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Old 01-29-2015, 06:29 PM   #20 (permalink)
aerohead
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high pressure

Quote:
Originally Posted by NickelB NL View Post
I.ve been thinking about it for days now. Afther reading a bit into mirror designs and the high preasure at the windshield and high turbulance around the a pillar.

What about spoilers/flaps to fill in the angle between fender and a pillar. A flat plate welded in or if ducktape wil hold for testing or other manners. But i my mind if you box in the high preasure at the base of the windshield and "cut" the air with the same plate for better attached flow on the sides and around the mirrors. Sorry for my schetchy explanation. I.ll try to make a hand drawn schetch and upload it
The stagnation bubble atop the cowl area is not responsible for flow over the windshield or A-pillars.It doesn't go anywhere,but rather travels along with the car,stuck right there.When the ventilation damper is open,this pressure pushes air into the HVAC system.
In a rain,you may see the air (pushing water ) go sideways at the bottom of the windshield,at a 45-degree angle at the top sides,and vertical in the center.
As MetroMPG mentioned,if you place a capping plate/fence near the A-pillar base,the transverse flow will trip over it,creating flow separation and turbulence right there.
Modern cars which have the valley between the A-pillars were designed for that.The fenders,hood,windshield,and A-pillars were all done from scratch to accommodate that feature.To dial that in on a car not designed for it might not be doable.If it could,you'd need,according to many new graduate engineers,and also mentioned ,top of the line CFD or a full-scale wind tunnel.
Personally,I'd recommend you spend your time elsewhere.
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