Red Bull RB10 Renault

[seinfeld]

I think Renault need to switch to air/water cooled Kers units. they are the only ones that are using air only!
Ferrari are using specific shell fluids for cooling, so is sauber . and mercedes also using air/water. Ferrari also using air/water for intercooler charging as well!!
This is where Renault is struggling. when the recharging happens, they are getting nowhere as there is too much heat being generated

[bhall]

Go and do some reading on wing vertical wing tips. Do not use the word stall as it is highly misleading regardless of your intentions and in an aerodynamics term completely incorrect.

[...]

The part that may confuse some people is that while it reduces drag it may have very small to nil to even positive effect on downforce. I am not saying it will but that in some scenarios it can.

[...]

I've described in great detail over the last couple of pages exactly what I meant. However, anyone merely skimming through it all may have missed not only that but any of the several instances in which I've detailed the inevitability of a loss of some downforce concurrent with drag reduction.

(I admit it; I'm long-winded, and I love words.)

It's simply impossible to increase pressure under a wing at any point and maintain full efficiency at the same time, because they are mutually exclusive goals. But, that's A-OK for a car that experiences peak drag forces at speeds well in excess of any speed where downforce is useful.

Put another way: absent the presence of moveable bodywork, which is banned save for limited circumstances, the ideal rear wing will operate at peak efficiency only up until the car reaches the highest speed in which peak downforce is needed for a turn, a speed generally much lower than a car's top-speed on any given circuit. From then on, as such levels of downforce are totally useless, because it's all just drag, the wing will get rid of it as best as it can.

The slots on the end plates of the RB10 are a step in that direction.

(Hey, no pictures this time.)

[gandharva]

I think Renault need to switch to air/water cooled Kers units. they are the only ones that are using air only!
Ferrari are using specific shell fluids for cooling, so is sauber . and mercedes also using air/water. Ferrari also using air/water for intercooler charging as well!!
This is where Renault is struggling. when the recharging happens, they are getting nowhere as there is too much heat being generated

That's on the side of the teams. Torro Rosso for example use air/water. Air/water has better cooling but is much heavier.

[Blackout]

STR is using one air-air intercooler in each sidepod AFAIK. RBR and Caterham too.
Lotus might be using an air-water system.

[trinidefender]

Go and do some reading on wing vertical wing tips. Do not use the word stall as it is highly misleading regardless of your intentions and in an aerodynamics term completely incorrect.

[...]

The part that may confuse some people is that while it reduces drag it may have very small to nil to even positive effect on downforce. I am not saying it will but that in some scenarios it can.

[...]

I've described in great detail over the last couple of pages exactly what I meant. However, anyone merely skimming through it all may have missed not only that but any of the several instances in which I've detailed the inevitability of a loss of some downforce concurrent with drag reduction.

(I admit it; I'm long-winded, and I love words.)

It's simply impossible to increase pressure under a wing at any point and maintain full efficiency at the same time, because they are mutually exclusive goals. But, that's A-OK for a car that experiences peak drag forces at speeds well in excess of any speed where downforce is useful.

Put another way: absent the presence of moveable bodywork, which is banned save for limited circumstances, the ideal rear wing will operate at peak efficiency only up until the car reaches the highest speed in which peak downforce is needed for a turn, a speed generally much lower than a car's top-speed on any given circuit. From then on, as such levels of downforce are totally useless, because it's all just drag, the wing will get rid of it as best as it can.

The slots on the end plates of the RB10 are a step in that direction.

(Hey, no pictures this time.)

The way you are looking at a wing is that even though the vortex is there that it is still producing lift (downforce). The problem with this theory is that when a vortex is rotating around the end of a wing it stops all lift production of that section of the wing. There are two things you can do to alleviate this problem, or you can combine both ideas as well. These are:

1. Use a wingtip at a neutral angle of attack to reduce the pressure differential at the edge of the wingtip. This reduces the size and strength of the vortex. This also moves the vortex away from the lift producing section of the wing increasing the effective span of the wing and increasing its aspect ratio and making it more efficient. This method is used by all F1 cars, it is the rear wing end plates (RWEP) themselves. The RWEP reduce the pressure differential between the two sides of the wing and move the vortex away from the edge of the wing.

2. Use slots at the edge to equalise the pressure between both sides of the wing. The smaller the pressure differential between two sides of a wing at the tip, the smaller and weaker the vortex formed will be. Yes at first impression it may seem obvious that reducing the pressure differential between two sides of a wing will reduce lift. However the wing will still be producing some lift as there is still a pressure differential there. If you factor in that when you reduce the size and strength of the vortex you increase the effective lifting area of the wing and increase the effective span and aspect ratio even though part of that recovered surface will not be as efficient.

Imagine you have a wing that if no vortex formed at the wingtip the lift would be "X" and the effective lifting area would be "Y". When you introduce the wingtip vortex the values might go to (X-10) and (Y-10). Now when you add the tip slots such as what RedBull are using the effective lifting area can go to (X-6) because of the smaller vortices and the and lift might go to (X-4) because of more lifting surface. Even though you gain back most of the lifting surface that was lost that regained area is not as efficient as the rest of the wing which is why the lift which is regained does not equal the surface area regained.

[Gaz.]

STR is using one air-air intercooler in each sidepod AFAIK. RBR and Caterham too.
Lotus might be using an air-water system.

