message-----
> From: [hidden email] [mailto:[hidden email]] On Behalf Of Evan Tuer
> Sent: Wednesday, September 12, 2012 9:27 AM
> To: Electric Vehicle Discussion List
> Subject: Re: [EVDL] Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S has 238mi range @65mph
>
> On Wed, Sep 12, 2012 at 5:20 PM, Jukka Järvinen <[hidden email]> wrote:
>
>> But from what I've learned about aerodynamics the negative pressure is
>> the force which pulls the planes up in the air.
>
> Off-topic maybe but I don't think that's correct :)
>
> _______________________________________________
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Re: Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S has 238mi range @65mph

Cor van de Water
Evan,
It is not the *only* force that acts on a wing, there are two main
effects that create "lift" on an airplane wing - the airfoil and the
angle of attack. Otherwise a plane would be unable to fly upside down
as you see in some fighter plane demonstrations, although they need
to take care to fly within much tighter parameters when flying upside
down, since the airfoil is actually working in the wrong direction,
so the pilot must compensate by creating a much larger angle of attack
to create enough lift to keep the plane in the air *and* counter-act
the negative lift of the airfoil.
Of course all this is also impacted by the adjustment of the flaps
on the wings - that is why at deliberate low speed flying (during
take-off and landing) the airfoil is enlarged by shifting flaps out of
the wing and creating larger drag by increasing the airfoil and thus
the pressure difference.

You can read up on the aerodynamics of airplane wings at Wikipedia:
http://en.wikipedia.org/wiki/Lift_%28force%29

Cor van de Water
Chief Scientist
Proxim Wireless Corporation http://www.proxim.com
Email: [hidden email] Private: http://www.cvandewater.com
Skype: cor_van_de_water Tel: +1 408 383 7626


-----Original Message-----
From: [hidden email] [mailto:[hidden email]] On Behalf Of Evan Tuer
Sent: Wednesday, September 12, 2012 10:01 AM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S has 238mi range @65mph

Cor, so you're telling me that negative pressure due to airflow over
the aerofoil section of the wing is the only thing that makes an
aeroplane fly?


On Wed, Sep 12, 2012 at 5:54 PM, Cor van de Water <[hidden email]> wrote:

> It is *exactly* correct.
> That is why the *top* of Airplane wings is curved,
> so the low pressure appears at the upper side of the wing,
> pulling the wing upward and keeping the plane in the air.
>
> Cor van de Water
> Chief Scientist
> Proxim Wireless Corporation http://www.proxim.com
> Email: [hidden email] Private: http://www.cvandewater.com
> Skype: cor_van_de_water Tel: +1 408 383 7626
>
>
> -----Original Message-----
> From: [hidden email] [mailto:[hidden email]] On Behalf Of Evan Tuer
> Sent: Wednesday, September 12, 2012 9:27 AM
> To: Electric Vehicle Discussion List
> Subject: Re: [EVDL] Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S has 238mi range @65mph
>
> On Wed, Sep 12, 2012 at 5:20 PM, Jukka Järvinen <[hidden email]> wrote:
>
>> But from what I've learned about aerodynamics the negative pressure is
>> the force which pulls the planes up in the air.
>
> Off-topic maybe but I don't think that's correct :)
>
> _______________________________________________
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Re: Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S has 238mi range @65mph

Roger Stockton
In reply to this post by Evan Tuer
Evan Tuer wrote:

> Cor, so you're telling me that negative pressure due to airflow over
> the aerofoil section of the wing is the only thing that makes an
> aeroplane fly?

It is certainly the mechanism that generates the lift that allows the airplane to fly.

I suppose it is arguable whether it is the negative pressure on the top side of the airfoil that "pulls up" on it or the positive pressure on the lower side of the airfoil that "pushes up" on it, and I suspect the relative contributions of the two vary depending upon the specific airfoil profile.  Probably the easiest thing to agree in general is that it is the difference in pressure above and below the airfoil that generates lift.

Cheers,

Roger.


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Re: Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S has 238mi range @65mph

Evan Tuer
In reply to this post by Cor van de Water
On Wed, Sep 12, 2012 at 6:21 PM, Cor van de Water <[hidden email]> wrote:
> Evan,
> It is not the *only* force that acts on a wing, there are two main
> effects that create "lift" on an airplane wing - the airfoil and the
> angle of attack. Otherwise a plane would be unable to fly upside down

Exactly!   I was only querying the preceding statement because it
seemed to imply that it was "the" force rather than the lesser of
those two effects, and that's not "totally" correct, if we are
discussing the basics.

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Re: Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S has 238mi range @65mph

Jukka Järvinen-3
In reply to this post by Roger Stockton
While it might look like we're getting off topic I'm certain this
debate will educate us how to make more streamlined vehicles.

Most aeromoded vehicles look a bit dumb and abnormal. You've seen them
so you know what I'm talking about. They look far from "normal".

I hope Tesla did great and they were able to do things out of the box.
No traditional engine compartments and flat bottom.

But 2,8 mi/kWh (223Wh/km) ? That was from the vehicle computer and
from batteries ? Does not tell that much about anything unless we know
the rest of the facts (raw data would be fantastic).

-akkuJukka

http://www.google.com/profiles/jarviju#about


2012/9/12 Roger Stockton <[hidden email]>:

> Evan Tuer wrote:
>
>> Cor, so you're telling me that negative pressure due to airflow over
>> the aerofoil section of the wing is the only thing that makes an
>> aeroplane fly?
>
> It is certainly the mechanism that generates the lift that allows the airplane to fly.
>
> I suppose it is arguable whether it is the negative pressure on the top side of the airfoil that "pulls up" on it or the positive pressure on the lower side of the airfoil that "pushes up" on it, and I suspect the relative contributions of the two vary depending upon the specific airfoil profile.  Probably the easiest thing to agree in general is that it is the difference in pressure above and below the airfoil that generates lift.
>
> Cheers,
>
> Roger.
>
>
> _______________________________________________
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Re: Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S has 238mi range @65mph

Dennis Miles
In reply to this post by Jukka Järvinen-3
Akkujukka, Today must be the day to comment on your comments.  You
said,"The same aerodynamic forces are in the same way forcing the
perfectly round drop of water in free fall to take the tear shape."(This is
related to understanding streamlining of any EV.) The perfectly round drop
of water in free space without air movement passing by it is round due to
the surface tension Just like a simple balloon. But in moving air such as
falling thru the atmosphere, the droplet takes on a shape similar to a
chicken egg, not exactly round but elongated and not a teardrop. the
teardrop comes when the droplet is in contact with a surface such as a
lady's cheek or a window pane because the surface contacting the drop
elongates by the adhesion to the surface holding it back and the drop
elongates into a teardrop shape. Take a hard boiled egg, lay it on its side
and pass it thru a knife lying with the blade parallel with the flat
surface removing about 1/3 of the egg, the part left larger end to the
front is more streamlined. Look at a picture of a modern nuclear submarine
view the Bow (Front) and Stern (Back) shapes, (the middle is like a simple
pipe so ignore that), but the submarine moves thru water (Much more viscus
than air) and learn streamlining from it, Notice no long pointy front, and
not a blunt tail, Billions of dollars in research went into the shape of a
submarine.
Regards,
*     Dennis *(EVprofessor)* Miles*
  *(863)944-9913* (phone noon to midnight E.S.T.)
*    reply to [hidden email]*
+++++++++++++++++++++++++++++++++++++++++
On Wed, Sep 12, 2012 at 12:20 PM, Jukka Järvinen <[hidden email]>wrote:

> I've been told that the ground effect for F1 is merely a safety
> factor. At those speeds vehicles "take off" if there is air under the
> wings. Also they are looking for downforce not efficiency.
>
> I could feel the car becoming more flimsy on the high setup but at the
> same time the Watts taken from batteries drop. Unfortunately I have
> dismantled the vehicle, rebuilt it and sold it away.
>
> Currently the shoemaker do not have shoes (which is sad). So I cannot
> go out for a spinn.
>
> But from what I've learned about aerodynamics the negative pressure is
> the force which pulls the planes up in the air. This same negative
> pressure is in the rear of the vehicle. And it "pulls" the car
> backwards if you go fast enough. The positive pressure in the front is
> not that significant.
>
> The same aerodynamic forces are in the same way forcing the perfectly
> round drop of water in free fall to take the tear shape. More force
> more drastic change in the shape.
>
> More frontal area, more air is "compressed" in the front to go by the
> car. Just to be released back to the negative pressure field. At
> certain point the air flow goes from laminar flow to turbulent. And it
> adds again to the resistive forces.
>
> So.. If you allow more air go under the car It'll stay laminar near to
> the ground but the uneven bottom parts of the vehicle will stir the
> flow. This is why we wish to have smooth belly pan. But.. even the
> stirring is added it still resists less the vehicle movement due the
> more equal air flow around the car. It moves the negative pressure
> point closer to the middle of the trunk and allows more air to pass in
> laminar flow.
>
> I saw this effect already in 2005 while driving a lot on highways. I
> had an opportunity to drive bulky EV with 100 mile range and highly
> accurate measurement devices as full time job for years. (not just
> driving but trying to find ways to prevent LCP-afterburners)
>
> I know there has been a lot of threads in here about the aerodynamics
> during past 20 years. So let's get this summarized again so we do not
> need to dig out our mid 1990's laptops. :P
>
> -Jukka
>
> http://www.google.com/profiles/jarviju#about
>
>
> 2012/9/12 Martin WINLOW <[hidden email]>:
> > Well, less frontal area (less tyre frontal area) for starters and I'm
> sure there is a separate aerodynamic factor at playas well to do with the
> venturi effect... made less detrimental to efficiency with a smaller air
> gap - which is one reason why F1 cars ride so low...
> >
> > MW
> >
> >
> > On 12 Sep 2012, at 13:37, Jukka Järvinen wrote:
> >
> >> Suspension set to the lowest setting. Why ?
> >>
> >> I've noticed that setting it high adds efficiency. (Brusa made Wh
> >> meter was used)
> >>
> >> So Model-S in this case could have been more efficient by doing that.
> >>
> >> My conclusion was that more air passes underneath the vehicle and
> >> lessens the negative pressure in the rear.
> >>
> >> Can anyone else in here concur ?
> >>
> >> -akkuJukka
> >>
> >>
> >> http://www.google.com/profiles/jarviju#about
> >>
> >>
> >> 2012/9/12 brucedp5 <[hidden email]>:
> >>>
> >>> The Tesla-S is still the electric range king
> >>>
> >>>
> http://www.plugincars.com/whats-real-world-range-tesla-model-s-124318.html
> >>> [image] What's the Real-World Range of the Tesla Model S?
> >>> By Eric Loveday  Sep 10 2012
> >>>
> >>> [image] Tesla Model S
> >>> Tesla's spectacular Model S electric sedan grabs headlines on a daily
> basis,
> >>> but the key metric for an electric vehicle is its real-world range.
> Until
> >>> recently, we could only post Tesla's estimated range rating of 265
> miles for
> >>> the 85-kWh version of the Model S, but now there's been some real-world
> >>> testing, conducted by Motor Trend, which proves that Tesla wasn't off
> the
> >>> mark by much.
> >>>
> >>> Recently, the folks at Motor Trend took a Model S for an extended road
> trip.
> >>> After a mixed driving test from El Segundo, Calif. to San Diego and
> back,
> >>> the staff at Motor Trend discovered that the Model S is easily capable
> of
> >>> covering 238 miles on a full charge.
> >>>
> >>> Motor Trend posted this after completing its lengthy test drive in the
> Tesla
> >>> Model S: "The total range—adding the unused 4 miles—would be 238. Yes,
> 238
> >>> is 11 percent short of 265. Moreover, it was done while being very
> stingy
> >>> with performance (for the most part). Is that 265 actually valid? If
> you
> >>> drive predominately at highway speeds, then probably not. But were we
> to
> >>> have included more medium-speed roads (long stretches at 45-50 miles
> per
> >>> hour) well, possibly."
> >>>
> >>> Motor Trend operated the Model S with the A/C in the off position, but
> had
> >>> the vehicle's ventilation system turned on. Cruise control was set at
> 65 mph
> >>> and the crew set the Model S' air suspension to its lowest setting.
> >>>
> >>> At 238 miles, the efficiency of the Model S, with its 85 kWh battery
> pack,
> >>> is 2.8 miles per kilowatt hour. That's not very efficient for a small
> >>> electric car like the Nissan LEAF or Honda Fit EV, but the Model S is a
> >>> significantly larger vehicle. While the Model S is breaking new
> >>> technological ground in many ways, these numbers do not indicate a
> >>> revolutionary change in efficiency.
> >>>
> >>> But in the end, the Model S still managed to return more range than any
> >>> other mass produced electric vehicle ever tested by a major
> publication. So,
> >>> whether it's 238 or 265 miles, the 85-kWh version of the Tesla Model S
> is,
> >>> as of right now, the electric range king.
> >>> [© 2012 PluginCars.com ]
> >
> >
> >
> >
> > -------------- next part --------------
> > An HTML attachment was scrubbed...
> > URL:
> http://lists.sjsu.edu/mailman/private/ev/attachments/20120912/a35cb876/attachment.html
> > _______________________________________________
> > | Moratorium on drag racing discussion is in effect.
> > | Please take those discussions elsewhere.  Thanks.
> > |
> > | REPLYING: address your message to [hidden email] only.
> > | Multiple-address or CCed messages may be rejected.
> > | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
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>
> _______________________________________________
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> | Please take those discussions elsewhere.  Thanks.
> |
> | REPLYING: address your message to [hidden email] only.
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|
| REPLYING: address your message to [hidden email] only.
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Re: Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S has 238mi range @65mph

