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Old 07-06-2016, 07:09 PM   #25 (permalink)
aerohead
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gently

Quote:
Originally Posted by mikesheiman View Post
Ok, so it tapers in too quickly...would it actually be better off as a hatchback e.g. no taper at all? I know even some hatchbacks get about 0.3 CD.

And I think I see what you mean about the sides. As in they push air up, only to curve into an area where it's quickly pulled down a bit, thus causing a vacuum/turbulence area? How much CD would you guess that issue alone costs and what's a good way to fix it (simply keep sloping upward and very gently start curving downward to meet the very side/tail area)?
Yes,the initial inward curvature must be very gentle to protect the boundary layer.
This SMART Car is very good

For lower drag,just add length,while respecting the gentle slope

If you envisioned the car as an upright wing,you'd use the 3.92:1 section (between #4 and #5)

As a 3D flow body you'd opt for the minimum drag half body based on the 2.5:1 teardrop.
The curvatures of these shapes would be your guide as far as slopes go.
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