Red Bull RB8 Renault

[raymondu999]

Yeah I've read that a long while ago, but it still doesn't say that

they tunnelled the exhaust gasses to the beam wing.

[wesley123]

it doesnt. What gilgen is trying to say is that the exhaust and it's position will draw air through the tunnel and help draw exhaust air out of the cooling hole.

While the effect is true, and was used in 2010 for the blown diffusers, I personally think the exhaust is too far away from the cooling exhaust and where this dirty air and air from the tunnel mix. So I dont think hte exhaust has much effect of drawing air through the tunnel

[Cam]

it doesnt. What gilgen is trying to say is that the exhaust and it's position will draw air through the tunnel and help draw exhaust air out of the cooling hole.

While the effect is true, and was used in 2010 for the blown diffusers, I personally think the exhaust is too far away from the cooling exhaust and where this dirty air and air from the tunnel mix. So I dont think hte exhaust has much effect of drawing air through the tunnel

I don't think that's what gilgen was saying:

Tunnelled exhaust gases? They tunnelled EXHAUST gases? Are you sure?

Yes. the coanda exhausts onto the rear floor and the airflow around the base of the sidepod, helps draw some hot gasses through the tunnels. Go back on photos of testing, and see where the heat sensors are placed.

The Red Bull does not (to my understanding) flow any exhaust gas through the tunnel (well, none intentionally anyway). Please correct me here if I'm wrong, but I thought the ramp fed the exhaust gases to the diffuser and the tunnel took air from the side pods to the starter motor?

[gilgen]

I was told this by a person with some knowledge of this, and i got it slightly wrong. What is happening is that the tunnels take the sidepod airflow away from the diffuser and to the starter hole, this allows the exhaust gasses to attach themselves to the rear bodywork, aft of the tunnels, so ensuring that it can be utilised on the full width of the beam wing.
If the tunnels were not taking the air from the lower sidepods, then it would push the gasses outwards, providing less effect on the beam wing.
I do trust the source,but cannot explain it as succintly as the informant.

[raymondu999]

Yup. That I agree with. The exhausts flow along the ramped bodywork by Coanda effect, and the tunnel helps to manage the crossover between exhaust flow and free flow so that they don't interfere with one another.

[Nando]

Beam wing? Surely it directs most of it down to the far ends of the diffuser?

I thought that was the whole point of the tunnel, to keep the exhaust gases stuck onto the bodywork all the way down to the rear tire inside.

[Jackles-UK]

I agree with everything Gilgen says except where the exhaust gases are directed.

Surely the whole coanda exhaust train of thought was to 'force' for lack of a better word the exhaust gases to the floor just inside the inside shoulder of the rear tyre sealing the diffuser edges similar to that of the 2011 EBDs? This was why Mercs late attempt at a coanda system was plagued by rear tyre over-heating problems.

Plus, throwing their DDRS into the equation, if the exhaust gases were firing at the beam wing wouldn't the high pressure restrict the downflow of air through the RW endplates? I was under the impression the low pressure zone on the underside of the beam wing effectively "sucked" air down from the turbulent high pressure area on the edges of the RW main planes, block that off and it'll have nowhere to go and just cause a bit of a mess!

[Cam]

You'd think that Newey wants to regain what he lost in the RB7. So let's have a look at the RB7. You can see the exhausts are pointed to blow right beside the inside of the tyre. This 'seals' the diffuser - as is my understanding.



So the ramp does the same thing, it tries to move the exhaust gasses to the same spot (red arrows) while allowing air (blue arrows) through by going under the exhausts to the desired spot at the diffuser/ starter motor hole. (This view is the underside of the RB7, but the principle is what I'm attempting to demonstrate). If I have this wrong, please let me know.

[CHT]

Newey mentioned two significant upgrade for RB8, one in Valencia and the other in Singapore. What were those upgrade?

