Application of Bernoulli Equation should take care of that; equating velocity head to pressure head. As posted so often, check out Flow of Fluids by Crane, for example.
Good luck.
You get Lbs/sq Ft (pressure) as a result the speed of the air in a direction parallel to the surface. However, you also get pressure from air moving perpendicular to the surface. Bernoulli tells you how to calculate the former. I don't know how to calculate the latter.
Break the wind into the two components (parallel and perpendicular) and apply the two equations.
It's been a long time since my days back in school when we covered this. . . All I remember is that the shape of the surface has a substantial impact on the force. That's why when you stick your hand out the window of the car going down the road, spreading your fingers can have a significant effect on the force you feel. There's a constant that needs to be included in the equation which relates to the object shape, that constant often needs to be empirically derived. Some standard shapes have published constants -- Firetube alludes to the constant for semicircles in his second equation above, but does not indicate what shape the first equation is for (I'd suspect a circle or a square).
In cars (and aircraft?) there is some concern over wind resistance. Reletive motion between the object (vehicle) and the fluid (air) results in a force on the object and turbulence, etc. in the fluid.
The force is a function of the fluid properties, reletive velocity, shape and size of the object.
Right?
A lot depends on what you mean by "pressure".
What was the original purpose of the question?
