Quote:
Originally Posted by instarx
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"Rated for"?
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read above, already answered
Quote:
Originally Posted by instarx
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.
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I am very confident, before anything, lets put grad school vs more than 12 yrs hands on
experience in the screening/aluminum industry, within a hurricane zone (S.FL.)
if your formula was to work, then every time we get even a heavy thunderstorm with 50+ mph winds (just about an every day occurrence in the summer), it would pull that screen right off the rails... every single time. (which would be good for me, since then Id have more work than I could keep up with)
if you doubt me, take a moment and actually look at the screens in your home, either wall or window.
you can push that screen out from the front with little effort. certainly much less force than 40-50 mph winds generate.
now, take that same screening material and put it at a 45 /.
now you have almost doubled its resistance. so yes, it would make an effective blocking method
IF you have a decent angle to work with. but as a straight on application, then your only going to see the basic rating of 34%.
remember, we are talking about almost the thickest screening material you can find, which is .13.
your average screen is .11