Red Bull RB18

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Stu
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Re: Red Bull RB18

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johnny comelately wrote:
Fri Jun 17, 2022 2:30 pm
henry wrote:
Fri Jun 17, 2022 2:21 pm
Looking at this mechanism I have a thought about how it might be configured to help with porpoising and high speed braking. Newey has said that he was particularly involved in the suspension, maybe he included this area?

The load response of this mechanism is covered by 3.15.6 in the regulations.
At all times during the test, the load at a given deflection must exceed the load given by a straight-line graph defined by connecting the following coordinates in order: (0 mm, 0 N) (1 mm, 0 N) (5 mm, 4000N) (25mm, 6000N). This must be the case whether the deflection is increasing, decreasing, or held constant. The test will have no more than a maximum load of 8000N or a maximum deflection of 15mm (whichever is reached first) unless specifically requested by the FIA to investigate behaviour above these limits.
The load deflection relationship must be strictly monotonic with both increasing and decreasing deflection
Two things I note. Firstly it is quite stiff, the forces are quite high for quite small movements of this section of the floor. Secondly, the regs are concerned about hysteresis, the bolded part. However there is no mention of how quickly the load is applied or removed.

If the car starts to porpoise, perhaps it hits a bump the road, load on this part of the floor will increase, and then the aero load goes down and the car is pushed up with a force which is the difference between aero load and the sum of the load from the suspension springs, including the tyres, and the floor mechanism. If the floor has hysteresis, as the car starts to lift the floor’s contribution to the upward force, and hence movement will decrease. If the hysteresis is high enough it will lose contact with the road, the load it provides goes to zero and a gap will open allowing air flow under the plank. This would reduce the vigorous and amplitude of porpoising.

The porpoising frequency is around 6hz. I doubt very much that the measurement mechanism applies loads at anything like that rate. The spring elements, Belleville washers are notorious for hysteresis and who knows what damping mechanism there is in the strut.

In high speed braking there is a load transfer to the front of the car, for a 5g stop around 3500N. This will compress the front suspension and tyres and likely load up the front of the floor. This might reduce the braking force and stability. With hysteresis, as soon as the speed reduces the front of the car will rise and the contact force of the floor to the road will drop, perhaps to zero, increasing braking force, improving stability and possibly allowing greater air flow to the floor.

For both these potential mechanisms running the car with a small amount of rake would be needed. I don’t think it’s possible to easily judge rake on these cars given the configuration and flexibility of the floor edge.

This is not necessarily exclusive to RB18, other cars have mechanisms here but the RB one is easy to observe.
The damping is the key point there, it should stop any tendency of hysteresis.
Are you sure about 6 hz?
I cannot find the item number in the regs, but I’m certain that damping is not allowed (others run variations on a leaf-spring), so maybe the hysteresis is beneficial from a damping perspective?
The more that I learn, the more I appreciate how much more there is to know….

AR3-GP
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Re: Red Bull RB18

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Stu wrote:
Sat Jun 18, 2022 6:10 pm
johnny comelately wrote:
Fri Jun 17, 2022 2:30 pm
henry wrote:
Fri Jun 17, 2022 2:21 pm


Looking at this mechanism I have a thought about how it might be configured to help with porpoising and high speed braking. Newey has said that he was particularly involved in the suspension, maybe he included this area?

The load response of this mechanism is covered by 3.15.6 in the regulations.



Two things I note. Firstly it is quite stiff, the forces are quite high for quite small movements of this section of the floor. Secondly, the regs are concerned about hysteresis, the bolded part. However there is no mention of how quickly the load is applied or removed.

If the car starts to porpoise, perhaps it hits a bump the road, load on this part of the floor will increase, and then the aero load goes down and the car is pushed up with a force which is the difference between aero load and the sum of the load from the suspension springs, including the tyres, and the floor mechanism. If the floor has hysteresis, as the car starts to lift the floor’s contribution to the upward force, and hence movement will decrease. If the hysteresis is high enough it will lose contact with the road, the load it provides goes to zero and a gap will open allowing air flow under the plank. This would reduce the vigorous and amplitude of porpoising.

The porpoising frequency is around 6hz. I doubt very much that the measurement mechanism applies loads at anything like that rate. The spring elements, Belleville washers are notorious for hysteresis and who knows what damping mechanism there is in the strut.

In high speed braking there is a load transfer to the front of the car, for a 5g stop around 3500N. This will compress the front suspension and tyres and likely load up the front of the floor. This might reduce the braking force and stability. With hysteresis, as soon as the speed reduces the front of the car will rise and the contact force of the floor to the road will drop, perhaps to zero, increasing braking force, improving stability and possibly allowing greater air flow to the floor.

For both these potential mechanisms running the car with a small amount of rake would be needed. I don’t think it’s possible to easily judge rake on these cars given the configuration and flexibility of the floor edge.

