Red Bull's Rake and Suspension Set Up

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Webber2011
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Red Bull's Rake and Suspension Set Up

Post by Webber2011 » Thu Jan 05, 2017 1:04 am

Hey there guys.

I've taken the liberty of starting this thread mainly in the hope to learn more about it from you all.

I get the general principle of running a high rake angle that squats down at speed, but this interests me a great deal, so I'd love to see what everyone has to say about it.

Maybe one of you aero guys could go into detail about how it works, and fill my little brain with stuff that will take me days to decipher :D

Take it away........................

Pierce89
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Re: Red Bull's Rake and Suspension Set Up

Post by Pierce89 » Thu Jan 05, 2017 9:43 pm

As an educated aero guy I could somewhat describe what I expect the rear flow structures to do when they drop the a$$ but even as soon to graduate engineer all I can say about the hydraulics is that I think that heave displacement stores energy in a hydraulic accumulator that's activated in different ways through different valves along the travel which use the energy stored in the accumulator to move the spring seat of the heave unit basically controlling ride height.

There, is that clear as mud?
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godlameroso
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Re: Red Bull's Rake and Suspension Set Up

Post by godlameroso » Thu Jan 05, 2017 10:25 pm

The spring seat as in the spring pre-load changes? So maybe as heave force is applied the preload increases, and decreases as heave force is reduced? Thereby maintaining a specific axle height? There would have to be massive hydraulic rebound control. Probably why the units are so bulky even by F1 standards.
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thisisatest
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Re: Red Bull's Rake and Suspension Set Up

Post by thisisatest » Thu Jan 05, 2017 11:07 pm

I just posted my idea of what Red Bull might be up to in the general 1017 suspension forum. I'll just repost it here since it probably makes more sense to be here:

The Red Bull has another third element in crosswise action relative to the heave spring. It is actuated only in roll, and is stationary in heave.
My idea is that the heave element has a mechanical (or hydraulic) way of building up pressure and increasing front ride height (or lowering rear height). When there is enough roll, the other element releases the build up.
In this manner, the longer the straight, the flatter the car ends up for greater top speed. You also have greater front height during the main braking point. In the corners, the car car reverts to a high downforce angle.

So... What do you think?

Webber2011
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Re: Red Bull's Rake and Suspension Set Up

Post by Webber2011 » Fri Jan 06, 2017 4:39 am

Pierce89 wrote:As an educated aero guy I could somewhat describe what I expect the rear flow structures to do when they drop the a$$ but even as soon to graduate engineer all I can say about the hydraulics is that I think that heave displacement stores energy in a hydraulic accumulator that's activated in different ways through different valves along the travel which use the energy stored in the accumulator to move the spring seat of the heave unit basically controlling ride height.

There, is that clear as mud?
Great stuff mate, yep it's clear as mud :lol:

I think I understand everything you are saying but have a question.

I thought they were maybe using hydraulic pressure in a damper of some sort, to extend or reduce the travel of the spring.
But you think they actually use it to change the seating of the spring ?

Pierce89
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Re: Red Bull's Rake and Suspension Set Up

Post by Pierce89 » Fri Jan 06, 2017 7:32 am

Webber2011 wrote:
Pierce89 wrote:As an educated aero guy I could somewhat describe what I expect the rear flow structures to do when they drop the a$$ but even as soon to graduate engineer all I can say about the hydraulics is that I think that heave displacement stores energy in a hydraulic accumulator that's activated in different ways through different valves along the travel which use the energy stored in the accumulator to move the spring seat of the heave unit basically controlling ride height.

There, is that clear as mud?
Great stuff mate, yep it's clear as mud :lol:

I think I understand everything you are saying but have a question.

I thought they were maybe using hydraulic pressure in a damper of some sort, to extend or reduce the travel of the spring.
But you think they actually use it to change the seating of the spring ?
The Ferrari letter mentions a moving spring seat, which IMHO would mean raising or lowering ride height that way rather than the hydraulic force acting through damper itself. As I mentioned though I am in NO way sure.
“To be able to actually make something is awfully nice”
Bruce McLaren on building his first McLaren racecars, 1970

“I've got to be careful what I say, but possibly to probably Juan would have had a bigger go”
Sir Frank Williams after the 2003 Canadian GP, where Ralf hesitated to pass brother M. Schumacher

Vyssion
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Re: Red Bull's Rake and Suspension Set Up

Post by Vyssion » Fri Jan 06, 2017 1:38 pm

I was intrigued with the whole Ferrari vs. Mercedes+RedBull thing and being an aerodynamicist myself, did a quick googling to see if I could find something on what it was that they were arguing over. Check our this article: Nivomat Shock Absorbers
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Pierce89
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Re: Red Bull's Rake and Suspension Set Up

Post by Pierce89 » Fri Jan 06, 2017 3:47 pm

Vyssion wrote:I was intrigued with the whole Ferrari vs. Mercedes+RedBull thing and being an aerodynamicist myself, did a quick googling to see if I could find something on what it was that they were arguing over. Check our this article: Nivomat Shock Absorbers
Yeah that article combined with the Ferrari letter is what I used to flesh out my "description".
“To be able to actually make something is awfully nice”
Bruce McLaren on building his first McLaren racecars, 1970

“I've got to be careful what I say, but possibly to probably Juan would have had a bigger go”
Sir Frank Williams after the 2003 Canadian GP, where Ralf hesitated to pass brother M. Schumacher

DaveW
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Re: Red Bull's Rake and Suspension Set Up

Post by DaveW » Sat Jan 07, 2017 11:53 am

In my view, the reason this and similar solutions have been developed is to control the ride height (hence aero), whilst also looking after the tyres (not abusing the tyres with silly spring rates). Successively banning them all has needlessly exposed Pirelli (& they really do need looking after).

