"In surface vehicles, you also need to account for the
ground effects underneath the car."
Mayf, thanks for pointing out this very important
feature. As LSR types, we forget that Cp can be
effectively and positively impacted by air moving
under the vehicle just as much as air moving over it.
IMHO, it may even be better to improve Cp with air
under the car.
John
--- DrMayf <drmayf@teknett.com> wrote:
> Is that right? CAn you tell me the source of this? I
> know model rocket
> builders sometimes us the string approach to finding
> the Cp But I don't
> think real missiles, real airplanes, real cars use
> that method. Unless it
> goes into the wind tunnel or or uses CFD to find it,
> Cp is pretty hard to
> find. Every pressure over the entire surface of the
> vehicle has to be
> accounted for and that is not easily done. And
> becaue of turbulent flow may
> change with speed. On a free flight
> vehicle Cp is pretty
> important because of stability issues, however, for
> ground vehicles there is
> another more important factor and that is the front
> wheel (or rear wheel)
> steering. Those contact patches on the ground make
> up for a lot of
> instability that might have arisen from a misplaced
> Cp.
>
> IMHO
>
> mayf, out in Pahrump
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