Red Bull RB8 Renault

[tok-tokkie]

^^^
If it is creating downforce on the suspension arm it is the optimum place to do it for traction - hold the wheel onto the ground. It looks like it is doing that and also turning the plume slightly upwards towards the bottom of the beam wing.

[Shrieker]

Well if you come to think of it, you would try and pile all the downforce you could on the suspension arm, but it has a small surface area compared to the beam wing and no angle to speak of; that's why I wondered

[aral]

Have a look at the brake duct winglet, shown six pages back. This is shaped carbonfibre. The exhaust is blowing down on these winglets, and downforce from these would be far greater than blowing on the suspension arms.

[Owen.C93]

There was a bit of a rumour that they were using the exhaust over the wishbones to heat the rims and tyres which would explain why McLaren said they could turn on their tyres so quickly.

I mean if they thought they couldn't get any useful DF from the new exhaust regs then surely that's the next best thing.

Of course that kinda makes Renault's engine guys talking about how they still manage to blow off throttle a bit of a curious comment wouldn't it.

[Crucial_Xtreme]

Have a look at the brake duct winglet, shown six pages back. This is shaped carbonfibre. The exhaust is blowing down on these winglets, and downforce from these would be far greater than blowing on the suspension arms.

The RB8 has almost the same brake ducts as the RB7, but I'm not really seeing the exhaust gasses being directed into the winglets. Looks like it's hitting the beam wing and directly under it. Below is a small but relevant image in relation to RB8 exhaust gasses.



edit: I see you might be saying it would could be more advantages to blowing winglets rather than what they're currently doing. Not sure if that's what you mean though.

[Timstr]

Why do people think that blowing hot air onto a tiny brake-duct fin or on a suspension member will in itself create any meaningful downforce? None I think.

I think blowing in the area between the rear wheel and gearbox is to clean up and accelerate the airflow over the top of the diffuser so that air is extracted faster from underneath the diffuser. And that is the actual downforce creation.

[Nickel]

Based on what do you think no meaningful down force is created? If air flows under the element faster than over it, down force is created, end of story.

[PhillipM]

Why do people think that blowing hot air onto a tiny brake-duct fin or on a suspension member will in itself create any meaningful downforce? None I think.

Well, one, I disagree with 'tiny' they're massive multi-element wings on there these days, and two, downforce generated straight onto the unsprung mass is more beneficial than downforce fed through the sprung mass.

[ringo]

Why do people think that blowing hot air onto a tiny brake-duct fin or on a suspension member will in itself create any meaningful downforce? None I think.

If you put the exhaust point blank infront of the brake fins, you'd be surprised how much downforce you'd get. The regs are what are stopping the pipes from coming anywhere close enough to blow transonic over the fins.

[flynfrog]

Based on what do you think no meaningful down force is created? If air flows under the element faster than over it, down force is created, end of story.

yes but you are missing Tims point that amount is much less than pulling more through the diffuser and beam wing area.

[Nickel]

Why do people think that blowing hot air onto a tiny brake-duct fin or on a suspension member will in itself create any meaningful downforce? None I think.
I think blowing in the area between the rear wheel and gearbox is to clean up and accelerate the airflow over the top of the diffuser so that air is extracted faster from underneath the diffuser. And that is the actual downforce creation.

yes but you are missing Tims point that amount is much less than pulling more through the diffuser and beam wing area.

I don't dispute at all the idea that energizing the flow over the top of the diffuser can help extract more air from under the floor. I have a bit of trouble with the concept that it cleans up the airflow though.

Also, I have a lot of trouble believing that a team like red bull went to the trouble of placing the upper wishbone in such a way that the exhaust flows directly under it for "no meaningful downforce" unless you're arguing that this is simply to redirect the air at the diffuser. Something tells me it doesn't redirect the air that dramatically. My interpretation of what I see on the rb8 says it acts on both wishbones and the beam wing.

Also, I think the wishbone is a good choice because it can be placed so close to the exhaust, where there is the most energy. By the time it gets to the beam wing/diffuser area, much of that energy is dissipated.

[hardingfv32]

that the exhaust flows directly under it for "no meaningful downforce" unless you're arguing that this is simply to redirect the air at the diffuser.

The control arm is aero neutral per the rules. If that is the case how do you get down-force?

Brian

[kalinka]

It's aero-neutral in headwind, but if you blow it with exhaust gases from different angle, than it becomes non-neutral. It's not an aerofoil shape, but it can deflect air/gases coming from different angles. Is it possible that the upper suspension arm ( which is colsest to exhaust ) deflects the exhaust gases to stay lower ? It looks like it could trim downward ( or at least make it almost horizontal ) the stream of gases quite a lot.

[Crucial_Xtreme]

A peek inside the letterbox

right click>view image for high res

[kalinka]

It's a quite fine mesh inside. Why it's required if the slot is only for driver cooling...maybe against insects ? Not kidding.