"Wind tunnel" photos

InvisibleGold · 04-09-2006, 04:48 AM

Okay, so I took these months ago and got distracted. Basically, we had a snow storm and a strong wind (around 40 mph). The snow was light and car sat facing into the wind in a sort of "tunnel" of trees.

It's interesting to see where the snow blew off and where it stayed piled on. I'm no expert on aerodynamics so I can't give a good explanation.

http://www.waiveris.com/projects/hondai ... erophotos/

-John

InvisibleGold · 04-09-2006, 03:12 PM

UPDATE: My college roomate (an aero engineer who is not on this board) mentioned that while it looks like you could lower the drag by filling the snow areas, it is misleading. These are effectively the areas of lowest air pressure and thus where the snow isn't scrubbed away.

The best way to improve the efficiency would be to scrub away the "clean" areas first. (albiet a tough option). It sort of points out the removing the rear wiper isn't a big priority as much as perhaps the side mirrors. Second, is that it will be very difficult to improve on the efficiency without major reductions in frontal area. (for example, by lowering the roof a few inches)

Dougie · 04-09-2006, 06:20 PM

A chopped Insight could have significantly better fuel mileage. I feel like I'm sitting on the floor, and have about a foot of headroom. The mirrors should go, too, but are required by law.

I think there are two other big opportunities.

1.) Tires. If it takes 20 pounds to push a 2000 pound Insight across the garage floor, then the rolling resistance drag coefficient is 0.0100. The tires used in solar cars have coefficients of as little as 0.0023.

2.) Cooling system. The cooling system is designed (like on all cars) to handle the worst case scenario, something like "80 mph up a long grade at high altitude in 100 degree heat." Most of the time you don't need that, but the drag of the over-sized cooling system is still there.