Again in my view, the solution in not new. The principle has been used for several years to prop up road vehicles. Banning it will simply make F1 even less interesting.

BTW, The author, or possibly Ferrari, got the reference wrong. I believe that the relevant clause is now 3.16, not 3.15.

henry
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Re: Red Bull's Rake and Suspension Set Up

Post by henry » Sat Jan 07, 2017 1:13 pm

I think the relevant clause is 3:14 Aerodynamic influence.

3:16 deals with bodywork flexibility.
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DaveW
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Re: Red Bull's Rake and Suspension Set Up

Post by DaveW » Sat Jan 07, 2017 5:51 pm

You could be correct, but neither, in my opinion, actually outlaws "moveable aerodynamic devices".

Arguably, the solution they are discussing will control the aerodynamic surfaces rather better than the simple spring/damper suspension.

PlatinumZealot
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Re: Red Bull's Rake and Suspension Set Up

Post by PlatinumZealot » Sun Jan 08, 2017 3:49 am

This type of accumultor suspensions has been discussed in this forum before. I think some road cars had it in the past. Even knowing that, the inner workings of this suspnion is something worth exploring.

From what i gather, the moveable spring seat that ferrari mentioned is the same spring seat of the heave spring . It sounds to be mounted on one end of a haudraulic cylinder which in turn is connected to two accumulators. The accumulators gather energy from pitch and roll movements of the car to compress nitrogen gas. Then there is an unmentioned mystery pair of mechanical brains that use this energy to control the ride height.
The mechanical brains front and rear make the system basically like the Fric suspension except it is two independent systems.

So how does it gain a similar effect without physically connecting front and rear? Well, all the rear has to do is know what the front of the car is doing and vice versa.
There is no physical pipework connecting either end, but there is something that already does this. The chassis.

I imagine the suspension system knows the attitude of the chassis and it knows the acceleration and speed of the car. With this the engineers tune the car even throughout the corners. There is a complex array of mechanical relays and stwitches in the system. Basically a passive mechanical computer. These relays are triggered by small mechanical sensors (catches, weights and gyroscopes) that detect the attitude of the car and if all the stars align.. Say.. You set the system to jack the rear up when deceleration is 3g AND roll is greater than 1 degree to the left.. The coresponding relays will open the valve and release the pressure stored up. I imagine there are limiters on the system too.
Also as soon as a phase is finished and the roll decreases... Another set of sensors open up another set of valves and the energy is released into the reservoir.

Note that you can only use wheel and car movements to feed this brain. So to know the car speed a pitot tube cannot be used. The pitch of the car in combination with spring compression roll and acceleration are used. Remember at higher speeds the force is higher on the suspension. The acceration is a bit lower. A mechanical brain can meaure these.
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DaveW
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Re: Red Bull's Rake and Suspension Set Up

Post by DaveW » Sun Jan 08, 2017 9:35 am

Forgive me, PlatinumZealot, but if Ferrari shared your thoughts, it's small wonder they protested...

That's not to say your analysis is incorrect, but I think that you might explore the Nivomat design. Alternatively several patents exist (see, for example US 2002/0148692 A1) that achieve an acceptable result using hardware built into the damper... and no explicit transducers.

Webber2011
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Re: Red Bull's Rake and Suspension Set Up

Post by Webber2011 » Sun Jan 08, 2017 1:03 pm

Great stuff guys.
As I said when I started this, my intention is to learn.

I've had a good read of the Nivomat design thanks to the links provided.
That seems to me to be a reasonable explanation of what they are up to, but F1 is usually a little more complex.

I can see it being fairly simple to use sensors to tell the system when to release or provide pressure, but seriously, how quick could that happen ?
Is it as fast as the active suspension we saw in the 90's?
Is it something that they can only take full advantage of on a straight, or is the response time so fast that they can use it in corners as well ?

thisisatest
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Re: Red Bull's Rake and Suspension Set Up

Post by thisisatest » Tue Jan 10, 2017 12:08 am

Wow. I know I was pretty vague in my idea, but still I was right and I'm patting myself on the back about it :D
The hydraulic actuator acting as an energy accumulator in the roll of the car moments so mainly when changing direction and cornering. In subsequent instants, when ended sections where the car "rocked" (on the straights so), the hydraulic accumulator ceding energy to the system by acting on the rocker of the suspension and then the real third element that was going to change the ' from the car's ride height. This meant a raising of the front part of the car a few millimeters with consequent lowering of the rear axle. That dynamic rake of which we had already after the Grand Prix at Silverstone.
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