Jukka Järvinen-3
I can see how the teardrops tail is very sharp due the surface tension
of the liquid while moving ahead on a surface. It's another effect
there. Drop of liquid is rounder while flying through air.

What it comes to submarines I can also see how they made a compromise
between frictions and maneuverability. Very sharp head and tail would
be optimal as they do on ocean liners (while they have the "torpedo"
which they sit on). But most of this is debatable.

How accurate measurement is available from Model-S ? So if one would
drive certain route through several times on different suspension
settings. We might be able to determine something. Would be good to
get most of the variables in the same region (SOC, air temp, humidity,
etc..)

Wind tunnel question. How do the engineers take in count the air
molecule inertia ? When shooting off the molecules they have different
state of tied in energy compared to molecule standing still while
vehicle rams to it. I'm sorry if I seem to be ignorant and showing off
my stupidity in various fields of physics. But somehow I feel this
still being on topic. :)

I've learned also more I know I know I do not know.

-akkuJukka
http://www.google.com/profiles/jarviju#about


2012/9/13 Dennis Miles <[hidden email]>:

> Akkujukka, Today must be the day to comment on your comments.  You
> said,"The same aerodynamic forces are in the same way forcing the
> perfectly round drop of water in free fall to take the tear shape."(This is
> related to understanding streamlining of any EV.) The perfectly round drop
> of water in free space without air movement passing by it is round due to
> the surface tension Just like a simple balloon. But in moving air such as
> falling thru the atmosphere, the droplet takes on a shape similar to a
> chicken egg, not exactly round but elongated and not a teardrop. the
> teardrop comes when the droplet is in contact with a surface such as a
> lady's cheek or a window pane because the surface contacting the drop
> elongates by the adhesion to the surface holding it back and the drop
> elongates into a teardrop shape. Take a hard boiled egg, lay it on its side
> and pass it thru a knife lying with the blade parallel with the flat
> surface removing about 1/3 of the egg, the part left larger end to the
> front is more streamlined. Look at a picture of a modern nuclear submarine
> view the Bow (Front) and Stern (Back) shapes, (the middle is like a simple
> pipe so ignore that), but the submarine moves thru water (Much more viscus
> than air) and learn streamlining from it, Notice no long pointy front, and
> not a blunt tail, Billions of dollars in research went into the shape of a
> submarine.
> Regards,
> *     Dennis *(EVprofessor)* Miles*
>   *(863)944-9913* (phone noon to midnight E.S.T.)
> *    reply to [hidden email]*
> +++++++++++++++++++++++++++++++++++++++++
> On Wed, Sep 12, 2012 at 12:20 PM, Jukka Järvinen <[hidden email]>wrote:
>
>> I've been told that the ground effect for F1 is merely a safety
>> factor. At those speeds vehicles "take off" if there is air under the
>> wings. Also they are looking for downforce not efficiency.
>>
>> I could feel the car becoming more flimsy on the high setup but at the
>> same time the Watts taken from batteries drop. Unfortunately I have
>> dismantled the vehicle, rebuilt it and sold it away.
>>
>> Currently the shoemaker do not have shoes (which is sad). So I cannot
>> go out for a spinn.
>>
>> But from what I've learned about aerodynamics the negative pressure is
>> the force which pulls the planes up in the air. This same negative
>> pressure is in the rear of the vehicle. And it "pulls" the car
>> backwards if you go fast enough. The positive pressure in the front is
>> not that significant.
>>
>> The same aerodynamic forces are in the same way forcing the perfectly
>> round drop of water in free fall to take the tear shape. More force
>> more drastic change in the shape.
>>
>> More frontal area, more air is "compressed" in the front to go by the
>> car. Just to be released back to the negative pressure field. At
>> certain point the air flow goes from laminar flow to turbulent. And it
>> adds again to the resistive forces.
>>
>> So.. If you allow more air go under the car It'll stay laminar near to
>> the ground but the uneven bottom parts of the vehicle will stir the
>> flow. This is why we wish to have smooth belly pan. But.. even the
>> stirring is added it still resists less the vehicle movement due the
>> more equal air flow around the car. It moves the negative pressure
>> point closer to the middle of the trunk and allows more air to pass in
>> laminar flow.
>>
>> I saw this effect already in 2005 while driving a lot on highways. I
>> had an opportunity to drive bulky EV with 100 mile range and highly
>> accurate measurement devices as full time job for years. (not just
>> driving but trying to find ways to prevent LCP-afterburners)
>>
>> I know there has been a lot of threads in here about the aerodynamics
>> during past 20 years. So let's get this summarized again so we do not
>> need to dig out our mid 1990's laptops. :P
>>
>> -Jukka
>>
>> http://www.google.com/profiles/jarviju#about
>>
>>
>> 2012/9/12 Martin WINLOW <[hidden email]>:
>> > Well, less frontal area (less tyre frontal area) for starters and I'm
>> sure there is a separate aerodynamic factor at playas well to do with the
>> venturi effect... made less detrimental to efficiency with a smaller air
>> gap - which is one reason why F1 cars ride so low...
>> >
>> > MW
>> >
>> >
>> > On 12 Sep 2012, at 13:37, Jukka Järvinen wrote:
>> >
>> >> Suspension set to the lowest setting. Why ?
>> >>
>> >> I've noticed that setting it high adds efficiency. (Brusa made Wh
>> >> meter was used)
>> >>
>> >> So Model-S in this case could have been more efficient by doing that.
>> >>
>> >> My conclusion was that more air passes underneath the vehicle and
>> >> lessens the negative pressure in the rear.
>> >>
>> >> Can anyone else in here concur ?
>> >>
>> >> -akkuJukka
>> >>
>> >>
>> >> http://www.google.com/profiles/jarviju#about
>> >>
>> >>
>> >> 2012/9/12 brucedp5 <[hidden email]>:
>> >>>
>> >>> The Tesla-S is still the electric range king
>> >>>
>> >>>
>> http://www.plugincars.com/whats-real-world-range-tesla-model-s-124318.html
>> >>> [image] What's the Real-World Range of the Tesla Model S?
>> >>> By Eric Loveday  Sep 10 2012
>> >>>
>> >>> [image] Tesla Model S
>> >>> Tesla's spectacular Model S electric sedan grabs headlines on a daily
>> basis,
>> >>> but the key metric for an electric vehicle is its real-world range.
>> Until
>> >>> recently, we could only post Tesla's estimated range rating of 265
>> miles for
>> >>> the 85-kWh version of the Model S, but now there's been some real-world
>> >>> testing, conducted by Motor Trend, which proves that Tesla wasn't off
>> the
>> >>> mark by much.
>> >>>
>> >>> Recently, the folks at Motor Trend took a Model S for an extended road
>> trip.
>> >>> After a mixed driving test from El Segundo, Calif. to San Diego and
>> back,
>> >>> the staff at Motor Trend discovered that the Model S is easily capable
>> of
>> >>> covering 238 miles on a full charge.
>> >>>
>> >>> Motor Trend posted this after completing its lengthy test drive in the
>> Tesla
>> >>> Model S: "The total range—adding the unused 4 miles—would be 238. Yes,
>> 238
>> >>> is 11 percent short of 265. Moreover, it was done while being very
>> stingy
>> >>> with performance (for the most part). Is that 265 actually valid? If
>> you
>> >>> drive predominately at highway speeds, then probably not. But were we
>> to
>> >>> have included more medium-speed roads (long stretches at 45-50 miles
>> per
>> >>> hour) well, possibly."
>> >>>
>> >>> Motor Trend operated the Model S with the A/C in the off position, but
>> had
>> >>> the vehicle's ventilation system turned on. Cruise control was set at
>> 65 mph
>> >>> and the crew set the Model S' air suspension to its lowest setting.
>> >>>
>> >>> At 238 miles, the efficiency of the Model S, with its 85 kWh battery
>> pack,
>> >>> is 2.8 miles per kilowatt hour. That's not very efficient for a small
>> >>> electric car like the Nissan LEAF or Honda Fit EV, but the Model S is a
>> >>> significantly larger vehicle. While the Model S is breaking new
>> >>> technological ground in many ways, these numbers do not indicate a
>> >>> revolutionary change in efficiency.
>> >>>
>> >>> But in the end, the Model S still managed to return more range than any
>> >>> other mass produced electric vehicle ever tested by a major
>> publication. So,
>> >>> whether it's 238 or 265 miles, the 85-kWh version of the Tesla Model S
>> is,
>> >>> as of right now, the electric range king.
>> >>> [© 2012 PluginCars.com ]
>> >
>> >
>> >
>> >
>> > -------------- next part --------------
>> > An HTML attachment was scrubbed...
>> > URL:
>> http://lists.sjsu.edu/mailman/private/ev/attachments/20120912/a35cb876/attachment.html
>> > _______________________________________________
>> > | Moratorium on drag racing discussion is in effect.
>> > | Please take those discussions elsewhere.  Thanks.
>> > |
>> > | REPLYING: address your message to [hidden email] only.
>> > | Multiple-address or CCed messages may be rejected.
>> > | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
>> > | OTHER HELP: http://evdl.org/help/
>> > | CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev
>>
>> _______________________________________________
>> | Moratorium on drag racing discussion is in effect.
>> | Please take those discussions elsewhere.  Thanks.
>> |
>> | REPLYING: address your message to [hidden email] only.
>> | Multiple-address or CCed messages may be rejected.
>> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
>> | OTHER HELP: http://evdl.org/help/
>> | CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev
>>
>
>
>
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> |
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|
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Re: Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S has 238mi range @65mph

Roland Wiench
In reply to this post by Jukka Järvinen-3
If you can drive down a long steep hill every day which I did for about 10
years with a EV, you could determine what the best body shape, best
suspension setting, wheel type and tires.

