Quote:
Originally Posted by jakobnev
I'd keep any interaction between the wake and the air passing around it to a minimum, because any transfer of momentum between them should (according to Newton) lower base pressure.
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I don't think that is correct in the way Cd is trialling it.
If you can raise the pressure in the wake by adding airflow to it, base pressure will be increased and so drag reduced.
A la a 'blown wake' in fact.
I don't actually think that Cd's approach will achieve that, but it's worth trying. And it's not an approach (ie with NACA ducts) that I have seen tried anywhere else at all.
If I saw this being done in an SAE tech paper, I'd be very interested in the results.