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Old 04-03-2013, 05:52 PM   #27 (permalink)
aerohead
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beneficial and

Quote:
Originally Posted by KamperBob View Post
Back in the day with an air-cooled rear engine I have to wonder it detached flow was beneficial and intentional...
All the air-cooled engines of course have forced-air cooling from the generator shaft.So,in a sense,it doesn't matter where the air comes in from,as engine power is robbed to provide the pressure differential across the oil cooler and cooling fins.
That said,the flow separation,while lowering the base pressure behind,does maintain a downwash,with momentum carrying the airstream down on a collision course with the body.By locating the inlet at the site of the collision,you can harvest this downwash,easing the horsepower requirement of the cooling fan.
In a modern application,the ghost of Ferdinand Porsche might utilize NACA submerged inlets to bring air into the engine bay.
The Lange car form,which Porsche used,according to Hucho,had Cd 0.14-16 in scale-models,so you can imagine how attractive this might seem at a time when 'conventional' cars were Cd 0.6-7.
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