My EV has the air suspension system, where I can lower or rise the front,
rear or any side of the vehicle.  The front has a wedge shape fiberglass
nose that is extended about one foot out in the center and deflect the air
off to the sides.

The EV is a 77 El Camino that has a hinge up glass hatch back that is shape
smoothly from the top roof of the cab and slopes all the way down to the
tail gate.

The wheels are 24 lb CenterLine rated at 2200 lbs and the tires are Michelin
X LRR also rated at 2200 lbs at 50 psi.

The down hill road course is 3.57 miles long from the top crest of the hill
and all the way into my garage.  It consist of 1 mile of steep grade hill
that descends 1 mile in about 500 feet, another mile of a slight down hills
that goes to level and then up a exit grade for about 200 feet to the next
road.

>From this exit, the road goes down and up two times for the next mile.  I
then turn left which is again down hill for 0.57 miles right into my garage.

The road surface is a small concrete surface with those fine cut in joint
lines which are only 1/4 inch apart.  There is no bump bump when you drive
over them.

The suspension setting in the standard mode, where the EV is dead level,
with the frame 5.5 inches off the payment, the rear tires have exactly 2200
lbs on them with 50 psi.  The front tires have 1200 lbs on them at 35 psi.
The front and rear tires have the same deflection rate of 0.5 inch which is
taken up by the sidewalls of the tire and not transfer to the face of the
tire.

The EV comes off the exit at 35 mph on the down hill run.  This is the only
time I have to use any battery power to get the EV up to 35 mph.  I then let
off the accelerator which the battery and motor ampere indicates 0 amperes.

The DC-DC Converters are off line at this time while the inverter-alternator
comes on line at 1100 rpm excitation rpm.  This units generates 13.5 to 14.5
vdc up to 135 amps and 110 vdc up to 7kw which is converter to 120 vac 60 hz
at 5kw.  During the down hill run, these units may indicate up to 100 amps
if I have all my heaters on to slow down this EV when it is icy.

On a clear dry no wind down hill run at about 70 F degrees, with no
additional load on the drive motor, except for 14.4 vdc 4 amps on the motor
control, the EV will increase in speed from 35 mph to 85 mph on the first
one mile down hill section.  The next mile, it will slow down from 85 mph to
60 mph to the exit.

Entering the exit, the EV slows down at 55 mph and exits at 35 mph. Going
down, up, down, up again the speeds ranges from 35 to 45 and to 35 again.
Getting to my left turn off, I actually have the brake the EV for the first
time to slow it down to 25 mph.

I then can drive down the drive way with no additional power all the way
into my garage.

A old geezer neighbor of mine, told me if you lower the front end keeping
the rear up, the vehicle will coast longer down hill.  Try that to show him
and it did not make any difference to what I can measure in time and speed.

His theory was if the rear is up higher than the front, the vehicle is
always coasting down hill even if the vehicle is on a level. This is why
they had larger diameter wheels on the rear than on the front back in the
1800's.


Roland


----- Original Message -----
From: "Jukka Järvinen" <[hidden email]>
To: "Electric Vehicle Discussion List" <[hidden email]>
Sent: Thursday, September 13, 2012 6:08 AM
Subject: Re: [EVDL] Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S
has 238mi range @65mph


I can see how the teardrops tail is very sharp due the surface tension
of the liquid while moving ahead on a surface. It's another effect
there. Drop of liquid is rounder while flying through air.

What it comes to submarines I can also see how they made a compromise
between frictions and maneuverability. Very sharp head and tail would
be optimal as they do on ocean liners (while they have the "torpedo"
which they sit on). But most of this is debatable.

How accurate measurement is available from Model-S ? So if one would
drive certain route through several times on different suspension
settings. We might be able to determine something. Would be good to
get most of the variables in the same region (SOC, air temp, humidity,
etc..)

Wind tunnel question. How do the engineers take in count the air
molecule inertia ? When shooting off the molecules they have different
state of tied in energy compared to molecule standing still while
vehicle rams to it. I'm sorry if I seem to be ignorant and showing off
my stupidity in various fields of physics. But somehow I feel this
still being on topic. :)

I've learned also more I know I know I do not know.

-akkuJukka
http://www.google.com/profiles/jarviju#about


2012/9/13 Dennis Miles <[hidden email]>:

> Akkujukka, Today must be the day to comment on your comments.  You
> said,"The same aerodynamic forces are in the same way forcing the
> perfectly round drop of water in free fall to take the tear shape."(This
> is
> related to understanding streamlining of any EV.) The perfectly round drop
> of water in free space without air movement passing by it is round due to
> the surface tension Just like a simple balloon. But in moving air such as
> falling thru the atmosphere, the droplet takes on a shape similar to a
> chicken egg, not exactly round but elongated and not a teardrop. the
> teardrop comes when the droplet is in contact with a surface such as a
> lady's cheek or a window pane because the surface contacting the drop
> elongates by the adhesion to the surface holding it back and the drop
> elongates into a teardrop shape. Take a hard boiled egg, lay it on its
> side
> and pass it thru a knife lying with the blade parallel with the flat
> surface removing about 1/3 of the egg, the part left larger end to the
> front is more streamlined. Look at a picture of a modern nuclear submarine
> view the Bow (Front) and Stern (Back) shapes, (the middle is like a simple
> pipe so ignore that), but the submarine moves thru water (Much more viscus
> than air) and learn streamlining from it, Notice no long pointy front, and
> not a blunt tail, Billions of dollars in research went into the shape of a
> submarine.
> Regards,
> *     Dennis *(EVprofessor)* Miles*
>   *(863)944-9913* (phone noon to midnight E.S.T.)
> *    reply to [hidden email]*
> +++++++++++++++++++++++++++++++++++++++++
> On Wed, Sep 12, 2012 at 12:20 PM, Jukka Järvinen
> <[hidden email]>wrote:
>
>> I've been told that the ground effect for F1 is merely a safety
>> factor. At those speeds vehicles "take off" if there is air under the
>> wings. Also they are looking for downforce not efficiency.
>>
>> I could feel the car becoming more flimsy on the high setup but at the
>> same time the Watts taken from batteries drop. Unfortunately I have
>> dismantled the vehicle, rebuilt it and sold it away.
>>
>> Currently the shoemaker do not have shoes (which is sad). So I cannot
>> go out for a spinn.
>>
>> But from what I've learned about aerodynamics the negative pressure is
>> the force which pulls the planes up in the air. This same negative
>> pressure is in the rear of the vehicle. And it "pulls" the car
>> backwards if you go fast enough. The positive pressure in the front is
>> not that significant.
>>
>> The same aerodynamic forces are in the same way forcing the perfectly
>> round drop of water in free fall to take the tear shape. More force
>> more drastic change in the shape.
>>
>> More frontal area, more air is "compressed" in the front to go by the
>> car. Just to be released back to the negative pressure field. At
>> certain point the air flow goes from laminar flow to turbulent. And it
>> adds again to the resistive forces.
>>
>> So.. If you allow more air go under the car It'll stay laminar near to
>> the ground but the uneven bottom parts of the vehicle will stir the
>> flow. This is why we wish to have smooth belly pan. But.. even the
>> stirring is added it still resists less the vehicle movement due the
>> more equal air flow around the car. It moves the negative pressure
>> point closer to the middle of the trunk and allows more air to pass in
>> laminar flow.
>>
>> I saw this effect already in 2005 while driving a lot on highways. I
>> had an opportunity to drive bulky EV with 100 mile range and highly
>> accurate measurement devices as full time job for years. (not just
>> driving but trying to find ways to prevent LCP-afterburners)
>>
>> I know there has been a lot of threads in here about the aerodynamics
>> during past 20 years. So let's get this summarized again so we do not
>> need to dig out our mid 1990's laptops. :P
>>
>> -Jukka
>>
>> http://www.google.com/profiles/jarviju#about
>>
>>
>> 2012/9/12 Martin WINLOW <[hidden email]>:
>> > Well, less frontal area (less tyre frontal area) for starters and I'm
>> sure there is a separate aerodynamic factor at playas well to do with the
>> venturi effect... made less detrimental to efficiency with a smaller air
>> gap - which is one reason why F1 cars ride so low...
>> >
>> > MW
>> >
>> >
>> > On 12 Sep 2012, at 13:37, Jukka Järvinen wrote:
>> >
>> >> Suspension set to the lowest setting. Why ?
>> >>
>> >> I've noticed that setting it high adds efficiency. (Brusa made Wh
>> >> meter was used)
>> >>
>> >> So Model-S in this case could have been more efficient by doing that.
>> >>
>> >> My conclusion was that more air passes underneath the vehicle and
>> >> lessens the negative pressure in the rear.
>> >>
>> >> Can anyone else in here concur ?
>> >>
>> >> -akkuJukka
>> >>
>> >>
>> >> http://www.google.com/profiles/jarviju#about
>> >>
>> >>
>> >> 2012/9/12 brucedp5 <[hidden email]>:
>> >>>
>> >>> The Tesla-S is still the electric range king
>> >>>
>> >>>
>> http://www.plugincars.com/whats-real-world-range-tesla-model-s-124318.html
>> >>> [image] What's the Real-World Range of the Tesla Model S?
>> >>> By Eric Loveday  Sep 10 2012
>> >>>
>> >>> [image] Tesla Model S
>> >>> Tesla's spectacular Model S electric sedan grabs headlines on a daily
>> basis,
>> >>> but the key metric for an electric vehicle is its real-world range.
>> Until
>> >>> recently, we could only post Tesla's estimated range rating of 265
>> miles for
>> >>> the 85-kWh version of the Model S, but now there's been some
>> >>> real-world
>> >>> testing, conducted by Motor Trend, which proves that Tesla wasn't off
>> the
>> >>> mark by much.
>> >>>
>> >>> Recently, the folks at Motor Trend took a Model S for an extended
>> >>> road
>> trip.
>> >>> After a mixed driving test from El Segundo, Calif. to San Diego and
>> back,
>> >>> the staff at Motor Trend discovered that the Model S is easily
>> >>> capable
>> of
>> >>> covering 238 miles on a full charge.
>> >>>
>> >>> Motor Trend posted this after completing its lengthy test drive in
>> >>> the
>> Tesla
>> >>> Model S: "The total range—adding the unused 4 miles—would be 238.
>> >>> Yes,
>> 238
>> >>> is 11 percent short of 265. Moreover, it was done while being very
>> stingy
>> >>> with performance (for the most part). Is that 265 actually valid? If
>> you
>> >>> drive predominately at highway speeds, then probably not. But were we
>> to
>> >>> have included more medium-speed roads (long stretches at 45-50 miles
>> per
>> >>> hour) well, possibly."
>> >>>
>> >>> Motor Trend operated the Model S with the A/C in the off position,
>> >>> but
>> had
>> >>> the vehicle's ventilation system turned on. Cruise control was set at
>> 65 mph
>> >>> and the crew set the Model S' air suspension to its lowest setting.
>> >>>
>> >>> At 238 miles, the efficiency of the Model S, with its 85 kWh battery
>> pack,
>> >>> is 2.8 miles per kilowatt hour. That's not very efficient for a small
>> >>> electric car like the Nissan LEAF or Honda Fit EV, but the Model S is
>> >>> a
>> >>> significantly larger vehicle. While the Model S is breaking new
>> >>> technological ground in many ways, these numbers do not indicate a
>> >>> revolutionary change in efficiency.
>> >>>
>> >>> But in the end, the Model S still managed to return more range than
>> >>> any
>> >>> other mass produced electric vehicle ever tested by a major
>> publication. So,
>> >>> whether it's 238 or 265 miles, the 85-kWh version of the Tesla Model
>> >>> S
>> is,
>> >>> as of right now, the electric range king.
>> >>> [© 2012 PluginCars.com ]
>> >
>> >
>> >
>> >
>> > -------------- next part --------------
>> > An HTML attachment was scrubbed...
>> > URL:
>> http://lists.sjsu.edu/mailman/private/ev/attachments/20120912/a35cb876/attachment.html
>> > _______________________________________________
>> > | Moratorium on drag racing discussion is in effect.
>> > | Please take those discussions elsewhere.  Thanks.
>> > |
>> > | REPLYING: address your message to [hidden email] only.
>> > | Multiple-address or CCed messages may be rejected.
>> > | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
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Re: Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S has 238mi range @65mph

