Window screen for motorcycle crosswind problem ?

[Cd]

I typed in 'screen' in the search box for the aerodynamics section here and got something like 250 pages of posts with "screen", so this is a dedicated post on the question.

Using a fine mesh window screen just might allow crosswinds to pass through an aerodynamic motorcycle fairing, yet provide enough surface area longitudinally to retain flow attachment, much the way that louvers do such as on this car :

So has anyone tested this yet ?

[aerohead]

Originally Posted by Cd

I typed in 'screen' in the search box for the aerodynamics section here and got something like 250 pages of posts with "screen", so this is a dedicated post on the question.

Using a fine mesh window screen just might allow crosswinds to pass through an aerodynamic motorcycle fairing, yet provide enough surface area longitudinally to retain flow attachment, much the way that louvers do such as on this car :

So has anyone tested this yet ?

The only way the louvers work is do to the fact that the area they conceal is non-aspirated.Air is pooling inside the louver,creating an environment for capturing vorticity which would allow the outer flow a 'surface' in which to skip over.
If the screen is open to a channel,the air will immediately make a right-angle turn into the void,destroying flow aft of it.

[Cd]

What about in something with an air pocket that is small like a motorcycle fairing ?
I'd love to see it tested. It would be so simple and cheap for someone with a motorcycle ( hell, i might even try it on my bicycle ( ...nah that's $ 12 i need for groceries ! )

The air pocket is tiny compared to a car, and there is strong airflow on both sides with both sides having equal pressure. My pea brain is convinced that it just might help !

After all, if Spandex can work to keep flow attached, i would think that screen could as well, just not as effectively.

[freebeard]

My thought experiment is two surfboard shapes, one above the other, with a band of trampoline mesh stretched between them. The semipermeable surface would trade air (at low velocity) between the high and low pressure areas, would it not?

[Cd]

I would guess that trampoline mesh is too tightly woven to allow crosswinds to pass through .

That is a damn clever idea for some other application though, since it is flexible, yet doesn't tear like spandex.

Thanks for suggesting that.

[freebeard]

I was pushing back against window screen. And I was looking at pieces of a 12' diameter frame at the recyclers, trying to figure out how to make a pipe and tarp canopy (shopping there is cheap entertainment).

I've lain under one looking up. You can see through it close up, like those pin-hole glasses. So, maybe 10-20% permeable.

It comes down to what % of the air you are diverting. A body could be ALL vents and scoops under the fabric and it would look seamless.

[Grant-53]

The mesh size will determine the speed of air flow through the screen and build up of a boundary layer. I would try 1/4 in. mesh along the side for starters.