gato azul wrote:
o.k. here my attempt to make a meaningful contribution for today
think about it for a bit.
as for the other question, IMHO the attempt would be to reduce wake size
(I use the term wake, in the context of the "disturbed" flow field behind the whole car/vehicle, the volume
where velocity is not equal to free stream velocity))
Most of the induced drag comes from wingtip
yes, but not all of it
I think I understand you here, and if so, I had the exact same thought while looking at Twinkies in the grocery store just now. (Don't ask me why.)
It seems to me that one of the bigger problems of the overall internal aerodynamics of the car is the fact that air is drawn in from different areas of the car at different rates relative to the car's speed. That is, the side pods draw in air at A amount per X MPH, air box ancillaries
draw in air at B amount per X MPH and so on. That's to say nothing of the flow rerouting that occurs inside the car to cool electronics, oil, etc. So, it stands to reason that if the air is drawn in at different rates, it would also tend to vent at different rates. If so, that doesn't sound very efficient.
The faster a car goes, the more air it draws in, the greater the need to vent, and this is (EDIT: or would seem to be) true for all inducted air, regardless of the individual, varying rates. So, why not do it at once? What if a car had a centralized location to accept all
inducted air, save for that which goes to the engine, so that it all
could be vented at the same rate, one determined by a single variable rather than by many?
It seems to me that Lotus has perhaps done just that with the plenum that vents through a diffuser. That's clearly drag-reduction, just not in a way that we're accustomed to seeing.
Moreover, any slot-blowing, black-magic aerodynamic trickery would then have a source of predictable pressurized air.
Any of this make sense?