Ruckus
Raising the rear relative to the front is called 'rake'.  It Does make a
difference at very high speeds. (100mph+).  Air getting under the air dam
is compressed under the length of the car.  By tilting the car up in the
back you release this pressure since the space is getting larger.
Increasing the rake even more creates low pressure under the car.  This can
increase drag and also increase high speed stability.  Rake adjustment is
critical to high speed handling and drag but only at Very high speed.
On Sep 13, 2012 9:29 AM, "Roland Wiench" <[hidden email]> wrote:

> If you can drive down a long steep hill every day which I did for about 10
> years with a EV, you could determine what the best body shape, best
> suspension setting, wheel type and tires.
>
> My EV has the air suspension system, where I can lower or rise the front,
> rear or any side of the vehicle.  The front has a wedge shape fiberglass
> nose that is extended about one foot out in the center and deflect the air
> off to the sides.
>
> The EV is a 77 El Camino that has a hinge up glass hatch back that is shape
> smoothly from the top roof of the cab and slopes all the way down to the
> tail gate.
>
> The wheels are 24 lb CenterLine rated at 2200 lbs and the tires are
> Michelin
> X LRR also rated at 2200 lbs at 50 psi.
>
> The down hill road course is 3.57 miles long from the top crest of the hill
> and all the way into my garage.  It consist of 1 mile of steep grade hill
> that descends 1 mile in about 500 feet, another mile of a slight down hills
> that goes to level and then up a exit grade for about 200 feet to the next
> road.
>
> >From this exit, the road goes down and up two times for the next mile.  I
> then turn left which is again down hill for 0.57 miles right into my
> garage.
>
> The road surface is a small concrete surface with those fine cut in joint
> lines which are only 1/4 inch apart.  There is no bump bump when you drive
> over them.
>
> The suspension setting in the standard mode, where the EV is dead level,
> with the frame 5.5 inches off the payment, the rear tires have exactly 2200
> lbs on them with 50 psi.  The front tires have 1200 lbs on them at 35 psi.
> The front and rear tires have the same deflection rate of 0.5 inch which is
> taken up by the sidewalls of the tire and not transfer to the face of the
> tire.
>
> The EV comes off the exit at 35 mph on the down hill run.  This is the only
> time I have to use any battery power to get the EV up to 35 mph.  I then
> let
> off the accelerator which the battery and motor ampere indicates 0 amperes.
>
> The DC-DC Converters are off line at this time while the
> inverter-alternator
> comes on line at 1100 rpm excitation rpm.  This units generates 13.5 to
> 14.5
> vdc up to 135 amps and 110 vdc up to 7kw which is converter to 120 vac 60
> hz
> at 5kw.  During the down hill run, these units may indicate up to 100 amps
> if I have all my heaters on to slow down this EV when it is icy.
>
> On a clear dry no wind down hill run at about 70 F degrees, with no
> additional load on the drive motor, except for 14.4 vdc 4 amps on the motor
> control, the EV will increase in speed from 35 mph to 85 mph on the first
> one mile down hill section.  The next mile, it will slow down from 85 mph
> to
> 60 mph to the exit.
>
> Entering the exit, the EV slows down at 55 mph and exits at 35 mph. Going
> down, up, down, up again the speeds ranges from 35 to 45 and to 35 again.
> Getting to my left turn off, I actually have the brake the EV for the first
> time to slow it down to 25 mph.
>
> I then can drive down the drive way with no additional power all the way
> into my garage.
>
> A old geezer neighbor of mine, told me if you lower the front end keeping
> the rear up, the vehicle will coast longer down hill.  Try that to show him
> and it did not make any difference to what I can measure in time and speed.
>
> His theory was if the rear is up higher than the front, the vehicle is
> always coasting down hill even if the vehicle is on a level. This is why
> they had larger diameter wheels on the rear than on the front back in the
> 1800's.
>
>
> Roland
>
>
> ----- Original Message -----
> From: "Jukka Järvinen" <[hidden email]>
> To: "Electric Vehicle Discussion List" <[hidden email]>
> Sent: Thursday, September 13, 2012 6:08 AM
> Subject: Re: [EVDL] Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S
> has 238mi range @65mph
>
>
> I can see how the teardrops tail is very sharp due the surface tension
> of the liquid while moving ahead on a surface. It's another effect
> there. Drop of liquid is rounder while flying through air.
>
> What it comes to submarines I can also see how they made a compromise
> between frictions and maneuverability. Very sharp head and tail would
> be optimal as they do on ocean liners (while they have the "torpedo"
> which they sit on). But most of this is debatable.
>
> How accurate measurement is available from Model-S ? So if one would
> drive certain route through several times on different suspension
> settings. We might be able to determine something. Would be good to
> get most of the variables in the same region (SOC, air temp, humidity,
> etc..)
>
> Wind tunnel question. How do the engineers take in count the air
> molecule inertia ? When shooting off the molecules they have different
> state of tied in energy compared to molecule standing still while
> vehicle rams to it. I'm sorry if I seem to be ignorant and showing off
> my stupidity in various fields of physics. But somehow I feel this
> still being on topic. :)
>
> I've learned also more I know I know I do not know.
>
> -akkuJukka
> http://www.google.com/profiles/jarviju#about
>
>
> 2012/9/13 Dennis Miles <[hidden email]>:
> > Akkujukka, Today must be the day to comment on your comments.  You
> > said,"The same aerodynamic forces are in the same way forcing the
> > perfectly round drop of water in free fall to take the tear shape."(This
> > is
> > related to understanding streamlining of any EV.) The perfectly round
> drop
> > of water in free space without air movement passing by it is round due to
> > the surface tension Just like a simple balloon. But in moving air such as
> > falling thru the atmosphere, the droplet takes on a shape similar to a
> > chicken egg, not exactly round but elongated and not a teardrop. the
> > teardrop comes when the droplet is in contact with a surface such as a
> > lady's cheek or a window pane because the surface contacting the drop
> > elongates by the adhesion to the surface holding it back and the drop
> > elongates into a teardrop shape. Take a hard boiled egg, lay it on its
> > side
> > and pass it thru a knife lying with the blade parallel with the flat
> > surface removing about 1/3 of the egg, the part left larger end to the
> > front is more streamlined. Look at a picture of a modern nuclear
> submarine
> > view the Bow (Front) and Stern (Back) shapes, (the middle is like a
> simple
> > pipe so ignore that), but the submarine moves thru water (Much more
> viscus
> > than air) and learn streamlining from it, Notice no long pointy front,
> and
> > not a blunt tail, Billions of dollars in research went into the shape of
> a
> > submarine.
> > Regards,
> > *     Dennis *(EVprofessor)* Miles*
> >   *(863)944-9913* (phone noon to midnight E.S.T.)
> > *    reply to [hidden email]*
> > +++++++++++++++++++++++++++++++++++++++++
> > On Wed, Sep 12, 2012 at 12:20 PM, Jukka Järvinen
> > <[hidden email]>wrote:
> >
> >> I've been told that the ground effect for F1 is merely a safety
> >> factor. At those speeds vehicles "take off" if there is air under the
> >> wings. Also they are looking for downforce not efficiency.
> >>
> >> I could feel the car becoming more flimsy on the high setup but at the
> >> same time the Watts taken from batteries drop. Unfortunately I have
> >> dismantled the vehicle, rebuilt it and sold it away.
> >>
> >> Currently the shoemaker do not have shoes (which is sad). So I cannot
> >> go out for a spinn.
> >>
> >> But from what I've learned about aerodynamics the negative pressure is
> >> the force which pulls the planes up in the air. This same negative
> >> pressure is in the rear of the vehicle. And it "pulls" the car
> >> backwards if you go fast enough. The positive pressure in the front is
> >> not that significant.
> >>
> >> The same aerodynamic forces are in the same way forcing the perfectly
> >> round drop of water in free fall to take the tear shape. More force
> >> more drastic change in the shape.
> >>
> >> More frontal area, more air is "compressed" in the front to go by the
> >> car. Just to be released back to the negative pressure field. At
> >> certain point the air flow goes from laminar flow to turbulent. And it
> >> adds again to the resistive forces.
> >>
> >> So.. If you allow more air go under the car It'll stay laminar near to
> >> the ground but the uneven bottom parts of the vehicle will stir the
> >> flow. This is why we wish to have smooth belly pan. But.. even the
> >> stirring is added it still resists less the vehicle movement due the
> >> more equal air flow around the car. It moves the negative pressure
> >> point closer to the middle of the trunk and allows more air to pass in
> >> laminar flow.
> >>
> >> I saw this effect already in 2005 while driving a lot on highways. I
> >> had an opportunity to drive bulky EV with 100 mile range and highly
> >> accurate measurement devices as full time job for years. (not just
> >> driving but trying to find ways to prevent LCP-afterburners)
> >>
> >> I know there has been a lot of threads in here about the aerodynamics
> >> during past 20 years. So let's get this summarized again so we do not
> >> need to dig out our mid 1990's laptops. :P
> >>
> >> -Jukka
> >>
> >> http://www.google.com/profiles/jarviju#about
> >>
> >>
> >> 2012/9/12 Martin WINLOW <[hidden email]>:
> >> > Well, less frontal area (less tyre frontal area) for starters and I'm
> >> sure there is a separate aerodynamic factor at playas well to do with
> the
> >> venturi effect... made less detrimental to efficiency with a smaller air
> >> gap - which is one reason why F1 cars ride so low...
> >> >
> >> > MW
> >> >
> >> >
> >> > On 12 Sep 2012, at 13:37, Jukka Järvinen wrote:
> >> >
> >> >> Suspension set to the lowest setting. Why ?
> >> >>
> >> >> I've noticed that setting it high adds efficiency. (Brusa made Wh
> >> >> meter was used)
> >> >>
> >> >> So Model-S in this case could have been more efficient by doing that.
> >> >>
> >> >> My conclusion was that more air passes underneath the vehicle and
> >> >> lessens the negative pressure in the rear.
> >> >>
> >> >> Can anyone else in here concur ?
> >> >>
> >> >> -akkuJukka
> >> >>
> >> >>
> >> >> http://www.google.com/profiles/jarviju#about
> >> >>
> >> >>
> >> >> 2012/9/12 brucedp5 <[hidden email]>:
> >> >>>
> >> >>> The Tesla-S is still the electric range king
> >> >>>
> >> >>>
> >>
> http://www.plugincars.com/whats-real-world-range-tesla-model-s-124318.html
> >> >>> [image] What's the Real-World Range of the Tesla Model S?
> >> >>> By Eric Loveday  Sep 10 2012
> >> >>>
> >> >>> [image] Tesla Model S
> >> >>> Tesla's spectacular Model S electric sedan grabs headlines on a
> daily
> >> basis,
> >> >>> but the key metric for an electric vehicle is its real-world range.
> >> Until
> >> >>> recently, we could only post Tesla's estimated range rating of 265
> >> miles for
> >> >>> the 85-kWh version of the Model S, but now there's been some
> >> >>> real-world
> >> >>> testing, conducted by Motor Trend, which proves that Tesla wasn't
> off
> >> the
> >> >>> mark by much.
> >> >>>
> >> >>> Recently, the folks at Motor Trend took a Model S for an extended
> >> >>> road
> >> trip.
> >> >>> After a mixed driving test from El Segundo, Calif. to San Diego and
> >> back,
> >> >>> the staff at Motor Trend discovered that the Model S is easily
> >> >>> capable
> >> of
> >> >>> covering 238 miles on a full charge.
> >> >>>
> >> >>> Motor Trend posted this after completing its lengthy test drive in
> >> >>> the
> >> Tesla
> >> >>> Model S: "The total range—adding the unused 4 miles—would be 238.
> >> >>> Yes,
> >> 238
> >> >>> is 11 percent short of 265. Moreover, it was done while being very
> >> stingy
> >> >>> with performance (for the most part). Is that 265 actually valid? If
> >> you
> >> >>> drive predominately at highway speeds, then probably not. But were
> we
> >> to
> >> >>> have included more medium-speed roads (long stretches at 45-50 miles
> >> per
> >> >>> hour) well, possibly."
> >> >>>
> >> >>> Motor Trend operated the Model S with the A/C in the off position,
> >> >>> but
> >> had
> >> >>> the vehicle's ventilation system turned on. Cruise control was set
> at
> >> 65 mph
> >> >>> and the crew set the Model S' air suspension to its lowest setting.
> >> >>>
> >> >>> At 238 miles, the efficiency of the Model S, with its 85 kWh battery
> >> pack,
> >> >>> is 2.8 miles per kilowatt hour. That's not very efficient for a
> small
> >> >>> electric car like the Nissan LEAF or Honda Fit EV, but the Model S
> is
> >> >>> a
> >> >>> significantly larger vehicle. While the Model S is breaking new
> >> >>> technological ground in many ways, these numbers do not indicate a
> >> >>> revolutionary change in efficiency.
> >> >>>
> >> >>> But in the end, the Model S still managed to return more range than
> >> >>> any
> >> >>> other mass produced electric vehicle ever tested by a major
> >> publication. So,
> >> >>> whether it's 238 or 265 miles, the 85-kWh version of the Tesla Model
> >> >>> S
> >> is,
> >> >>> as of right now, the electric range king.
> >> >>> [© 2012 PluginCars.com ]
> >> >
> >> >
> >> >
> >> >
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> >> > | Please take those discussions elsewhere.  Thanks.
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Re: Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S has 238mi range @65mph

