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Old 12-04-2020, 12:47 PM   #14 (permalink)
aerohead
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how good

Quote:
Originally Posted by Grant-53 View Post
At recumbents.com there is the shell design program that can be used to create a shell form. The file then can be used in CFD programs such as AutoDesk. The question as with all measuring devices is how good is good enough?
The 2015, ECORUNNER - V, by Delft Technical University, may have reported the lowest extant drag for a land vehicle. Cd 0.0512.
This would have to be considered within the context of a 3.8-sq-ft frontal area vehicle, averaging 15-mph ( burn - and - coast ), on a closed-course, perhaps completely shielded from any wind, or terrestrial boundary layer.
It is a 'three-wheeler', so, it might qualify for a 'fairing' on a velomobile.
The 2006 PAC car-II is also a three-wheeler, and formally held the low-drag record at, Cd 0.07. Perhaps at a higher Reynolds number than the ECORUNNER-V.
Only you can judge how far you want to push the CdA. And under what conditions.
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