Red Bull RB12 TAG-Heuer

[Silent Storm]

Somers has lost it. I remember his tweets on 2017 tyre test on Redbull and Ferrari where he thought Ferrari did their diffuser and side skirts from an aesthetic point of view and the rear wing was not shaped in a right way

[SR71]

SR71, if you read his post rather than assuming he's having a go at your beloved RedBull, you'd see he was pointing out that the article is wrong. The article's author obviously doesn't understand what he's writing about.

Again, keep ignoring the bold text.

It's counter-intuitive as described but the term OVERLOAD means a lot in this instance. Try considering that.

[SR71]

At this point I started laughing, "The rub comes from being able to find a speed threshold whereby you’re effectively switching off the rear wing. This happens when the car's rake is reduced: as the load builds with speed, the car is forced toward the ground, which in-turn rotates the wing and overloads it, stalling flow, both reducing downforce and drag."

Reducing rake actually reduces angle of attack on the rear wing very slightly and will moves the wing even further away from the stall region of its profile.

You should call Red Bull up and tell them they have no idea what they are doing when it comes to Aero.

Also, just ignore the bold text because it has nothing to do with anything.

He's not saying Red Bull messed up; the point you missed out on is that Matt Somerfield has the wrong impression here, which I agree with Trinidefender.

I mean this does not hold any truth for instance:

Furthermore, the nose-down attitude of the car puts the front wing further into ground effect, improving not only its performance but the components downstream, as downforce is increased but not to the detriment of additional drag.

Uhm, except drag is added here. Running more into ground effect will increase your underwing vortex, increasing drag. It is more efficient, yes, but you are still creating additional drag.

I read it as him meaning this is more efficient downforce than running the wing high off the ground. Pretty sure you know he meant that as well.

Are you saying the RB front wing would produce less drag if the rake was removed and the ground effect minimized?

No rake + high wing = X amount of DF

You're saying Rake + same wing + ground effect = X + more drag?

If you're not saying that then he's correct.

The point I was making was about how changing the AOA of RB'S rear wing profile could overload it and stall it - it might seam counterintuitive that flattening the car is what's causing this but to throw it out the window because you don't like the author makes you even sillier than him.

Love,
SR71

[SR71]

i figured anyone knocking Matt for being wrong would be able to understand how a profile can be very effective when in the raked position and lose it's efficacy at high speed with an angle change.

seems pretty obvious to me.

illustrated below is a rough diagram showing the same profile can change dramatically with only a few degrees of movement, blue illustrating a flattened high speed position (with stalled zones), pink in a low speed high rake position.... If anyone could get something like this to work it would be Red Bull.



We have how many pages of people crying about teams not copying each other then an article comes out highlighting something unique RB is doing aero wise and everyone slams it?

Maybe we should go back to flinging purses about who should copy who...

[bhall II]

Love,
SR71

Why am I frequently left with the impression that you're no stranger to being dropped on your head?

At any rate, the problem with any "stalling" mechanism that's initiated by the reduced ride height caused by aero loading is that the "stall" will release the load and return the car to its normal ride height.

[SR71]

Love,
SR71

Why am I frequently left with the impression that you're no stranger to being dropped on your head?

At any rate, the problem with any "stalling" mechanism that's initiated by the reduced ride height caused by aero loading is that the "stall" will release the load and return the car to its normal ride height.

Really? You know for a fact that Red Bull have no other mechanism in place to offset the released load? suspension? Floor? Nothing?

You're saying it's completely impossible for the wing to stall itself out from being overloaded while the car is increasing in speed and allowing the floor to continue to work to pull the car down? That there are no other aero surfaces on the car that can keep it flat at high speed?

You must be one of those 'creative' engineers.

By creative I mean look in the tool box and if no solution exist it must be impossible.

[bhall II]

You're saying it's completely impossible for the wing to stall itself out from being overloaded while the car is increasing in speed and allowing the floor to continue to work to pull the car down? That there are no other aero surfaces on the car that can keep it flat at high speed?

If there's an aerodynamic surface keeping the car "flat" at high speed, then there's an aerodynamic surface producing downforce at high speed. And if there's an aerodynamic surface producing downforce at high speed, then there's an aerodynamic surface creating drag at high speed. That would sorta defeat the purpose of the whole thing, yanno?

Don't think that just because something is mooted in an ill-considered article that it must be true. RB12 is simply a good car. No magic necessary.

