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Old 04-25-2022, 12:19 PM   #195 (permalink)
aerohead
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diffuser angle

Quote:
Originally Posted by Phase View Post
Mock up rear diffuser with tape and poster board. Obviously wouldn’t make a real one till I get the rear smooth under tray

Real one would be set at about 10 degree angle, give or take depending on how well it can have airflow stay attached from the undertray. Also real version would have strakes/fins too
Historically, 'low-drag' diffusers are never at more than 4-degrees upsweep angle.
'(C)hange in a pressure distribution is highly significant for the origin of drag.' Wolf H. Hucho
'With a long diffuser, a notable reduction in drag can be achieved with a very small angle... however, this effect is only assured with a smooth underside..' Wolf H. Hucho.
'L)ow energy flow cannot withstand a pressure increase and therefore separates from the contour.' Wolf H. Hucho.
'Steep tapering...is limited as the resulting flow separation increases air drag.' Wolf H. Hucho.
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