Red Bull RB8 Renault

[aral]

Rumour has it that RB will be reverting to launch exhaust position for Oz race.

According to reports, Red Bull are saying that the exhaust gasses are not going where they want them to go. With so many designers on this thread, Adrian should have a look, even though it may make him more confused!

[cliffgamerz]

Rumour has it that RB will be reverting to launch exhaust position for Oz race.

It is wise for them to return back to launch specs because of lack of running and understanding, they did not even use flowvis on that area to test it whether it is working.

[eurocentric]

So the try and hide your cards until the last moment looks like it hasn't worked this time then!

[prince]

Rumour has it that RB will be reverting to launch exhaust position for Oz race.

According to reports, Red Bull are saying that the exhaust gasses are not going where they want them to go. With so many designers on this thread, Adrian should have a look, even though it may make him more confused!

Well, when i saw so many drawings on previous pages, i was wondering if my physics knowledge is of total waste. I thought gases with enormous pressure scatter (look at W03's pic on sidepods) and not flow like fluids. At immediate exit of the exhaust, it could be linear and only a small stream might flow in the directions of drawings, but my feeling is that, not all that will go in the direction of drawings, unless covered channels lead them to. Enlighten me here with some knowledge.

Last year the exhausts were so close to diffuser, it made sense and good amount of hot gas pressure was going into diffuser and helped in generating lot of downforce. With this year's specifications, i suspect even if 10% of last year's pressure could be diverted to diffuser. Factor into all this, outside air pressure (i bet it would be very different from windtunnel) and disturbance that could come when there is a car in front. So essentially, the exhaust gases would not really flow the way you intend to when the distance between diffuser and exhaust outlet is so far.

When i saw the design immediately near to exhaust exit, on all cars, i was wondering, are they expecting fluid to come out, which they are diverting downside?

[kilcoo316]

And also, it would be tuned to dump the great majority of the downforce when going just faster than the fastest turn.

That would be a bad, bad idea.


Fancy losing much of your diffuser downforce half way through 130R when 'tuning' it?


You'll absolutely wreck the car and lose at least 1 session.

[Mr.G]

... With this year's specifications, i suspect even if 10% of last year's pressure could be diverted to diffuser.

I know this isn't exactly the same but..

“... the original solution is the one that gives the most. I think we can claw back, at best, at least 25% of the downforce we had last year, even if we need to see what that costs us in fuel consumption and corner turn-in stability.”

[f1motta]

Check this pictures guys - stripped RB8 http://www.f1talks.pl/2012/03/06/za-nie ... red-bulla/

[bonjon1979]

Check this pictures guys - stripped RB8 http://www.f1talks.pl/2012/03/06/za-nie ... red-bulla/

Good job they went to all that trouble with the umbrellas etc...

[Shakeman]

So the try and hide your cards until the last moment looks like it hasn't worked this time then!

I don't think they were hiding their cards til the last minute.

This smacks of a response to other teams particularly McLaren and Ferrari and being behind the curve on this particular area. I don't believe any top flight F1 team would leave the proving of such a complex system to the last minute because there' too many factors that could trip them up i.e. weather and accidents.

Unless of course, they've begun to believe their own hype!

[kilcoo316]

In general, the idea of 'stalling' a diffuser is non-sensical.


I believe it was the "experts" in the media that came up with this hair-brained idea.


A diffuser has virtually no induced drag - the only significant drag that scales with downforce is pressure drag - and with a diffuser ramp angle being... what? 10 degrees? your drag is the sin of that - i.e. ~17.4% of all diffuser pressure forces will be acting backward*... or you will have a drag component equal to ~17.1% of the downforce of your diffuser [cos(10) * sin(10)].

So... based on the premise of a CL of -3, at 150 mph, an F1 car generates approx 1050 kg of downforce, if a quarter of that comes from the diffuser, and the diffuser drag is approximately 17% of the diffuser downforce, then 45 kg or 440 N of drag comes from the diffuser... or about 13% of the total car drag is coming from the diffuser (assuming Cd = 1).


Now... aside from there being far bigger fish to fry, there is the issue of ensuring diffuser stall only occurs when you want it - not when going over a kerb, not when the suspension bottoms out or jumps over a bump, or when the driver is on/off throttle. The complexities of this balanced against the marginal gains would lead to the only logical conclusion - the teams do not try and stall the diffusers!



*assuming attached flow etc etc etc.

[Rikhart]

Check this pictures guys - stripped RB8 http://www.f1talks.pl/2012/03/06/za-nie ... red-bulla/

Good job they went to all that trouble with the umbrellas etc...

Awesome, thanks! Any idea which day they were taken? Is this the last version chassis?

[shelly]

Attached flow is one thing, laminar flow another.

Really? Where does the distinction lie?

This internet page has some useful information:

http://www.av8n.com/how/htm/spins.html

Mods feel free to branch this out into another thread if you feel it's better

+1 maybe more focussed threads on aero would help, since there is always a lot of recurring confusion on aero in the car threads.

[CHT]

Check this pictures guys - stripped RB8 http://www.f1talks.pl/2012/03/06/za-nie ... red-bulla/

Good job they went to all that trouble with the umbrellas etc...

Awesome, thanks! Any idea which day they were taken? Is this the last version chassis?

From the look of the rear suspension arm, i think its RB8 V1.0

[shelly]

@kilkoo: I think theta teams were for real toying with stalling of the diffuser under tha rule set till 2008.

The diffuser has some induced drag, and influences the flow around the car - stalling it ould help with top speed. Tricky to get the flow to reattach under braking, though, as you have to develop tricks which are not that straightforward as carving a small v at the center of your rear flap.

[CHT]

So the try and hide your cards until the last moment looks like it hasn't worked this time then!

I don't think they were hiding their cards til the last minute.

This smacks of a response to other teams particularly McLaren and Ferrari and being behind the curve on this particular area. I don't believe any top flight F1 team would leave the proving of such a complex system to the last minute because there' too many factors that could trip them up i.e. weather and accidents.

Unless of course, they've begun to believe their own hype!

Totally. and I am expecting RBR to turn up at Melbourne with the RB8 V1.0 instead of the V2.0 which they tested on the last 2 days at Barcelona.