GasPods: stick on airfoils

[DonBarletta]

GasPods are designed to make driving less of a drag. Chances are, at some point you’ve seen vehicles that were designed with streamlined little knobs on their hoods or roofs, to improve their aerodynamics. While such features have been shown to work, they generally haven’t been available as an aftermarket product. Now, however, if you want those knobs on your car, you can buy them – in the form of GasPods.

GasPods are designed to make driving less of a drag

[shovel]

No.

[UFO]

Data? I didn't think so.

[DonBarletta]

Sorry I didn't provide it in the original post. The GasPods data is on their website at - [link to site removed by admin - Google Gaspods, if you like.]

I have no financial interest in or compensation from GasPods in any way shape or form.

[UFO]

I see a lot of testimony and nice numbers, "Initial Field Studies validate the computational results with participants realizing fuel savings of between 4% and 19%", but no methodology or control to realize a solid baseline.

I'm thinking wind tunnel data would be reliable, but as seen on the Mitsubishi Evo, improvement is realistically less than 2% after extensive testing on placement.

[botsapper]

They contribute to very specific aircraft aerodynamic effects but everything else depends on ... location, location, location. Without CFD/tunnel testing on your particular vehicle shape/forms, applied at wrong locations these things may not contribute and even cost aero-efficiencies.


NASA - Micro-Vortex Generators Enhance Aircraft Performance

http://ntrs.nasa.gov/archive/nasa/ca...2010003963.pdf

http://www.mitsubishi-motors.com/cor...004/16E_03.pdf

[ChazInMT]

Why are these not properly corralled?

[Piwoslaw]

I'm willing to believe that VGs (or GasPods, or whatever you want to call them) may help in certain configurations, on certain cars. I'm also willing to believe that someone who knows something about both aerodynamics and A-B-A-B testing may be able to get an improvement. But unless s/he spends 8 hours per day at freeway speeds, it might not be worth the investment. The average driver who drives a block to the store 5 times a day is another story.

Reducing fuel consumption by 4% is almost believable, 19% is not. A Kammback is worth 5-10% on most cars, while a full boattail is 10-20%.

Oh, look, my horse has a VG on its forehead!

Should we park this in the U Corral? I'm not totally convinced since VG can help fuel economy, but the numbers (both FC reduction, and price) are outragous.

EDIT: Chaz got a better pic

[ConnClark]

While vortex generators are not unicorns they aren't easy to use correctly. I'm currently simulating vortex generators on my car with CFD software. Placement and sizing are critical to get a positive effect from them. Placement and sizing are also dependent on several factors like boundary layer thickness and flow separation.

Its very easy to create more drag using them. Here is a link to a picture of an unsuccessful placement I did. (Note the two large detachment bubbles)
ImageShack® - Online Photo and Video Hosting

[UFO]

Very cool simulation ConnClark!