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Originally Posted by d0sitmatr
what you say sounds good, but its false.
I can promise you it doesnt make much of a difference regarding wind speed, what makes the most difference is angle.
if you had a nicely angled surface (say, 45*) then yes, you would see more air flow blockage, but full frontal isnt going to be any more than what its rated for.
screen is simply not very realistic material to work with for extreme blockage.
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"Rated for"?
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I can promise you it doesnt make much of a difference regarding wind speed, ...
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You sound very confident. However, this is opposed to everything I was taught in grad school about pressure, flow, velocity and how they relate to resistance to airflow. The velocity of the air makes a huge difference in flow resistance. In fact, the resistance to flow across any restriction increases as the
square of the velocity.
The formula is
V=4005*√VP, where
VP is the velocity pressure in inches of water (measured as the change in pressure, ΔP, across the screen). The formula indicates that as the air velocity increases linearly the resistance to flow by the screen increases exponentially. (4005 is just a constant and can be ignored here).
So I think I will stick to the engineering formulas that say as the vehicle's speed increases, the screen (vertical, slanted, whatever) will block a greater and greater proportion of the incoming air. How much screen, how many layers, or how small a mesh size are just engineering details to be worked out. But the idea of using mesh as a variable air block material is a good one.