"We came out with a car which had flashes of pace," Newey told Servus TV. "Sebastian won in Bahrain, Mark [Webber] won in Monaco. But we didn't have the level of consistency we wanted, and as an engineer that was very frustrating because the truth is we didn't properly understand the car and what was happening.

"We made a step at Valencia and then we made a further step in Singapore and that gave us that purple patch where Sebastian won four on the trot which really set up the Championship challenge."

[wesley123]

They came up with a new version of the exhaust ramp solution in Valencia, and after that refined the ramp in signapore and added DDRS

[raymondu999]

Reworked rear suspension at Singapore too.

[Crucial_Xtreme]

I think this is the best analysis of what RB's exhaust ramp, tunnel & DDRS system do:

Is there a connection between Red Bull's new double-DRS system, and their unique 'underpass' duct?

To recall, the underpass is a means of separating the 'coke-bottle' flow along the flank of the sidepod, from the exhaust-flow, sweeping down from the top of the sidepod. The coke-bottle flow feeds the starter-motor slot and the top surface of the diffuser's trailing edge, while the exhaust jet partially seals the side of the diffuser and increases the flow over the rear brake-duct assembly.

The underpass is fed by the flow along the flanks of the sidepods, which in turn is fed by the front-wing wake. By connecting the flow along the flanks of the sidepods to the low pressure area under the beam wing, the underpass not only assists with rear downforce, but also pulls the air faster over the front-wing.

Red Bull's double-DRS system purportedly stalls the central section of the beam wing, (although Craig Scarborough suggests that it is the tips of the beam-wing which are being stalled, in order to reduce the wing-tip vortex drag).

The central part of the beam wing is the section which is pulling the air out of the underpass. Thus, if the beam wing stalls, then the underpass stalls, the flow along the flanks of the sidepods weakens, and front-wing downforce and drag are reduced.

The image above here illustrates how the front-wing streamlines on a generic open-wheeled race-car are the same streamlines which pass along the flanks of the sidepods, and thence between the rear wheels, (although there is no sidepod undercut or beam wing in this illustrative case, courtesy of the 2012 University of Southampton Racecar Aerodynamics MSc Group Design Project).

Red Bull introduced a smaller underpass inlet for the Korean Grand Prix, and if the double-DRS really does stall the centre of the beam wing, it would certainly make sense to change the underpass as well. Autosport's Mark Hughes comments in his Korean Grand Prix report that the changes to the sidepod area gave "more downforce and more diffuser stall."

One can speculate then, that Red Bull's double-DRS is a system which reduces front-wing drag as well as helping to stall the beam wing and diffuser.

McCabism

[ringo]

Speculation indeed.
It doesn't really add up. Especially the front wing wake part.
The modern wings flow diffeent to that image in the link. The sidepod flow is also very different since the barge boards by the cockpit are present.
As for beam wing stalling, i'm not sure what the tips are. the beam wing has enplates, and the vorteces coming of the beam wing is minimal compared to the rear wing. The flow is very uniform.
Secondly stalling the outermost parts is very dificult.

Do we have any images of the DDRS system from redbull?

[gilgen]

Speculation indeed.
It doesn't really add up. Especially the front wing wake part.
The modern wings flow diffeent to that image in the link. The sidepod flow is also very different since the barge boards by the cockpit are present.
As for beam wing stalling, i'm not sure what the tips are. the beam wing has enplates, and the vorteces coming of the beam wing is minimal compared to the rear wing. The flow is very uniform.
Secondly stalling the outermost parts is very dificult.

Do we have any images of the DDRS system from redbull?

There have been a number on this thread. Also check F1fanatic. (sorry, dont know how to re post the articles!)

[sof1jou]

Hello at all

I' m new to this forum and i have a question please , where can i get somthing lik this?? (technical draw) for the Red Bull RB8

http://i49.servimg.com/u/f49/14/79/55/26/lotus-12.jpg

i will be very thankful for help