[bill shoe]

Apologies for interrupting the argument, but I think the GPS data is very cool to compare. The Merc chassis is holding its own against RB, maybe even a bit better in the slow stuff. The Merc powertrain obviously better. The RB mantra about "we have the best chassis but are let down by our engine" is a bit weak. At best they are equal on chassis. Yes I know, only one qualy session so a small sample size.

The cars have huge longitudinal performance, both accel and braking. They are never really going a steady-state velocity, rather they are always braking hard or accelerating hard. I would not have guessed this was the case.

[SR71]

You're saying it's completely impossible for the wing to stall itself out from being overloaded while the car is increasing in speed and allowing the floor to continue to work to pull the car down? That there are no other aero surfaces on the car that can keep it flat at high speed?

If there's an aerodynamic surface keeping the car "flat" at high speed, then there's an aerodynamic surface producing downforce at high speed. And if there's an aerodynamic surface producing downforce at high speed, then there's an aerodynamic surface creating drag at high speed. That would sorta defeat the purpose of the whole thing, yanno?

Don't think that just because something is mooted in an ill-considered article that it must be true. RB12 is simply a good car. No magic necessary.

Nope... not if the combination of those other surfaces produced less drag than the rear wing would, which could have been stalled out at a speed much lower than needed on the straights for a NET reduction in drag.

These teams spend millions for hundreths of seconds and you're seriously even arguing that that Red Bull, the dominate team when it comes to rake and adjusting surfaces at different speeds with respect to the rake wouldnt try something as simple as a passive stall of their rear wing? Especially when faced against a much more powerful engine on the straights?

Love,
SR71

[bill shoe]

http://www.auto-motor-und-sport.de/img/ams/logo.svg

OK, old guy does physics. (Coughs, rolls up sleeves, gets slide-rule out).

The hardest accel appears to occur between points 9 and 10, basically around the left-hander near the word "Arena". Squinting at the chart I get the Merc with these two points:

• 150 kph at 1140 m
  200 kph at 1200 m

So velocity goes from 41.7 m/s to 55.6 m/s in a distance of 60 m.

Works out to average accel of 11.3 m/s^2 (1.15 G). Sobering to realize my old Toyota Camry would literally not accelerate that hard if it fell off a cliff.

If car is 705 kg, this is 7940 Newtons of accel force.

At an average speed of 175 kph this works out to 520 hp, again this is accel power only and does not include the power to overcome tire resistance and air resistance.

But still an honest 520 hp applied to accelerate the mass.

[trinidefender]

i figured anyone knocking Matt for being wrong would be able to understand how a profile can be very effective when in the raked position and lose it's efficacy at high speed with an angle change.

seems pretty obvious to me.

illustrated below is a rough diagram showing the same profile can change dramatically with only a few degrees of movement, blue illustrating a flattened high speed position (with stalled zones), pink in a low speed high rake position.... If anyone could get something like this to work it would be Red Bull.

https://postimg.org/image/pelxtcyhb/

We have how many pages of people crying about teams not copying each other then an article comes out highlighting something unique RB is doing aero wise and everyone slams it?

Maybe we should go back to flinging purses about who should copy who...

The problem with that illustration is that it's just that. A 5 year old could have drawn that and it would have the same amount of credibility.

I really don't mean to sound patronising (although I probably am) but it is a simple fact that reducing the angle of attack on a wing moves it further away from its stall region. I.e. If you looked at a graph where one axis was speed and another was angle of attack and past a certain line depicted on the graph the wing would stall. You would see that reducing angle of attack moves the wing away from that stall line.

Now a reduction in angle of attack caused by the rear squatting at high speed will reduce its downforce and by extension its associated induced drag (slightly, not by any huge amount but probably enough for a team like redbull to care about and model). However this relationship is fairly linear, therefore the car will not end up bouncing up and down as the flow stalls, reattaches and repeats as stated by Bhall.

It seems to me that you are looking at this in a very subjective light. Try to be a little more objective in your thinking. Nobody here is criticising redbull, we are criticising the silly statements in the article.

Also as Bhall stated, the redbull car doesn't have to have magic ideas to be fast, it is simply a very well engineered car. Good engineering and ideas is a bit like forming an opinion. Anybody can have an opinion in the same way that anybody can come up with an idea. However what separates good engineering is having the ability to take an idea and change it, work with it, leave it open to interpretation and devote time and energy to making the idea better. Same thing with opinions, the best ones are the ones that evolve and aren't stuck in one place based on ignorance.

