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Old 09-23-2020, 07:44 PM   #35 (permalink)
JulianEdgar
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I originally wrote:


So we're stuck in [Aerohead's] era where:
  • full wheel covers always gave the lowest drag
  • lift was caused by separation
  • airflow direction can be predicted by The Template
  • rear spoilers 'reach up' to flow
  • airflow separates at the end of the roof of notchbacks

.... and so on - all of which are wrong for any cars of the last 30 years.

Now what points has Aerohead answered?

Quote:
Originally Posted by aerohead View Post
* what is communicated to the viewer when, a multi-billion dollar multi-national corporation, which could possess/ construct, the best technology imaginable, choose MOON discs when they attempt land speed records.
Aerohead isn't keeping up with the literature. A good example of where he simply refuses to be guided by more recent references.

Quote:
* You've yet to master the Bernoulli theorem, so I advise you to keep your mouth shut until you do. Your way out of your depth. Book sales be damned!
Typical personal abuse - and note, no answer to the point. Aerohead still apparently believes that lift is caused by separation. At least 30 years out of date with cars.

Quote:
* The 'template' is a known quantity. It provides for fully-attached flow.
No doubt. But that doesn't therefore mean it can predict flow direction, as Aerohead often uses it to. Same old logical fallacy. Dogs have four legs, but not all four-legged animals are dogs.

Quote:
* All the spoilers listed in Hucho's 2nd-Edition were immersed in turbulence. And yes, they extend upwards through what would otherwise be turbulence, allowing the flow to intercept a target which will force the flow to follow a path of less severe pressure rise; and allow reattachment once the severe positive pressure is abated. Page - 61, ' One way to generate negative lift is a rear spoiler, the decisive feature being the relative height of 'separation' in relation to the rest of the body.' Hucho.
Page-282, 'negative lift values of... negatively inclined wings... increase with clearance above the body surfaces as they enter the ' undisturbed air flow.' ( what do you think Huchos' talking about? )
What was Hucho talking about? Well, self evidently, cars that mostly had a lot of separated flow! That is not the case with any car of basically the last 30 years.

Quote:
* Since notchbacks are a mutilation to a streamlined contour, one attempts to minimize the damage with whatever will pass muster with the stylist, designer, and production engineer. ( A Cd 0.22 notchback is not the same as a Cd 0.09 half-body ).
Meaningless stuff, I am afraid. Just go and talk to a professional car aerodynamicist about "mutilation to a streamlined contour". They'll just say: WTF?
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