Dennis Miles
In reply to this post by Roland Wiench
Roland, you said,"The road surface is a small concrete surface with those
fine cut in joint lines which are only 1/4 inch apart.  There is no bump
bump when you drive over them." In 1970 California was just starting to put
those extra groves on the roadway to let rainwater drain from the surface
and minimize hydroplaning which had only recently been then discovered. At
first they were cut straight along road parallel to the painted lines but
as you came to a curve they would throw a car off the road and wreck a
motorcycle so direction was changed 90 degrees so as to not push cars and
motorcycles of the road. Next year or two "Rain"Tires became popular so
most states do not "Groove the roads now. (The slots are in the tread.)
And, Roland, tell the old geezer to watch a cowboy movie, the front wheels
are smaller to fit under the wagon on turns, and the back wheels are larger
to carry the freight because the driver (Teamster) sits in the front.
bigger wheels give more square inches of road surface contact so a larger
load can be carried and more easily pulled by the horses.
Regards, *     Dennis *(EVprofessor)* Miles*
  *(863)944-9913* (phone noon to midnight E.S.T.)
*    reply to [hidden email]*

On Thu, Sep 13, 2012 at 11:27 AM, Roland Wiench <[hidden email]> wrote:

> If you can drive down a long steep hill every day which I did for about 10
> years with a EV, you could determine what the best body shape, best
> suspension setting, wheel type and tires.
>
> My EV has the air suspension system, where I can lower or rise the front,
> rear or any side of the vehicle.  The front has a wedge shape fiberglass
> nose that is extended about one foot out in the center and deflect the air
> off to the sides.
>
> The EV is a 77 El Camino that has a hinge up glass hatch back that is shape
> smoothly from the top roof of the cab and slopes all the way down to the
> tail gate.
>
> The wheels are 24 lb CenterLine rated at 2200 lbs and the tires are
> Michelin
> X LRR also rated at 2200 lbs at 50 psi.
>
> The down hill road course is 3.57 miles long from the top crest of the hill
> and all the way into my garage.  It consist of 1 mile of steep grade hill
> that descends 1 mile in about 500 feet, another mile of a slight down hills
> that goes to level and then up a exit grade for about 200 feet to the next
> road.
>
> >From this exit, the road goes down and up two times for the next mile.  I
> then turn left which is again down hill for 0.57 miles right into my
> garage.
>
> The road surface is a small concrete surface with those fine cut in joint
> lines which are only 1/4 inch apart.  There is no bump bump when you drive
> over them.
>
> The suspension setting in the standard mode, where the EV is dead level,
> with the frame 5.5 inches off the payment, the rear tires have exactly 2200
> lbs on them with 50 psi.  The front tires have 1200 lbs on them at 35 psi.
> The front and rear tires have the same deflection rate of 0.5 inch which is
> taken up by the sidewalls of the tire and not transfer to the face of the
> tire.
>
> The EV comes off the exit at 35 mph on the down hill run.  This is the only
> time I have to use any battery power to get the EV up to 35 mph.  I then
> let
> off the accelerator which the battery and motor ampere indicates 0 amperes.
>
> The DC-DC Converters are off line at this time while the
> inverter-alternator
> comes on line at 1100 rpm excitation rpm.  This units generates 13.5 to
> 14.5
> vdc up to 135 amps and 110 vdc up to 7kw which is converter to 120 vac 60
> hz
> at 5kw.  During the down hill run, these units may indicate up to 100 amps
> if I have all my heaters on to slow down this EV when it is icy.
>
> On a clear dry no wind down hill run at about 70 F degrees, with no
> additional load on the drive motor, except for 14.4 vdc 4 amps on the motor
> control, the EV will increase in speed from 35 mph to 85 mph on the first
> one mile down hill section.  The next mile, it will slow down from 85 mph
> to
> 60 mph to the exit.
>
> Entering the exit, the EV slows down at 55 mph and exits at 35 mph. Going
> down, up, down, up again the speeds ranges from 35 to 45 and to 35 again.
> Getting to my left turn off, I actually have the brake the EV for the first
> time to slow it down to 25 mph.
>
> I then can drive down the drive way with no additional power all the way
> into my garage.
>
> A old geezer neighbor of mine, told me if you lower the front end keeping
> the rear up, the vehicle will coast longer down hill.  Try that to show him
> and it did not make any difference to what I can measure in time and speed.
>
> His theory was if the rear is up higher than the front, the vehicle is
> always coasting down hill even if the vehicle is on a level. This is why
> they had larger diameter wheels on the rear than on the front back in the
> 1800's.
>
>
> Roland
>
>
> ----- Original Message -----
> From: "Jukka Järvinen" <[hidden email]>
> To: "Electric Vehicle Discussion List" <[hidden email]>
> Sent: Thursday, September 13, 2012 6:08 AM
> Subject: Re: [EVDL] Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S
> has 238mi range @65mph
>
>
> I can see how the teardrops tail is very sharp due the surface tension
> of the liquid while moving ahead on a surface. It's another effect
> there. Drop of liquid is rounder while flying through air.
>
> What it comes to submarines I can also see how they made a compromise
> between frictions and maneuverability. Very sharp head and tail would
> be optimal as they do on ocean liners (while they have the "torpedo"
> which they sit on). But most of this is debatable.
>
> How accurate measurement is available from Model-S ? So if one would
> drive certain route through several times on different suspension
> settings. We might be able to determine something. Would be good to
> get most of the variables in the same region (SOC, air temp, humidity,
> etc..)
>
> Wind tunnel question. How do the engineers take in count the air
> molecule inertia ? When shooting off the molecules they have different
> state of tied in energy compared to molecule standing still while
> vehicle rams to it. I'm sorry if I seem to be ignorant and showing off
> my stupidity in various fields of physics. But somehow I feel this
> still being on topic. :)
>
> I've learned also more I know I know I do not know.
>
> -akkuJukka
> http://www.google.com/profiles/jarviju#about
>
>
> 2012/9/13 Dennis Miles <[hidden email]>:
> > Akkujukka, Today must be the day to comment on your comments.  You
> > said,"The same aerodynamic forces are in the same way forcing the
> > perfectly round drop of water in free fall to take the tear shape."(This
> > is
> > related to understanding streamlining of any EV.) The perfectly round
> drop
> > of water in free space without air movement passing by it is round due to
> > the surface tension Just like a simple balloon. But in moving air such as
> > falling thru the atmosphere, the droplet takes on a shape similar to a
> > chicken egg, not exactly round but elongated and not a teardrop. the
> > teardrop comes when the droplet is in contact with a surface such as a
> > lady's cheek or a window pane because the surface contacting the drop
> > elongates by the adhesion to the surface holding it back and the drop
> > elongates into a teardrop shape. Take a hard boiled egg, lay it on its
> > side
> > and pass it thru a knife lying with the blade parallel with the flat
> > surface removing about 1/3 of the egg, the part left larger end to the
> > front is more streamlined. Look at a picture of a modern nuclear
> submarine
> > view the Bow (Front) and Stern (Back) shapes, (the middle is like a
> simple
> > pipe so ignore that), but the submarine moves thru water (Much more
> viscus
> > than air) and learn streamlining from it, Notice no long pointy front,
> and
> > not a blunt tail, Billions of dollars in research went into the shape of
> a
> > submarine.
> > Regards,
> > *     Dennis *(EVprofessor)* Miles*
> >   *(863)944-9913* (phone noon to midnight E.S.T.)
> > *    reply to [hidden email]*
> > +++++++++++++++++++++++++++++++++++++++++
> > On Wed, Sep 12, 2012 at 12:20 PM, Jukka Järvinen
> > <[hidden email]>wrote:
> >
> >> I've been told that the ground effect for F1 is merely a safety
> >> factor. At those speeds vehicles "take off" if there is air under the
> >> wings. Also they are looking for downforce not efficiency.
> >>
> >> I could feel the car becoming more flimsy on the high setup but at the
> >> same time the Watts taken from batteries drop. Unfortunately I have
> >> dismantled the vehicle, rebuilt it and sold it away.
> >>
> >> Currently the shoemaker do not have shoes (which is sad). So I cannot
> >> go out for a spinn.
> >>
> >> But from what I've learned about aerodynamics the negative pressure is
> >> the force which pulls the planes up in the air. This same negative
> >> pressure is in the rear of the vehicle. And it "pulls" the car
> >> backwards if you go fast enough. The positive pressure in the front is
> >> not that significant.
> >>
> >> The same aerodynamic forces are in the same way forcing the perfectly
> >> round drop of water in free fall to take the tear shape. More force
> >> more drastic change in the shape.
> >>
> >> More frontal area, more air is "compressed" in the front to go by the
> >> car. Just to be released back to the negative pressure field. At
> >> certain point the air flow goes from laminar flow to turbulent. And it
> >> adds again to the resistive forces.
> >>
> >> So.. If you allow more air go under the car It'll stay laminar near to
> >> the ground but the uneven bottom parts of the vehicle will stir the
> >> flow. This is why we wish to have smooth belly pan. But.. even the
> >> stirring is added it still resists less the vehicle movement due the
> >> more equal air flow around the car. It moves the negative pressure
> >> point closer to the middle of the trunk and allows more air to pass in
> >> laminar flow.
> >>
> >> I saw this effect already in 2005 while driving a lot on highways. I
> >> had an opportunity to drive bulky EV with 100 mile range and highly
> >> accurate measurement devices as full time job for years. (not just
> >> driving but trying to find ways to prevent LCP-afterburners)
> >>
> >> I know there has been a lot of threads in here about the aerodynamics
> >> during past 20 years. So let's get this summarized again so we do not
> >> need to dig out our mid 1990's laptops. :P
> >>
> >> -Jukka
> >>
> >> http://www.google.com/profiles/jarviju#about
> >>
> >>
> >> 2012/9/12 Martin WINLOW <[hidden email]>:
> >> > Well, less frontal area (less tyre frontal area) for starters and I'm
> >> sure there is a separate aerodynamic factor at playas well to do with
> the
> >> venturi effect... made less detrimental to efficiency with a smaller air
> >> gap - which is one reason why F1 cars ride so low...
> >> >
> >> > MW
> >> >
> >> >
> >> > On 12 Sep 2012, at 13:37, Jukka Järvinen wrote:
> >> >
> >> >> Suspension set to the lowest setting. Why ?
> >> >>
> >> >> I've noticed that setting it high adds efficiency. (Brusa made Wh
> >> >> meter was used)
> >> >>
> >> >> So Model-S in this case could have been more efficient by doing that.
> >> >>
> >> >> My conclusion was that more air passes underneath the vehicle and
> >> >> lessens the negative pressure in the rear.
> >> >>
> >> >> Can anyone else in here concur ?
> >> >>
> >> >> -akkuJukka
> >> >>
> >> >>
> >> >> http://www.google.com/profiles/jarviju#about
> >> >>
> >> >>
> >> >> 2012/9/12 brucedp5 <[hidden email]>:
> >> >>>
> >> >>> The Tesla-S is still the electric range king
> >> >>>
> >> >>>
> >>
> http://www.plugincars.com/whats-real-world-range-tesla-model-s-124318.html
> >> >>> [image] What's the Real-World Range of the Tesla Model S?
> >> >>> By Eric Loveday  Sep 10 2012
> >> >>>
> >> >>> [image] Tesla Model S
> >> >>> Tesla's spectacular Model S electric sedan grabs headlines on a
> daily
> >> basis,
> >> >>> but the key metric for an electric vehicle is its real-world range.
> >> Until
> >> >>> recently, we could only post Tesla's estimated range rating of 265
> >> miles for
> >> >>> the 85-kWh version of the Model S, but now there's been some
> >> >>> real-world
> >> >>> testing, conducted by Motor Trend, which proves that Tesla wasn't
> off
> >> the
> >> >>> mark by much.
> >> >>>
> >> >>> Recently, the folks at Motor Trend took a Model S for an extended
> >> >>> road
> >> trip.
> >> >>> After a mixed driving test from El Segundo, Calif. to San Diego and
> >> back,
> >> >>> the staff at Motor Trend discovered that the Model S is easily
> >> >>> capable
> >> of
> >> >>> covering 238 miles on a full charge.
> >> >>>
> >> >>> Motor Trend posted this after completing its lengthy test drive in
> >> >>> the
> >> Tesla
> >> >>> Model S: "The total range—adding the unused 4 miles—would be 238.
> >> >>> Yes,
> >> 238
> >> >>> is 11 percent short of 265. Moreover, it was done while being very
> >> stingy
> >> >>> with performance (for the most part). Is that 265 actually valid? If
> >> you
> >> >>> drive predominately at highway speeds, then probably not. But were
> we
> >> to
> >> >>> have included more medium-speed roads (long stretches at 45-50 miles
> >> per
> >> >>> hour) well, possibly."
> >> >>>
> >> >>> Motor Trend operated the Model S with the A/C in the off position,
> >> >>> but
> >> had
> >> >>> the vehicle's ventilation system turned on. Cruise control was set
> at
> >> 65 mph
> >> >>> and the crew set the Model S' air suspension to its lowest setting.
> >> >>>
> >> >>> At 238 miles, the efficiency of the Model S, with its 85 kWh battery
> >> pack,
> >> >>> is 2.8 miles per kilowatt hour. That's not very efficient for a
> small
> >> >>> electric car like the Nissan LEAF or Honda Fit EV, but the Model S
> is
> >> >>> a
> >> >>> significantly larger vehicle. While the Model S is breaking new
> >> >>> technological ground in many ways, these numbers do not indicate a
> >> >>> revolutionary change in efficiency.
> >> >>>
> >> >>> But in the end, the Model S still managed to return more range than
> >> >>> any
> >> >>> other mass produced electric vehicle ever tested by a major
> >> publication. So,
> >> >>> whether it's 238 or 265 miles, the 85-kWh version of the Tesla Model
> >> >>> S
> >> is,
> >> >>> as of right now, the electric range king.
> >> >>> [© 2012 PluginCars.com ]
> >> >
> >> >
> >> >
> >> >
> >> > -------------- next part --------------
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> >> > URL:
> >>
> http://lists.sjsu.edu/mailman/private/ev/attachments/20120912/a35cb876/attachment.html
> >> > _______________________________________________
> >> > | Moratorium on drag racing discussion is in effect.
> >> > | Please take those discussions elsewhere.  Thanks.
> >> > |
> >> > | REPLYING: address your message to [hidden email] only.
> >> > | Multiple-address or CCed messages may be rejected.
> >> > | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> >> > | OTHER HELP: http://evdl.org/help/
> >> > | CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev
> >>
> >> _______________________________________________
> >> | Moratorium on drag racing discussion is in effect.
> >> | Please take those discussions elsewhere.  Thanks.
> >> |
> >> | REPLYING: address your message to [hidden email] only.
> >> | Multiple-address or CCed messages may be rejected.
> >> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
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> >>
> >
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> > | Please take those discussions elsewhere.  Thanks.
> > |
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>
> _______________________________________________
> | Moratorium on drag racing discussion is in effect.
> | Please take those discussions elsewhere.  Thanks.
> |
> | REPLYING: address your message to [hidden email] only.
> | Multiple-address or CCed messages may be rejected.
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>
> _______________________________________________
> | Moratorium on drag racing discussion is in effect.
> | Please take those discussions elsewhere.  Thanks.
> |
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> | Multiple-address or CCed messages may be rejected.
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Re: Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S has 238mi range @65mph

