Multiple element wings

[godlameroso]

Wow...Thanks man, that's a really good article =D> . Seems multi element wings allow you to have, technically, a larger wing with less separation, as well as increasing the pressure differential. Also it seems that after 13 deg AOA the flow starts to become turbulent, but since the slot gaps tend to pull the wake of each previous element, in addition to maintaining a laminar flow across the interrelated surfaces. I guess teams use three elements on the front wing because of space constraints, and because eventually you get into the realm of diminishing returns.

What still puzzles me is why do front wings feature all those flip ups towards near the end plates, and in the middle of the wing elements in the Mclaren? Those small winglets can't possibly create much downforce, do they act like dive planes/turning vanes? Do they act in conjunction with the end plates? Or do they interact with other elements of the front wing? Kind of like how the old diffusers worked with the rear wings. Maybe the up wash they generate helps pull the air under the front wing.

[marekk]

Regarding multi element wings, if you notice carefully, the first element closest to the ground has the highest surface area, but also the lowest AOA, and each succeeding element has a lower surface area, albeit with a higher AOA. This is at least true with the fastest cars in testing so far. The same is true of the rear wing.

AoA for all elements in F1 wing is about the same (near stall AoA) - it's not the angle to the horizon, it's the angle to the direction of flow. And as every element changes direction of flow a little (you can't basicaly go beyond 10 degree AoA without separation), a next one works in already "curved" flow.

[horse]

Wow...Thanks man, that's a really good article =D>

You're welcome.

What still puzzles me is why do front wings feature all those flip ups towards near the end plates, and in the middle of the wing elements in the Mclaren? Those small winglets can't possibly create much downforce, do they act like dive planes/turning vanes? Do they act in conjunction with the end plates? Or do they interact with other elements of the front wing?

I think the front wing must go through a lot of CFD optimisation along with trial and error of new design ideas. Remember, the front wing also manages much of the airflow to the rear of the car and about the front wheel so there are a number of factors, along with sheer downforce, that the designers must consider.

What is interesting for me is the prevalence of closed end plates, such as on the RB, compared to the open one on the Mercedes/Brawn. Having it closed will improve the downforce of the wing, but Brawn decided the interactions with the front wheel compromised the aero too much, so vented some flow around the outside of the wheel. RB (and others) have managed to keep the end plate closed (with some small inward facing vents), getting the most downforce, and deal with the flow about the front wheels at the same time, which I think is quite an achievement.

[shelly]

@godlameroso: flip ups on endplates are for vortex trapping.

[godlameroso]

Is that why there appears to be a raised edge right at the leading edge of the flip ups as well as the wings?

http://staff.polito.it/luca.zannetti/nota_acc_sci.pdf

according to this paper by creating a small cavity at the leading edge, causes vortecies to be trapped, and said vortecies act like virtual flaps.

[horse]

Note that on the paper you reference the cavities are on the suction side, so I doubt the same process is being exploited on the wing. If they were, then they would be on the ground facing side of the foil.

I think the paper also notes that capturing a vortex with such a configuration is difficult without some suction being applied.

I am not sure that I am seeing the flip-ups you describe on the leading edge, anyway. There are often Gurney flaps on the trailing edge of F1 wings which, although they look like mini barn doors, allow foils to run at higher angles of attack without stalling.

See this article about the Gurney Flap

[godlameroso]

Sorry I've meant all this time to say those extra wings that are on top of the wings, Are they the reason the wings were bending closer to the ground at high speed?

[shelly]

@godlameroso: the article you found is interesting, but the 2d vortex trapping described in it is completely a different topic.

I intended that for flip ups you intended the curly shapes on the lower edge of the front wing endplate (in the mclaren also in another position, more central).
Those features are intended to trap tip vortices and exploit their upwash and the low pressure of their nucleus.

Extra winglets generate downforce and thy also contribute to bend the front wing towards the ground. Force toward the ground generated by the wing itself is much bigger, but more distributed.
I think anyway that the main function of these elements is managing flow towards fornt wheels.

[raymondu999]

@godlameroso: flip ups on endplates are for vortex trapping.

I think godlameroso is talking of front wing cascades and not flipups

[shelly]

@raymondu999: yes godlameroso had told so in his previous post and I have responded accordingly in my post above