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Old 06-17-2020, 01:32 PM   #3 (permalink)
aerohead
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mesh and turbulence

Quote:
Originally Posted by freebeard View Post
Needs pix.





No mention of the mesh fence's effect on turbulence on the tunnel walls?
We'd have to talk with Layne and Gary Eaker, ( A2 Wind Tunnel) who consulted on DARKO's design.
The screen could be simply for Foreign Object protection to the honeycomb flow straighteners downstream.
It could also prevent jetsam, if clearing the flow straighteners, ever reaching the 560-hp fan's leading edges.
At DARKO's airspeeds, there's no reason to introduce turbulence since it's full-scale, and supercritical Reynolds number is achieved once to 20-mph air velocity.
The boundary layer buildup on floor,walls,and ceiling, is compensated for with the streamlined walls and ceiling.
Hucho says that any TBL on the floor will not effect drag measurements of a passenger car. I'll take him at his word, having personally run Volkswagen's tunnel for a decade.
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