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LibertyMKiii · 04-06-2018, 10:27 PM

I am doing version 1 of the body design as a catamaran.
Looking around on the inter-webs I found some various things that were quite interesting on the topic of near ground aerodynamics. I know that Solar EV college teams try to engineer their cars at speed to have neutral lift. We can see the top of the airfoil's shape would normally generate some lift except for the accelerated air speed under the car "squished" between the bottom and the ground creates the low pressure zone.

This image is quite common on this site which indicates an ideal shape for low drag, but my application needs some significant down-force.

Given that using larger diameter wheels will help reduce the rotation speed at 200mph I have the ability to build in some air gap under the car where I could take advantage of the ground effect principles.
This image is less common when searching the topic and appears that noticeable effects require the car body to be a significant height off the ground.

In this image the top version has the axle line and lowest part of the body as the highest drag of the various models... It seems to conflict with the above image.

This image is a bit more scientific.

And finally the manta-ray

I have done some significant changes to the car where the main chassis is very thin for making this section into a slim airfoil. The tallest part is the top of the 4.15" tire. The bottom of the chassis is exactly half way at the axle line around 2.15"
What are your thoughts on how effective this design idea might be?

04-06-2018, 10:27 PM	#46 (permalink)
LibertyMKiii EcoModding Lurker Join Date: Mar 2018 Location: Dallas, TX Posts: 35 Thanks: 0 Thanked 7 Times in 6 Posts	I am doing version 1 of the body design as a catamaran. Looking around on the inter-webs I found some various things that were quite interesting on the topic of near ground aerodynamics. I know that Solar EV college teams try to engineer their cars at speed to have neutral lift. We can see the top of the airfoil's shape would normally generate some lift except for the accelerated air speed under the car "squished" between the bottom and the ground creates the low pressure zone. This image is quite common on this site which indicates an ideal shape for low drag, but my application needs some significant down-force. Given that using larger diameter wheels will help reduce the rotation speed at 200mph I have the ability to build in some air gap under the car where I could take advantage of the ground effect principles. This image is less common when searching the topic and appears that noticeable effects require the car body to be a significant height off the ground. In this image the top version has the axle line and lowest part of the body as the highest drag of the various models... It seems to conflict with the above image. This image is a bit more scientific. And finally the manta-ray I have done some significant changes to the car where the main chassis is very thin for making this section into a slim airfoil. The tallest part is the top of the 4.15" tire. The bottom of the chassis is exactly half way at the axle line around 2.15" What are your thoughts on how effective this design idea might be? Last edited by LibertyMKiii; 04-06-2018 at 10:32 PM..