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Nubo
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Air Speed Indicator

Fri Jun 04, 2010 8:55 am

Since the biggest determinant of power consumption is wind resistance, a bit of thinking about Air Speed vs. Ground Speed is in order. With a headwind of 20mph, a ground speed of 60 would be consuming power at the 80mph rate. Conversely, with a tailwind of 20mph, a 70mph cruise speed would only be consuming the equivalent of 50mph rate.

These are significant factors. In a way, the driver of a limited-range EV is a brethren of an airplane pilot. When determining range, it is Air Speed that concerns us rather than Ground Speed.

In that light, an Airspeed indicator would seem to be an appropriate instrument to include on the Leaf. When trying to optimize range, the driver should have that information rather than trying to derive it from second-order information such as the power consumption, or "building trees".

Of course, one must remain legal and reasonable in terms of ground speed, and I imagine legal departments might cringe at the notion that an airspeed indicator might cause someone somewhere to speed or be confused with road speed. I'd hope those concerns could be worked out by proper design.

And a pitot tube would be a cool conversation starter, and more useful than the solar panel, imho.
I noticed you're still working with polymers.

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LEAFer
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Re: Air Speed Indicator

Fri Jun 04, 2010 9:13 am

Nubo wrote:And a pitot tube would be a cool conversation starter, and more useful than the solar panel, imho.
YES! And it would allow you to "optimize" your tracking distance while drafting 8-) (oops ... that would be a liability issue ... oh well, we'll have to wait for after market :twisted: )
2011 Silver SL+QC [Mfg: 11/2010] 36mo/15k LEASE
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Dav
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Re: Air Speed Indicator

Fri Jun 04, 2010 11:33 am

Of course, for the best mileage, people would always want to travel with a tailwind.

No telling where they might end up, but they will get there having consumed less fuel! :o

palmermd
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Re: Air Speed Indicator

Fri Jun 04, 2010 11:44 am

Dav wrote:Of course, for the best mileage, people would always want to travel with a tailwind.

No telling where they might end up, but they will get there having consumed less fuel! :o

http://www.wired.com/autopia/2010/06/do ... -the-wind/

http://skepticblog.org/2010/05/27/saili ... -the-wind/

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AndyH
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Re: Air Speed Indicator

Fri Jun 04, 2010 1:09 pm

Nubo wrote:Since the biggest determinant of power consumption is wind resistance...
Above 45mph...
Nubo wrote:j...a bit of thinking about Air Speed vs. Ground Speed is in order. With a headwind of 20mph, a ground speed of 60 would be consuming power at the 80mph rate. Conversely, with a tailwind of 20mph, a 70mph cruise speed would only be consuming the equivalent of 50mph rate.
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Source: The New Electric Vehicles: A Clean & Quiet Revolution, Michael Hackleman, 1996, 0962958875

BrendanDolan
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Location: Redwood City, CA
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Re: Air Speed Indicator

Fri Jun 04, 2010 1:10 pm

Well, if you have a pitot tube, then somewhere you need a static port. Imagine waxing over that little guy when you're trying to get the shine back into the paint... :lol:

Total load makes more sense to me though, as you can climb a hill with a tailwind and be in worse shape than going down a hill into a headwind.

That all being said, rigging up a pitot/static system wouldn't be that hard, especially if you mounted the gauges boy racer style on the A pillar.
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AndyH
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Location: San Antonio

Re: Air Speed Indicator

Fri Jun 04, 2010 1:34 pm

Here we are - pitot and static in one assembly for $26.

http://www.aircraftspruce.com/catalog/i ... t15144.php
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:D

Bicster
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Re: Air Speed Indicator

Fri Jun 04, 2010 1:36 pm

Nissan needs to drop some new info fast, before we all go insane.
Reserved on April 20, 2010 - Never purchased

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DeaneG
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Re: Air Speed Indicator

Fri Jun 04, 2010 2:03 pm

Bicster wrote:Nissan needs to drop some new info fast, before we all go insane.
:D You have to imagine that their marketing people must be as busy right now refining the messages as their engineers are finishing the car.
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Bicster
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Re: Air Speed Indicator

Fri Jun 04, 2010 2:12 pm

DeaneG wrote:
Bicster wrote:Nissan needs to drop some new info fast, before we all go insane.
:D You have to imagine that their marketing people must be as busy right now refining the messages as their engineers are finishing the car.
My wife is a tech writer, so I imagine the marketing people and writers being frustrated with the engineers and managers constantly changing stuff that they've previously told them was set in stone. :lol:
Reserved on April 20, 2010 - Never purchased

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