3D modeling the effects of a natural wind tunnel

The Cold and Windy Days

It’s pretty windy and cold out in Cleveland right now:

(ht: earth :: a global map of wind, weather, and ocean conditions)

The Car

If you’ve seen some of my other posts on solar panels, etc., you’ll know I acquired a box of parts electric vehicle I’m aiming to run off solar. One of the challenges with this car, which is the factory equivalent of an ev-swapped Mercedes B-class, is aerodynamics. Sharing its body with twins in gasoline and diesel variations (and in current generations, plug-in hybrids), the aerodynamics could be better. It could be worse: it does have a vehicle under-pan, a spoiler, etc. but it has too large a front grill and radiator, and a boxy back end.

I’ll deal with the over-sized grill later (for simplicity, the radiator will probably stay in place). But, how about the tail end of the car… . What is the effect of that boxy back end on aerodymamics? With this wonderful wind tunnel sitting over the Great Lakes, we can see where the laminar flow ends based on where the snow gets deposited:

An Option

I’m unlikely to do anything extreme with the back end, though I have been enjoying https://ecomodder.com/, but no boat tails or anything too extreme for me just yet:

ht: https://www.aerocivic.com/

Other back ends: inspiration

Thinking about this back end, I have been looking closely at what Kia have done with the latest (2023) generation of Niro. And what they’ve done is compelling. They have an “aero blade” behind their C-Pillar to increase laminar flow on the back side of this little hatchback:

It looks pretty cool especially up close:

This is also something I could 3D print, and magnetically attach the the car and test. It won’t look as cool with an integrated LED light, but maybe the final version, if there is one will have some nice texture and add and accent of color. At the very least, I hope it will increase my highway ranges.

If I do go this route, I’ll probably 3D scan the exterior of the C-Pillar on my car with OpenDroneMap. No. It’s not a good idea, not relative to properly measuring it. But I’ll do it anyway because it is the hammer I have… .


If you have a ball pein hammer, then you could try for golf ball aerodynamics :wink:


You know what I forgot to do? Post my model of the back end!

26 photos, 10-ish minutes of processing, and an optimized back-end shape for my car. Priceless.