Why was this FW Endplate design so popular?

[ringo]

Don't want to use the typical jargon but it energizes air flow between the gap of the wing elements. It works for multi element wings i suppose. See how the weir of the notch is at the leading edge of the top element?
It makes no real gain in straight line performance i guess, it's effects are noticeable in yaw.

Thanks for the insight.
When I first started looking at my FW photos again I noticed that many EP " notches"did line up with the upper elements. But then as I looked further I found that this was not the case in most of the pictures I have.



Would the same principle be in effect on this wing even though it doesn't line up with the upper elements?
Thanks

I really don't know, but it may not have to be exactly aligned. I think the wind tunnel or CFD tests dictate how and where the notch is in each case.

[BreezyRacer]

Obviously I cannot tell for sure but the flow image seems to have no to ground to it. Thus you can see the vortex flow to the underside of the wing.

[newbie]

that CFD image shows precisely what i said. a distint vortex shed earlier from the notched portion of the endplate, travelling quite differently compared to the endplate trailing edge vortex.

[ringo]

I made a wing my self, it,s not to scale or anything, just an arbitrary wing with the notch in the end plate. The wind speed is at 150mph hitting the car at an angle. It should sort of represent going through a turn.



The notch seems to allow air to flow over the top of the wing since the leeward side of the endplate is experiencing lower pressure. It could aid in keeping up the pressure on the element as well, as can be seen by the red crawling over onto the element.



I don't see 2 distinct vortexes at the tips of the endplate, but they are at the back corners of the end plate. This CFD could have been done with more detail but my pc is kinda slow.
I also failed to see any lines flowing under the element, but i think if the notch was made lower and i changed to edge radius of the notch, it could happen.
So i would agree to the notch allowing flow to go across the wing.

I will try one with a head wind and see if there is any effect from the notch; i might put 2 wheels behind the wing too.

[schumy7]

Wild guess:

If we look at where the notch is, the inside of the end plate has higher pressure than the outside. Ideally if we want to increase down force, we would try to hold the high pressure on the upper surface and not letting it out with a notch.

So my guess is that the notch is not something that helps the wing elements, but works only as a vortex generator. The vortex created would hit the wheel and make the flow over the wheel attach longer, reducing drag.

You don't see them on the 2009 front wings because the wings are wider and the vortex wouldn't hit the wheel.

Very random guess though.

[NormalChris]

Thanks for the input.

Did you happen to do a simulation on what happens on the the other sides endplate with flow from the same direction?

[newbie]

great effort, but i stand by what i said about shedding the top edge vortex...the previous CFD image posted looks more representative of old F1 geometry and the mesh resolution was probably finer, better capturing the vortex behavior!

[ringo]

Thanks for the input.

Did you happen to do a simulation on what happens on the the other sides endplate with flow from the same direction?

Yes, the vortex was more disticnt. I should have displayed it here.

[ringo]

great effort, but i stand by what i said about shedding the top edge vortex...the previous CFD image posted looks more representative of old F1 geometry and the mesh resolution was probably finer, better capturing the vortex behavior!

What do you mean exactly by shedding the top edge vortex? I see forced vortex shedding as something detrimental.
I know vortex can be beneficial in some cases, but with having the wheel right behind the plate. The vortex smashes right into the high pressure in front the rotating wheel.
I find the idea of distributing air over the elements more reasonable.
I am curious since Vortex shedding is something complicated, and in most cases it is an unwanted phenomena.


Concerning the mesh and the refinement of the cells, i tried, but it was too painfully slow.

And @ schumy7 about the pressure, it's not leaking pressure over the notch, if you look closely at the colour scale in the corner, and follow the colours; the notch is actually introducing high pressure over the wing element.
The blue is low pressure leeward side of the endplate that is sheilded from the flow, similar to the low pressure behind a car.
Check the red coloration from the top view.

I will run this again head on to get the vortex formation. I will also put a wheel behind the plate and see where the vortex goes. The vortex size is dependent on the thickness of the sheilded area behind the flow, the end plates are very thin so i won't be surprised if the vorteces are a little weak. But i am open to any opinion so hopefully i can try to observe more.

[newbie]

forcibly shedding vortices is something done to prevent the formation of a single, large vortex by creating more than one, smaller vortex/vortices. additionally, by shedding the vortex at a precise position you can use it in a more beneficial manner. just look at the staggered bargeboards on older F1 cars.
(http://www.aigars.info/wallpapers/tehni ... 600-1.jpeg)
all the various curls, turning vanes and strakes that you see on F1 cars have the purpose of creating carefully placed vortices which can help load the floor/wing/diffuser by inducing inwash/upwash/outwash etc as needed on the particular component.

[n_anirudh]

This is a similar work carried out with a 3 element rear wing..using 2 M prism elements,with no symmetry, for reasons to see variation in yaw..

As seen in the fig, which is at yaw 0, the vortex from the frontal face of the endplate rolls up along the outer edge downstream,leaving a low pressure on the sides.

[NormalChris]

Thanks for taking the effort to reply. Do you have any more pics of the sim? I'm not as knowledgeable as id like and seeing pressure distribution would help. If not, again, thanks.

[n_anirudh]

Well, there is noting too different happening apart fron the low pressure region the vortex creates as leaves the notch..

[NormalChris]

Thanks. I was interested because we were thinking of experimenting with this FW EP design on our car.

[crbassassin]

It seems like the end plate cut is not compatible with the upper element