"with respect to the rake wouldnt try something as simple as a passive stall of their rear wing?" there is your problem, you are so stuck believing that the wing will stall be reducing its angle of attack. It doesn't.

Sorry I realise I have now gone way off topic. I'll leave this post by simply stating that redbull have a very well engineered car, that is its magic in itself.

[FPV GTHO]

Is there any proof of how much the rear end is compressing at speed?

[SR71]

i figured anyone knocking Matt for being wrong would be able to understand how a profile can be very effective when in the raked position and lose it's efficacy at high speed with an angle change.

seems pretty obvious to me.

illustrated below is a rough diagram showing the same profile can change dramatically with only a few degrees of movement, blue illustrating a flattened high speed position (with stalled zones), pink in a low speed high rake position.... If anyone could get something like this to work it would be Red Bull.

https://postimg.org/image/pelxtcyhb/

We have how many pages of people crying about teams not copying each other then an article comes out highlighting something unique RB is doing aero wise and everyone slams it?

Maybe we should go back to flinging purses about who should copy who...

The problem with that illustration is that it's just that. A 5 year old could have drawn that and it would have the same amount of credibility.

I really don't mean to sound patronising (although I probably am) but it is a simple fact that reducing the angle of attack on a wing moves it further away from its stall region. I.e. If you looked at a graph where one axis was speed and another was angle of attack and past a certain line depicted on the graph the wing would stall. You would see that reducing angle of attack moves the wing away from that stall line.

Now a reduction in angle of attack caused by the rear squatting at high speed will reduce its downforce and by extension its associated induced drag (slightly, not by any huge amount but probably enough for a team like redbull to care about and model). However this relationship is fairly linear, therefore the car will not end up bouncing up and down as the flow stalls, reattaches and repeats as stated by Bhall.

It seems to me that you are looking at this in a very subjective light. Try to be a little more objective in your thinking. Nobody here is criticising redbull, we are criticising the silly statements in the article.

Also as Bhall stated, the redbull car doesn't have to have magic ideas to be fast, it is simply a very well engineered car. Good engineering and ideas is a bit like forming an opinion. Anybody can have an opinion in the same way that anybody can come up with an idea. However what separates good engineering is having the ability to take an idea and change it, work with it, leave it open to interpretation and devote time and energy to making the idea better. Same thing with opinions, the best ones are the ones that evolve and aren't stuck in one place based on ignorance.

"with respect to the rake wouldnt try something as simple as a passive stall of their rear wing?" there is your problem, you are so stuck believing that the wing will stall be reducing its angle of attack. It doesn't.

Sorry I realise I have now gone way off topic. I'll leave this post by simply stating that redbull have a very well engineered car, that is its magic in itself.

Actually it can. Depends on what it's neutral position is with respect to rake and the actual shape of the foil.

You know none of this info, neither do i.

Maybe the problem is we are both misusing the angle of attack term.

if the specific foil + neutral position when the chassis is in max rake is on the edge of its envelop. Reducing the rake angle can stall it. This isn't debatable as not all foils are the same. This is where the 'good engineering' you speak of comes in.

Second the squatting of the chassis need not be connected to the rear wing. In fact nowhere in the article is it suggested these two actions are tied together nor have I suggested it.

The chassis squat could be a compound effect of many things mechanical and aero.

If RB has this dramatic change in rake, then wouldn't DRS effect it if it was as sensitive as you suggest? The car would be very unstable at high speed of chassis squatting was directly related to the rear wing.

It's not.

[Just_a_fan]

RB12 is simply a good car. No magic necessary.

But...but...but...Newey...genius...RedBull...Newey...genius...but...but

[Just_a_fan]

Second the squatting of the chassis need not be connected to the rear wing. In fact nowhere in the article is it suggested these two actions are tied together nor have I suggested it.

The article suggests otherwise actually

The rub comes from being able to find a speed threshold whereby you’re effectively switching off the rear wing. This happens when the car's rake is reduced: as the load builds with speed, the car is forced toward the ground, which in-turn rotates the wing and overloads it, stalling flow, both reducing downforce and drag.

Car squats at speed, rotates wing relative to flow.

Personally, I think the change in angle with rear squat is so small as to be lost in the noise. If a half-a-degree change in rake could stall the rear wing, the car would be a nightmare on a bumpy track where rake would be dynamic, in effect.