I thought RBR were also using water/air chargecoolers?

[bhall]

The way you are looking at a wing...

I feel like we're having a bit of a communication breakdown here, because I'm saying things, and then you're repeating them back to me almost as if I haven't said them at all.

In any case, I've definitely filled this thread with enough of my rambling for the time being.

[trinidefender]

The way you are looking at a wing...

I feel like we're having a bit of a communication breakdown here, because I'm saying things, and then you're repeating them back to me almost as if I haven't said them at all.

In any case, I've definitely filled this thread with enough of my rambling for the time being.

The way I interpret what you have been saying is that the slots reduce drag and reduce downforce as well. The point I am making is that they reduce drag but at the same time, maybe also keep the same level of downforce being produced.

[ringo]

About their monkey seat..
Why not have another one above as well?

They should look into doing that.

[hollus]

I would thing that the vortexes do not get a realistic chance to form before the air has exited the end plate area, by which point the wing profiles no longer exists. The end plates are much longer than the wing. That would negate the benefit of reducing the vortex strength.

[trinidefender]

I would thing that the vortexes do not get a realistic chance to form before the air has exited the end plate area, by which point the wing profiles no longer exists. The end plates are much longer than the wing. That would negate the benefit of reducing the vortex strength.

By that logic vortices would not form on aircraft wings either but actually that is where they were discovered. There are pictures floating around that in certain situations show the vortices flowing off of the edge of the rear wings. It does not matter how long the endplate is, the wing still causes vortices to form. All teams can do is try to minimise them.

[bhall]

I would thing that the vortexes do not get a realistic chance to form before the air has exited the end plate area, by which point the wing profiles no longer exists. The end plates are much longer than the wing. That would negate the benefit of reducing the vortex strength.

The omission of end plate slots above the wing increases pressure such that it amounts to an effective increase in size.

They've gone from this...



...to this...



That means more downforce. But, it also means stronger vorticity. Enter: the new slots...

EDIT: Hey, shelly, I can see now how we may have been talking past each other here. Lost in this, except for in the very beginning, is the central tenant of the whole idea: the new wing will actually increase downforce. That's why the slots above the wing are now gone. More pressure above the wing is more downforce. The new slots below the wing are but an attempt to mitigate the inherent increase in drag that will result.

[shelly]

I think a little bit different on this subject: basic point is that in F1 you do not just to minimize tip vortices, but you try to use them - for downforce.
We see an example of this on the footplate of every front wing: there is a small arched section below which a vortex tube flows.
Also we see in front wings like in the picture I posted that the multi-element section have slots also on the sides to help the flow - that's why i stressed the fact that on rb10 rwthe slots are palced in correspondance with the trailing edge of teh triple element tip section

So the tip is the zone where the local wing load is higher.
It is differnt from airplanes, more similar to fighters that use lex or delta wings, or to mav that use zimmermann wings: you use the vortex to produce more downforce at the tip.

Bout high pressure and low pressure: on a high pressure zone you cannot get a cp greater than 1 , but on the low pressure suction peak you can go as low as -4 (or more): so the hypotesis that makes more sense to me is that there is an aggressive profile on rb10 rear wing, with strong suction, and the slots hep the wing sustain the pressure recovery.

I see also positive effects of such an arrengement in yaw, again to get more downforce.

I do not thing drag reduction is the main driver for this design choice; I may be wrong of course

[ringo]

vortices are in fact not desirable. It's probably the most used word in any aero discussion.
For aero efficiency you want as less vortices as possible, especially on a rear wing.
The only exception is if you have a low energy area that could use some kinetic energy, like behind a wheel or a barge board or behind a sidepod.
On the rear wing, most of the slits you see are there to break up vortices or prevent them from forming. Vortices actually reduce aero efficiency and reduce top speeds.
Those holes we see on the new wing may be someting to do with DRS efficiency.

[Lycoming]

I would thing that the vortexes do not get a realistic chance to form before the air has exited the end plate area, by which point the wing profiles no longer exists. The end plates are much longer than the wing. That would negate the benefit of reducing the vortex strength.

By that logic vortices would not form on aircraft wings either but actually that is where they were discovered. There are pictures floating around that in certain situations show the vortices flowing off of the edge of the rear wings. It does not matter how long the endplate is, the wing still causes vortices to form. All teams can do is try to minimise them.

From wikipedia:



Generally, vortices don't develop a distinct structure until a little distance behind the wing, but they do affect flow over the wing at the tips. I know this example has no endplate, but you get the idea.

There is nevertheless a benefit to reducing vortex strength. Energy in that swirling mass of air is taken away from the car, energy which could be used to make the car go faster. Just because the vortex doesn't develop a readily visibly apparent structure until well aft of the wing does not mean it doesn't have a detrimental effect on vehicle performance.

vortices are in fact not desirable.

I'm not sure that applies 100% of the time. For sure on airplanes and on the rear wing, if you could eliminate them entirely, you would. But on the front wing, you may still choose to produce them because the net benefit downstream may outweight the penalty to front wing performance. Or it may not. I can't really tell you. But yes, the majority of the time, they are not desirable. They make use of them when they can because they're going to be there anyways.

Subsequently,

in F1 you do not just to minimize tip vortices, but you try to use them - for downforce.

I would say that you try to minimize vortices unless they can be used to make more downforce. This certainly is not the case for the vortices formed by the rear wing.