Hoegberg .
In reply to this post by Jukka Järvinen-3

Hi Jukka&co

Read here:

http://ecomodder.com/forum/showthread.php/index-phil-knox-aerodynamics-seminars-mod-data-lists-7118.html

http://ecomodder.com/forum/showthread.php/aeromodding-1930s-38-mpg-70-mph-model-t-92.html  :-)

http://ecomodder.com/forum/showthread.php/5th-generation-civic-hatchback-improving-aerodynamics-312.html

http://ecomodder.com/forum/showthread.php/phil-knox-fleet-34-years-aeromodding-1280.html

http://ecomodder.com/forum/showthread.php/german-experimentation-low-cd-automobiles-1930s-325.html

http://ecomodder.com/forum/showthread.php/2000-honda-insight-14-better-mpg-80-km-18930-5.html 

http://www.youtube.com/watch?v=5V2FgwN_re4 

Sam W. have done bicycling in 130 kmh ...... !  (81mph) on flat road..


http://ecomodder.com/forum/tool-aero-rolling-resistance.php

B.R.
/ John
Sweden
-----------------
Ps.
Eva/Bill:
that Alu on your salt-bikes "floor panel", at the right side (camera-place) looks like it would make *a lot* of forces in high speeds, am I wrong?
is it a reason for this design and material,  
room for improvement?



