To make xpensives statement more visible I made a little graph. You can see that the useful range where the engine demands more air than the airbox can deliver is at relatively low speed. At this speed you will indeed have low pressure in the airbox. You can notice that at some race cars with restrictor, there you can see the airbox breathing while applying high revs on a standing car. In fact the airbox has to withstand the forces produced there.
data: engine with 2,4L at 18.000 1/min
Airbox with diameter of 15cm
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I guess this idea makes little sense for F1, the airbox is just to big for it and the speed where you get low pressure is therefore to low. Anyways there are other racing series where you have a restrictor and run at lower speeds.
So guys please make some comments about the idea of sucking/blowing the underside of a wing. It could well fit to a FSAE car in terms of speed and high downforce demand. I know you don’t necessarily need downforce there but when you have a high efficient wing you could produce enough downforce to get an advantage by this.
mep wrote:Last time I was a bit in a hurry because I was at work so I just fly over the thread. You where writing about sucking top surface but I and maybe others to think about sucking lower surface.
What I want to do is to keep airstream attached to the wings profile and therefore running it at higher angles of attack. For this I make several slits over whole wing span and connect them with the airbox. The engine doesn’t even need to suck anything in. It just provides low pressure and helps to keep air attached. Due to the low pressure and the higher airspeed you create more downforce during low speed and cornering.
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At higher car speed more and more air gets collected by the duct above the airbox and starts to blow through the same holes under the wing. This causes the air to detach from the profile. Increased mass flow, changed flow and reduced air speed under the wing rises the pressure and reduces drag and downforce at high speed. So you get all what you want high downforce at low speed and low drag at high speed.
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