DRS downforce numbers.

[hardingfv32]

I think the study was about developing a asymmetrical will application.

Total drag reduction means for the whole car, correct?

If we ASSUME drag is proportional to down-force among the deferent aero regions of the car and that the rear wing produce 30% of the cars down-force, then the rear wing itself would produce half the drag and down-force when the DRS is open.

Brian

[machin]

Total drag reduction means for the whole car, correct?

Yeah

if the rear wing produce 30% of the cars down-force, then the rear wing itself would produce half the drag [snip!] when the DRS is open.

That's what my simulation suggestions... would be interesting to see if anyone does any cfd if they get the same answer... I doubt if it would directly relate to the downforce though as I'm sure it will also affect the wing efficiency too...

[Pierce89]

What does 30 points mean anyway? Is it a percentage? Is it just an arbitrary number? PR speak? Does anyone actually know? Scarbs, can you translate?

A point is a change of 0.001 in -CL(coefficient of downforce). A thirty point reduction would be say -CL 2.100 to -CL 2.070. To then get raw force numbers you have to multiply that coefficient by frontal area,air density and square of speed to get DF in newtons.
The equation is:L = 0.5 * Cl * A * r * V^2

Where L is lift (or in your case, downforce), Cl the lift coefficient, A the area of the body in question, r the air density, and V the velocity of the fluid flow


Sorry, totally missed Shelly's post

[shelly]

In the analysis of Alonso drs failure at last GP, James Allen reports that drs stuck in open position causes an estimated downforce loss of 70-80 points.
http://www.jamesallenonf1.com/2013/05/f ... n-bahrain/
This is more than I expected (I thought the whole rear wing assembly was around 80-90 points worth)

[variante]

This is more than I expected (I thought the whole rear wing assembly was around 80-90 pints worth)

judging from the images i could see, it looked like the flap was creating a little bit of lift since its leading edge was tilted upward. So it wasn't just open and aero neutral. Also, this situation could cause disastrous consequences on beam wing and diffuser.

[Richard]

It was discussed some time ago in the thread "how much is a point of downforce".

http://www.f1technical.net/forum/viewto ... f=6&t=8250

[NoDivergence]

I don't have my paper on me, but I did some CFD, the L/D ratio increases when using DRS. However, the angle of attack of the wings and flap deflection angle makes a difference in this due to regulations

[TDH]

I did some research regarding the influence of DRS. I designed my own system and tested it myself. This design isn't really comparable to a F1 rear wing but it gives you an idea.

I designed a wing from 2 NACA airfoils. The ratio main wing/ movable wing = 15/10. The profile used is NACA 7420.

AoA main wing = 9°
AoA movable wing = 14°

Closed position Open position
Cl = 0,1751291 Cl = 0,13368589
Cd= 0,029548446 Cd = 0,019446404

You get a drag reduction of 34,19 %

[NoDivergence]

How do you define the AOA of your moveable flap? with relation to the flow or to the main airfoil?

[TDH]

In relation to the airflow