> From: [hidden email]
> Date: Thu, 13 Sep 2012 15:08:39 +0300
> To: [hidden email]
> Subject: Re: [EVDL] Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S has 238mi range @65mph
>
> I can see how the teardrops tail is very sharp due the surface tension
> of the liquid while moving ahead on a surface. It's another effect
> there. Drop of liquid is rounder while flying through air.
>
> What it comes to submarines I can also see how they made a compromise
> between frictions and maneuverability. Very sharp head and tail would
> be optimal as they do on ocean liners (while they have the "torpedo"
> which they sit on). But most of this is debatable.
>
> How accurate measurement is available from Model-S ? So if one would
> drive certain route through several times on different suspension
> settings. We might be able to determine something. Would be good to
> get most of the variables in the same region (SOC, air temp, humidity,
> etc..)
>
> Wind tunnel question. How do the engineers take in count the air
> molecule inertia ? When shooting off the molecules they have different
> state of tied in energy compared to molecule standing still while
> vehicle rams to it. I'm sorry if I seem to be ignorant and showing off
> my stupidity in various fields of physics. But somehow I feel this
> still being on topic. :)
>
> I've learned also more I know I know I do not know.
>
> -akkuJukka
> http://www.google.com/profiles/jarviju#about
>
>
> 2012/9/13 Dennis Miles <[hidden email]>:
> > Akkujukka, Today must be the day to comment on your comments.  You
> > said,"The same aerodynamic forces are in the same way forcing the
> > perfectly round drop of water in free fall to take the tear shape."(This is
> > related to understanding streamlining of any EV.) The perfectly round drop
> > of water in free space without air movement passing by it is round due to
> > the surface tension Just like a simple balloon. But in moving air such as
> > falling thru the atmosphere, the droplet takes on a shape similar to a
> > chicken egg, not exactly round but elongated and not a teardrop. the
> > teardrop comes when the droplet is in contact with a surface such as a
> > lady's cheek or a window pane because the surface contacting the drop
> > elongates by the adhesion to the surface holding it back and the drop
> > elongates into a teardrop shape. Take a hard boiled egg, lay it on its side
> > and pass it thru a knife lying with the blade parallel with the flat
> > surface removing about 1/3 of the egg, the part left larger end to the
> > front is more streamlined. Look at a picture of a modern nuclear submarine
> > view the Bow (Front) and Stern (Back) shapes, (the middle is like a simple
> > pipe so ignore that), but the submarine moves thru water (Much more viscus
> > than air) and learn streamlining from it, Notice no long pointy front, and
> > not a blunt tail, Billions of dollars in research went into the shape of a
> > submarine.
> > Regards,
> > *     Dennis *(EVprofessor)* Miles*
> >   *(863)944-9913* (phone noon to midnight E.S.T.)
> > *    reply to [hidden email]*
> > +++++++++++++++++++++++++++++++++++++++++
> > On Wed, Sep 12, 2012 at 12:20 PM, Jukka Järvinen <[hidden email]>wrote:
> >
> >> I've been told that the ground effect for F1 is merely a safety
> >> factor. At those speeds vehicles "take off" if there is air under the
> >> wings. Also they are looking for downforce not efficiency.
> >>
> >> I could feel the car becoming more flimsy on the high setup but at the
> >> same time the Watts taken from batteries drop. Unfortunately I have
> >> dismantled the vehicle, rebuilt it and sold it away.
> >>
> >> Currently the shoemaker do not have shoes (which is sad). So I cannot
> >> go out for a spinn.
> >>
> >> But from what I've learned about aerodynamics the negative pressure is
> >> the force which pulls the planes up in the air. This same negative
> >> pressure is in the rear of the vehicle. And it "pulls" the car
> >> backwards if you go fast enough. The positive pressure in the front is
> >> not that significant.
> >>
> >> The same aerodynamic forces are in the same way forcing the perfectly
> >> round drop of water in free fall to take the tear shape. More force
> >> more drastic change in the shape.
> >>
> >> More frontal area, more air is "compressed" in the front to go by the
> >> car. Just to be released back to the negative pressure field. At
> >> certain point the air flow goes from laminar flow to turbulent. And it
> >> adds again to the resistive forces.
> >>
> >> So.. If you allow more air go under the car It'll stay laminar near to
> >> the ground but the uneven bottom parts of the vehicle will stir the
> >> flow. This is why we wish to have smooth belly pan. But.. even the
> >> stirring is added it still resists less the vehicle movement due the
> >> more equal air flow around the car. It moves the negative pressure
> >> point closer to the middle of the trunk and allows more air to pass in
> >> laminar flow.
> >>
> >> I saw this effect already in 2005 while driving a lot on highways. I
> >> had an opportunity to drive bulky EV with 100 mile range and highly
> >> accurate measurement devices as full time job for years. (not just
> >> driving but trying to find ways to prevent LCP-afterburners)
> >>
> >> I know there has been a lot of threads in here about the aerodynamics
> >> during past 20 years. So let's get this summarized again so we do not
> >> need to dig out our mid 1990's laptops. :P
> >>
> >> -Jukka
> >>
> >> http://www.google.com/profiles/jarviju#about
> >>
> >>
> >> 2012/9/12 Martin WINLOW <[hidden email]>:
> >> > Well, less frontal area (less tyre frontal area) for starters and I'm
> >> sure there is a separate aerodynamic factor at playas well to do with the
> >> venturi effect... made less detrimental to efficiency with a smaller air
> >> gap - which is one reason why F1 cars ride so low...
> >> >
> >> > MW
> >> >
> >> >
> >> > On 12 Sep 2012, at 13:37, Jukka Järvinen wrote:
> >> >
> >> >> Suspension set to the lowest setting. Why ?
> >> >>
> >> >> I've noticed that setting it high adds efficiency. (Brusa made Wh
> >> >> meter was used)
> >> >>
> >> >> So Model-S in this case could have been more efficient by doing that.
> >> >>
> >> >> My conclusion was that more air passes underneath the vehicle and
> >> >> lessens the negative pressure in the rear.
> >> >>
> >> >> Can anyone else in here concur ?
> >> >>
> >> >> -akkuJukka
> >> >>
> >> >>
> >> >> http://www.google.com/profiles/jarviju#about
> >> >>
> >> >>
> >> >> 2012/9/12 brucedp5 <[hidden email]>:
> >> >>>
> >> >>> The Tesla-S is still the electric range king
> >> >>>
> >> >>>
> >> http://www.plugincars.com/whats-real-world-range-tesla-model-s-124318.html
> >> >>> [image] What's the Real-World Range of the Tesla Model S?
> >> >>> By Eric Loveday  Sep 10 2012
> >> >>>
> >> >>> [image] Tesla Model S
> >> >>> Tesla's spectacular Model S electric sedan grabs headlines on a daily
> >> basis,
> >> >>> but the key metric for an electric vehicle is its real-world range.
> >> Until
> >> >>> recently, we could only post Tesla's estimated range rating of 265
> >> miles for
> >> >>> the 85-kWh version of the Model S, but now there's been some real-world
> >> >>> testing, conducted by Motor Trend, which proves that Tesla wasn't off
> >> the
> >> >>> mark by much.
> >> >>>
> >> >>> Recently, the folks at Motor Trend took a Model S for an extended road
> >> trip.
> >> >>> After a mixed driving test from El Segundo, Calif. to San Diego and
> >> back,
> >> >>> the staff at Motor Trend discovered that the Model S is easily capable
> >> of
> >> >>> covering 238 miles on a full charge.
> >> >>>
> >> >>> Motor Trend posted this after completing its lengthy test drive in the
> >> Tesla
> >> >>> Model S: "The total range—adding the unused 4 miles—would be 238. Yes,
> >> 238
> >> >>> is 11 percent short of 265. Moreover, it was done while being very
> >> stingy
> >> >>> with performance (for the most part). Is that 265 actually valid? If
> >> you
> >> >>> drive predominately at highway speeds, then probably not. But were we
> >> to
> >> >>> have included more medium-speed roads (long stretches at 45-50 miles
> >> per
> >> >>> hour) well, possibly."
> >> >>>
> >> >>> Motor Trend operated the Model S with the A/C in the off position, but
> >> had
> >> >>> the vehicle's ventilation system turned on. Cruise control was set at
> >> 65 mph
> >> >>> and the crew set the Model S' air suspension to its lowest setting.
> >> >>>
> >> >>> At 238 miles, the efficiency of the Model S, with its 85 kWh battery
> >> pack,
> >> >>> is 2.8 miles per kilowatt hour. That's not very efficient for a small
> >> >>> electric car like the Nissan LEAF or Honda Fit EV, but the Model S is a
> >> >>> significantly larger vehicle. While the Model S is breaking new
> >> >>> technological ground in many ways, these numbers do not indicate a
> >> >>> revolutionary change in efficiency.
> >> >>>
> >> >>> But in the end, the Model S still managed to return more range than any
> >> >>> other mass produced electric vehicle ever tested by a major
> >> publication. So,
> >> >>> whether it's 238 or 265 miles, the 85-kWh version of the Tesla Model S
> >> is,
> >> >>> as of right now, the electric range king.
> >> >>> [© 2012 PluginCars.com ]
> >> >
> >> >
> >> >
> >> >
> >> > -------------- next part --------------
> >> > An HTML attachment was scrubbed...
> >> > URL:
> >> http://lists.sjsu.edu/mailman/private/ev/attachments/20120912/a35cb876/attachment.html
> >> > _______________________________________________
> >> > | Moratorium on drag racing discussion is in effect.
> >> > | Please take those discussions elsewhere.  Thanks.
> >> > |
> >> > | REPLYING: address your message to [hidden email] only.
> >> > | Multiple-address or CCed messages may be rejected.
> >> > | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> >> > | OTHER HELP: http://evdl.org/help/
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> >>
> >> _______________________________________________
> >> | Moratorium on drag racing discussion is in effect.
> >> | Please take those discussions elsewhere.  Thanks.
> >> |
> >> | REPLYING: address your message to [hidden email] only.
> >> | Multiple-address or CCed messages may be rejected.
> >> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> >> | OTHER HELP: http://evdl.org/help/
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> >>
> >
> >
> >
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> > | Please take those discussions elsewhere.  Thanks.
> > |
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>
> _______________________________________________
> | Moratorium on drag racing discussion is in effect.
> | Please take those discussions elsewhere.  Thanks.
> |
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Kinect, Reconstructme (was: Aerodynamics)

Bill Dube
The selection of diamond plate surface on the sidecar platform is
mainly driven by aesthetics. The surface also is required to be large
enough and strong enough to support (in theory) the weight of a 60 kg
"monkey" (AKA "Passenger").

There are many details of the skin shape and construction that merit
refinement to reduce aerodynamic drag. We are aware of the need, but
have not worked our way down the long list of priorities to those
line items yet.

Having said that, we are in the very beginnings of the process of
doing a 3D scan of the as-built vehicle so we can have the _actual_
shape to then run a "Computational Fluid Dynamics" (CFD) simulation.
At the suggestion of an expert in 3D scanning, we bought a Microsoft
Kinect for Windows 3D camera. (This is a variant of the Kinect used
with the X-box with different firmware.)
http://en.wikipedia.org/wiki/Kinect

There is a shareware package called Reconstructme that uses the
Kinect to produce a 3D "point cloud" of whatever surface you scan
with the Kinect.
http://reconstructme.net/

Hopefully, we will be able to make a 3D scan of the KillaJoule
similar to this example 3D scan of a Fiat 500:
http://reconstructme.net/2012/03/06/incredible-scan-of-a-fiat-500c/

All this is a bit of a hurdle for us, but getting the 3D scan is the
vital first step towards an accurate CFD simulation, leading directly
to the goal of minimal aero drag. Then will come the iterative
process of altering the virtual body shape, running the simulation on
the modified shape, evaluating the simulation results, altering the
shape, etc. Surrounding this iteration loop will be the modification
and testing in reality.

Bill and Eva


At 11:38 AM 9/25/2012, John from Sweden wrote:

>Ps.
>Eva/Bill:
>that Alu on your salt-bikes "floor panel", at the right side
>(camera-place) looks like it would make *a lot* of forces in high
>speeds, am I wrong?
>is it a reason for this design and material,
>room for improvement?

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Re: Kinect, Reconstructme (was: Aerodynamics)

Roland Wiench
In reply to this post by Jukka Järvinen-3
Hello Bill,

Test out a surface of a golf ball.  The dimples reduce the air friction over
a simpler solid round ball.  This surface was tested on a vehicle with the
similar results.

Roland


----- Original Message -----
From: "Bill Dube" <[hidden email]>
To: "Electric Vehicle Discussion List" <[hidden email]>
Sent: Tuesday, September 25, 2012 1:31 PM
Subject: [EVDL] Kinect, Reconstructme (was: Aerodynamics)


> The selection of diamond plate surface on the sidecar platform is
> mainly driven by aesthetics. The surface also is required to be large
> enough and strong enough to support (in theory) the weight of a 60 kg
> "monkey" (AKA "Passenger").
>
> There are many details of the skin shape and construction that merit
> refinement to reduce aerodynamic drag. We are aware of the need, but
> have not worked our way down the long list of priorities to those
> line items yet.
>
> Having said that, we are in the very beginnings of the process of
> doing a 3D scan of the as-built vehicle so we can have the _actual_
> shape to then run a "Computational Fluid Dynamics" (CFD) simulation.
> At the suggestion of an expert in 3D scanning, we bought a Microsoft
> Kinect for Windows 3D camera. (This is a variant of the Kinect used
> with the X-box with different firmware.)
> http://en.wikipedia.org/wiki/Kinect
>
> There is a shareware package called Reconstructme that uses the
> Kinect to produce a 3D "point cloud" of whatever surface you scan
> with the Kinect.
> http://reconstructme.net/
>
> Hopefully, we will be able to make a 3D scan of the KillaJoule
> similar to this example 3D scan of a Fiat 500:
> http://reconstructme.net/2012/03/06/incredible-scan-of-a-fiat-500c/
>
> All this is a bit of a hurdle for us, but getting the 3D scan is the
> vital first step towards an accurate CFD simulation, leading directly
> to the goal of minimal aero drag. Then will come the iterative
> process of altering the virtual body shape, running the simulation on
> the modified shape, evaluating the simulation results, altering the
> shape, etc. Surrounding this iteration loop will be the modification
> and testing in reality.
>
> Bill and Eva
>
>
> At 11:38 AM 9/25/2012, John from Sweden wrote:
>
> >Ps.
> >Eva/Bill:
> >that Alu on your salt-bikes "floor panel", at the right side
> >(camera-place) looks like it would make *a lot* of forces in high
> >speeds, am I wrong?
> >is it a reason for this design and material,
> >room for improvement?
>
> _______________________________________________
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> | Please take those discussions elsewhere.  Thanks.
> |
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>

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Re: Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S has 238mi range @65mph

Hoegberg .
In reply to this post by Hoegberg .

