Red Bull RB8 Renault

[Adrian Newby]

I have made no such suggestion.

[kilcoo316]

I have made no such suggestion.

So what happens when you lose a significant amount of diffuser downforce in the middle of a turn during free practice when tuning?

As I said a couple of pages back - most likely you wreck the car and lose at least one session!

[OO7]

So it's just an ungainly bulkhead?

The reason for it's design has already been described so I won't delve into that. However I believe the area in which this structure meets the floor, is outside the location in which legal cut-outs or holes are allowed in the floor and having seen numerous pictures of the rear floor and diffuser from multiple angles, there are no exits which would confirm ducted airflow to the diffuser, other than the 'undercut underpass' we already know of.

And yet there clearly is a groove on the floor, going from where the bridge attaches, to the back. Why is that there?

I can't say that I can see a groove in the floor. I can see the way the edge of the side-pod extends far back over the rear floor. The reason for this I presume is:
1) To form and maintain an efficient exit for the airflow received by the undercut/underpass.
2) To form a barrier that encourages the exhaust that has spilled over the edge of the side-pod, to enter the outer diffuser and help form a skirt, rather than migrate inboard and blend with the undercut airflow. So basically separating the underpass airflow and spill-over exhaust gases.

[Adrian Newby]

I have made no such suggestion.

So what happens when you lose a significant amount of diffuser downforce in the middle of a turn during free practice when tuning?

As I said a couple of pages back - most likely you wreck the car and lose at least one session!

Who said it would be "actively" tuned on the track? They could just design/tune it to be faster than the highest speed corner on all of the circuits, or even each particular circuit. It wouldn't have to be as close to the cornering speed as you imply.

[OO7]

It should be mentioned that not every unknown duct or hole or airflow entrance is an F-duct or fluidic switching device. They seem to be very en-vogue in thoughts of those trying to decipher various aspects of these F1 cars.

[kilcoo316]

Who said it would be "actively" tuned on the track? They could just design/tune it to be faster than the highest speed corner on all of the circuits, or even each particular circuit. It wouldn't have to be as close to the cornering speed as you imply.

So are you back to suggesting it be tuned exclusively using CFD/wind tunnel?



As for one approach for all circuits:

“130R will be taken flat for every lap of the Grand Prix with an apex speed around 305 km/h,”

http://www.formula1.com/news/features/2 ... 11349.html

I'd also suggest that with such a high apex speed, the margin for stalling will be close to the cornering speed. The top speed at most tracks is not significantly greater than 300 kph. At 200 mph, your margin is only 7%.

[Adrian Newby]

Who said it would be "actively" tuned on the track? They could just design/tune it to be faster than the highest speed corner on all of the circuits, or even each particular circuit. It wouldn't have to be as close to the cornering speed as you imply.

So are you back to suggesting it be tuned exclusively using CFD/wind tunnel?



As for one approach for all circuits:

“130R will be taken flat for every lap of the Grand Prix with an apex speed around 305 km/h,”

http://www.formula1.com/news/features/2 ... 11349.html

I'd also suggest that with such a high apex speed, the margin for stalling will be close to the cornering speed. The top speed at most tracks is not significantly greater than 300 kph. At 200 mph, your margin is only 7%.

Well, you might not use it at Suzuka then. Or you might accept a bit slower speed at 130R for faster straight speeds, or maybe the decrease in drag will get you just enough better mileage to make one less pit stop. There are many ways to skin a cat. And remember, this is basically something for nothing. If you can use it at a circuit you do, if you can't you don't. Not that hard to understand.

[OO7]

Well, you might not use it at Suzuka then. Or you might accept a bit slower speed at 130R for faster straight speeds, or maybe the decrease in drag will get you just enough better mileage to make one less pit stop. There are many ways to skin a cat. And remember, this is basically something for nothing. If you can use it at a circuit you do, if you can't you don't. Not that hard to understand.

Where can the duct exit legally be placed, when you can't really have holes in the floor.

[kilcoo316]

@AN

Now - you know as well as I do that it is not the work of a minute to re-tune a car's aero-balance after making a pretty fundamental change to the exhaust-diffuser interaction.

(as in - its not the kind of thing easily switched on and off between different weekends - you'll have a completely different aero-map)

[horse]

I'd be amazed if there is fine control of the exhaust effect given how far forward it is. Velocity, yaw rate, cross winds - it would be impossibly complicated.

[Adrian Newby]

@AN

Now - you know as well as I do that it is not the work of a minute to re-tune a car's aero-balance after making a pretty fundamental change to the exhaust-diffuser interaction.

(as in - its not the kind of thing easily switched on and off between different weekends - you'll have a completely different aero-map)

Of course it wouldn't be done in a minute. You don't think they figure things out ahead of time? I sure wouldn't underestimate Adrian Newey like that. I personally think they might have two or three different versions for different types of tracks.

The most basic explanation I can think of to get you to understand is that it would be like the "blown rear wing" concept, where the exhaust was aimed at the wing for additional downforce, but at higher speeds the exhaust was blown more straight back where it wouldn't affect the wing as much. You don't think they would have designed in the speed at which that would happen to the best of their abilities (within the rules)? This is the same concept.

[horse]

The most basic explanation I can think of to get you to understand is that it would be like the "blown rear wing" concept, where the exhaust was aimed at the wing for additional downforce, but at higher speeds the exhaust was blown more straight back where it wouldn't affect the wing as much.

As far as I know, the exhaust blown rear wing idea is unproven and unlikely due to similar difficulties in controlling it.

[kilcoo316]

@AN

I already know what you have been saying.


But simply put; you cannot have the downforce of your front axle varying with V^2 and the downforce of your rear axle varying with V^1.8!!! (just for instance - and it wouldn't even be close to being that straightforward)


Try and balance that!


I'm not underestimating anyone, but at the same time, I'm not going to blindly ignore the complexities of what is suggested and simply say "'cos they're dead bright, they'll have no problem with it".

[Adrian Newby]

The most basic explanation I can think of to get you to understand is that it would be like the "blown rear wing" concept, where the exhaust was aimed at the wing for additional downforce, but at higher speeds the exhaust was blown more straight back where it wouldn't affect the wing as much.

As far as I know, the exhaust blown rear wing idea is unproven and unlikely due to similar difficulties in controlling it.

The effect would be much like an F-duct that only worked over a certain speed. And F-ducts seemed to work pretty well.

[horse]

The effect would be much like an F-duct that only worked over a certain speed. And F-ducts seemed to work pretty well.

It's nothing like an f-duct. You had a constant targeted flow with an f-duct that was digitally controlled by the driver, no matter the velocity of the car.

An exhaust blown rear wing depends on velocity, throttle input, cross winds, yaw rate, etc etc. If the driver had to lift off the throttle in a fast corner, he'd be stuffed.

If an f-duct type effect was possible with the diffuser I'm sure it would have happened before this year, when there was more flexibility with the exhaust positioning, rather than now when they are placed so far away.