Hi Jukka, did you see it? Some of the links was very interesting,  

http://ecomodder.com/forum/showthread.php/aerocivic-how-drop-your-cd-0-31-0-a-290.html"Aerocivic - how to drop your Cd from 0.31 to 0.17"   And the car will also look very nice..!   :-)/Joh

> From: [hidden email]
> To: [hidden email]
> Date: Tue, 25 Sep 2012 19:38:09 +0200
> Subject: Re: [EVDL] Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S has 238mi range @65mph
>
>
> Hi Jukka&co
>
> Read here:
>
> http://ecomodder.com/forum/showthread.php/index-phil-knox-aerodynamics-seminars-mod-data-lists-7118.html
>
> http://ecomodder.com/forum/showthread.php/aeromodding-1930s-38-mpg-70-mph-model-t-92.html  :-)
>
> http://ecomodder.com/forum/showthread.php/5th-generation-civic-hatchback-improving-aerodynamics-312.html
>
> http://ecomodder.com/forum/showthread.php/phil-knox-fleet-34-years-aeromodding-1280.html
>
> http://ecomodder.com/forum/showthread.php/german-experimentation-low-cd-automobiles-1930s-325.html
>
> http://ecomodder.com/forum/showthread.php/2000-honda-insight-14-better-mpg-80-km-18930-5.html 
>
> http://www.youtube.com/watch?v=5V2FgwN_re4 
>
> Sam W. have done bicycling in 130 kmh ...... !  (81mph) on flat road..
>
>
> http://ecomodder.com/forum/tool-aero-rolling-resistance.php
>
> B.R.
> / John
> Sweden
> -----------------
> Ps.
> Eva/Bill:
> that Alu on your salt-bikes "floor panel", at the right side (camera-place) looks like it would make *a lot* of forces in high speeds, am I wrong?
> is it a reason for this design and material,  
> room for improvement?
>
>
>
> > From: [hidden email]
> > Date: Thu, 13 Sep 2012 15:08:39 +0300
> > To: [hidden email]
> > Subject: Re: [EVDL] Aerodynamics. Was:Re: EVLN: Motor Trend found Tesla-S has 238mi range @65mph
> >
> > I can see how the teardrops tail is very sharp due the surface tension
> > of the liquid while moving ahead on a surface. It's another effect
> > there. Drop of liquid is rounder while flying through air.
> >
> > What it comes to submarines I can also see how they made a compromise
> > between frictions and maneuverability. Very sharp head and tail would
> > be optimal as they do on ocean liners (while they have the "torpedo"
> > which they sit on). But most of this is debatable.
> >
> > How accurate measurement is available from Model-S ? So if one would
> > drive certain route through several times on different suspension
> > settings. We might be able to determine something. Would be good to
> > get most of the variables in the same region (SOC, air temp, humidity,
> > etc..)
> >
> > Wind tunnel question. How do the engineers take in count the air
> > molecule inertia ? When shooting off the molecules they have different
> > state of tied in energy compared to molecule standing still while
> > vehicle rams to it. I'm sorry if I seem to be ignorant and showing off
> > my stupidity in various fields of physics. But somehow I feel this
> > still being on topic. :)
> >
> > I've learned also more I know I know I do not know.
> >
> > -akkuJukka
> > http://www.google.com/profiles/jarviju#about
> >
> >
> > 2012/9/13 Dennis Miles <[hidden email]>:
> > > Akkujukka, Today must be the day to comment on your comments.  You
> > > said,"The same aerodynamic forces are in the same way forcing the
> > > perfectly round drop of water in free fall to take the tear shape."(This is
> > > related to understanding streamlining of any EV.) The perfectly round drop
> > > of water in free space without air movement passing by it is round due to
> > > the surface tension Just like a simple balloon. But in moving air such as
> > > falling thru the atmosphere, the droplet takes on a shape similar to a
> > > chicken egg, not exactly round but elongated and not a teardrop. the
> > > teardrop comes when the droplet is in contact with a surface such as a
> > > lady's cheek or a window pane because the surface contacting the drop
> > > elongates by the adhesion to the surface holding it back and the drop
> > > elongates into a teardrop shape. Take a hard boiled egg, lay it on its side
> > > and pass it thru a knife lying with the blade parallel with the flat
> > > surface removing about 1/3 of the egg, the part left larger end to the
> > > front is more streamlined. Look at a picture of a modern nuclear submarine
> > > view the Bow (Front) and Stern (Back) shapes, (the middle is like a simple
> > > pipe so ignore that), but the submarine moves thru water (Much more viscus
> > > than air) and learn streamlining from it, Notice no long pointy front, and
> > > not a blunt tail, Billions of dollars in research went into the shape of a
> > > submarine.
> > > Regards,
> > > *     Dennis *(EVprofessor)* Miles*
> > >   *(863)944-9913* (phone noon to midnight E.S.T.)
> > > *    reply to [hidden email]*
> > > +++++++++++++++++++++++++++++++++++++++++
> > > On Wed, Sep 12, 2012 at 12:20 PM, Jukka Järvinen <[hidden email]>wrote:
> > >
> > >> I've been told that the ground effect for F1 is merely a safety
> > >> factor. At those speeds vehicles "take off" if there is air under the
> > >> wings. Also they are looking for downforce not efficiency.
> > >>
> > >> I could feel the car becoming more flimsy on the high setup but at the
> > >> same time the Watts taken from batteries drop. Unfortunately I have
> > >> dismantled the vehicle, rebuilt it and sold it away.
> > >>
> > >> Currently the shoemaker do not have shoes (which is sad). So I cannot
> > >> go out for a spinn.
> > >>
> > >> But from what I've learned about aerodynamics the negative pressure is
> > >> the force which pulls the planes up in the air. This same negative
> > >> pressure is in the rear of the vehicle. And it "pulls" the car
> > >> backwards if you go fast enough. The positive pressure in the front is
> > >> not that significant.
> > >>
> > >> The same aerodynamic forces are in the same way forcing the perfectly
> > >> round drop of water in free fall to take the tear shape. More force
> > >> more drastic change in the shape.
> > >>
> > >> More frontal area, more air is "compressed" in the front to go by the
> > >> car. Just to be released back to the negative pressure field. At
> > >> certain point the air flow goes from laminar flow to turbulent. And it
> > >> adds again to the resistive forces.
> > >>
> > >> So.. If you allow more air go under the car It'll stay laminar near to
> > >> the ground but the uneven bottom parts of the vehicle will stir the
> > >> flow. This is why we wish to have smooth belly pan. But.. even the
> > >> stirring is added it still resists less the vehicle movement due the
> > >> more equal air flow around the car. It moves the negative pressure
> > >> point closer to the middle of the trunk and allows more air to pass in
> > >> laminar flow.
> > >>
> > >> I saw this effect already in 2005 while driving a lot on highways. I
> > >> had an opportunity to drive bulky EV with 100 mile range and highly
> > >> accurate measurement devices as full time job for years. (not just
> > >> driving but trying to find ways to prevent LCP-afterburners)
> > >>
> > >> I know there has been a lot of threads in here about the aerodynamics
> > >> during past 20 years. So let's get this summarized again so we do not
> > >> need to dig out our mid 1990's laptops. :P
> > >>
> > >> -Jukka
> > >>
> > >> http://www.google.com/profiles/jarviju#about
> > >>
> > >>
> > >> 2012/9/12 Martin WINLOW <[hidden email]>:
> > >> > Well, less frontal area (less tyre frontal area) for starters and I'm
> > >> sure there is a separate aerodynamic factor at playas well to do with the
> > >> venturi effect... made less detrimental to efficiency with a smaller air
> > >> gap - which is one reason why F1 cars ride so low...
> > >> >
> > >> > MW
> > >> >
> > >> >
> > >> > On 12 Sep 2012, at 13:37, Jukka Järvinen wrote:
> > >> >
> > >> >> Suspension set to the lowest setting. Why ?
> > >> >>
> > >> >> I've noticed that setting it high adds efficiency. (Brusa made Wh
> > >> >> meter was used)
> > >> >>
> > >> >> So Model-S in this case could have been more efficient by doing that.
> > >> >>
> > >> >> My conclusion was that more air passes underneath the vehicle and
> > >> >> lessens the negative pressure in the rear.
> > >> >>
> > >> >> Can anyone else in here concur ?
> > >> >>
> > >> >> -akkuJukka
> > >> >>
> > >> >>
> > >> >> http://www.google.com/profiles/jarviju#about
> > >> >>
> > >> >>
> > >> >> 2012/9/12 brucedp5 <[hidden email]>:
> > >> >>>
> > >> >>> The Tesla-S is still the electric range king
> > >> >>>
> > >> >>>
> > >> http://www.plugincars.com/whats-real-world-range-tesla-model-s-124318.html
> > >> >>> [image] What's the Real-World Range of the Tesla Model S?
> > >> >>> By Eric Loveday  Sep 10 2012
> > >> >>>
> > >> >>> [image] Tesla Model S
> > >> >>> Tesla's spectacular Model S electric sedan grabs headlines on a daily
> > >> basis,
> > >> >>> but the key metric for an electric vehicle is its real-world range.
> > >> Until
> > >> >>> recently, we could only post Tesla's estimated range rating of 265
> > >> miles for
> > >> >>> the 85-kWh version of the Model S, but now there's been some real-world
> > >> >>> testing, conducted by Motor Trend, which proves that Tesla wasn't off
> > >> the
> > >> >>> mark by much.
> > >> >>>
> > >> >>> Recently, the folks at Motor Trend took a Model S for an extended road
> > >> trip.
> > >> >>> After a mixed driving test from El Segundo, Calif. to San Diego and
> > >> back,
> > >> >>> the staff at Motor Trend discovered that the Model S is easily capable
> > >> of
> > >> >>> covering 238 miles on a full charge.
> > >> >>>
> > >> >>> Motor Trend posted this after completing its lengthy test drive in the
> > >> Tesla
> > >> >>> Model S: "The total range—adding the unused 4 miles—would be 238. Yes,
> > >> 238
> > >> >>> is 11 percent short of 265. Moreover, it was done while being very
> > >> stingy
> > >> >>> with performance (for the most part). Is that 265 actually valid? If
> > >> you
> > >> >>> drive predominately at highway speeds, then probably not. But were we
> > >> to
> > >> >>> have included more medium-speed roads (long stretches at 45-50 miles
> > >> per
> > >> >>> hour) well, possibly."
> > >> >>>
> > >> >>> Motor Trend operated the Model S with the A/C in the off position, but
> > >> had
> > >> >>> the vehicle's ventilation system turned on. Cruise control was set at
> > >> 65 mph
> > >> >>> and the crew set the Model S' air suspension to its lowest setting.
> > >> >>>
> > >> >>> At 238 miles, the efficiency of the Model S, with its 85 kWh battery
> > >> pack,
> > >> >>> is 2.8 miles per kilowatt hour. That's not very efficient for a small
> > >> >>> electric car like the Nissan LEAF or Honda Fit EV, but the Model S is a
> > >> >>> significantly larger vehicle. While the Model S is breaking new
> > >> >>> technological ground in many ways, these numbers do not indicate a
> > >> >>> revolutionary change in efficiency.
> > >> >>>
> > >> >>> But in the end, the Model S still managed to return more range than any
> > >> >>> other mass produced electric vehicle ever tested by a major
> > >> publication. So,
> > >> >>> whether it's 238 or 265 miles, the 85-kWh version of the Tesla Model S
> > >> is,
> > >> >>> as of right now, the electric range king.
> > >> >>> [© 2012 PluginCars.com ]
> > >> >
> > >> >
> > >> >
> > >> >
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