This is not necessarily exclusive to RB18, other cars have mechanisms here but the RB one is easy to observe.
The damping is the key point there, it should stop any tendency of hysteresis.
Are you sure about 6 hz?
I cannot find the item number in the regs, but I’m certain that damping is not allowed (others run variations on a leaf-spring), so maybe the hysteresis is beneficial from a damping perspective?
The car still has damping properties at the 4 corners. So in a way, the floor is damped. What's interesting is the belleville allows them to tune the rebound of the chassis to floor strikes. Maybe this could be tuned to work well with the corner dampers?

SirBastianVettel
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Re: Red Bull RB18

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In this video Toto says Red Bull is a massive outlier in ride height and started putting rake in the car again. I personally don’t see it, but am very curious what you all think about it.

SirBastianVettel
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Re: Red Bull RB18

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Nice photo of the rake on the RB18 in Canada.

Image

Apologies for not crediting the photographer, I don't know who made this photo.

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organic
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Re: Red Bull RB18

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SirBastianVettel wrote:
Tue Jun 21, 2022 12:21 pm
Nice photo of the rake on the RB18 in Canada.

https://i.ibb.co/6YQyPXD/IMG-20220621-062314.jpg

Apologies for not crediting the photographer, I don't know who made this photo.
Yes I'd say that's some rake

TimW
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Re: Red Bull RB18

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organic wrote:
Tue Jun 21, 2022 12:22 pm
SirBastianVettel wrote:
Tue Jun 21, 2022 12:21 pm
Nice photo of the rake on the RB18 in Canada.

https://i.ibb.co/6YQyPXD/IMG-20220621-062314.jpg

Apologies for not crediting the photographer, I don't know who made this photo.
Yes I'd say that's some rake
I have some doubt. The floor edge at the Rauch logo is pretty high above the tarmac.
The plank is lower, but the plank is not visible further back due to the perspective. So the rake may also appear to be there due to the plank coming into view.

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henry
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Re: Red Bull RB18

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jagunx51 wrote:
Tue May 17, 2022 12:43 am
internal floor stay ( source : https://www.motorsport.com/f1/news/the- ... /10305288/ )

Image
Following on from thoughts on the front floor suspension I wonder if this component, red arrow, is any more than an adjustment device?

I think the stay and beam are positioned around the location of the “skate”. Might the tube be a spring or damper helping to manage the contact of the skate with the ground? Again I might think it would be helpful if after a bump in the road raised the skate, and reduced ride height, it might be useful to keep the rear floor raised to re-establish airflow through the diffuser.

It’s clear that Red Bull have put a lot of effort into managing the sensitivity of load with ride height to reduce the potential for porpoising.
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Henk_v
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Re: Red Bull RB18

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I am sure its just something to tune the stay length.

What interests me is the angle. Any force up or down will translate into a much larger force in the sideways horizontal plane. Thus force will try to compress or split the floor. As the floor is split by the keel at this point, the floor must be quite weak in counteracting these forces, resulting in large floor deformation. If this is played right, one can make these deformations advantageous and even design a floor thst will not deform if tested, but will deform if the Total aero load is applied.

A regular floor will deform more or less like a beam, the tip being the lowest if the load is applied, hence the floor edge will move the most under aero load. Using clever geometry, one could device a floor that deforms differently to suit the needs. Designing a floor in which the floor edge raises under aero load is conceivable

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diffuser
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Re: Red Bull RB18

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TimW wrote:
Tue Jun 21, 2022 3:52 pm
organic wrote:
Tue Jun 21, 2022 12:22 pm
SirBastianVettel wrote:
Tue Jun 21, 2022 12:21 pm
Nice photo of the rake on the RB18 in Canada.

https://i.ibb.co/6YQyPXD/IMG-20220621-062314.jpg

Apologies for not crediting the photographer, I don't know who made this photo.
Yes I'd say that's some rake
I have some doubt. The floor edge at the Rauch logo is pretty high above the tarmac.
The plank is lower, but the plank is not visible further back due to the perspective. So the rake may also appear to be there due to the plank coming into view.
It looks like it but it wouldn't make sense as the closer the floor is to the ground the more DF it creates...

AR3-GP
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Re: Red Bull RB18

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diffuser wrote:
Thu Jun 23, 2022 6:36 pm
TimW wrote:
Tue Jun 21, 2022 3:52 pm
organic wrote:
Tue Jun 21, 2022 12:22 pm


Yes I'd say that's some rake
I have some doubt. The floor edge at the Rauch logo is pretty high above the tarmac.
The plank is lower, but the plank is not visible further back due to the perspective. So the rake may also appear to be there due to the plank coming into view.
It looks like it but it wouldn't make sense as the closer the floor is to the ground the more DF it creates...
but porpoising.

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diffuser
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Re: Red Bull RB18

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AR3-GP wrote:
Fri Jun 24, 2022 2:50 am
diffuser wrote:
Thu Jun 23, 2022 6:36 pm
TimW wrote:
Tue Jun 21, 2022 3:52 pm


I have some doubt. The floor edge at the Rauch logo is pretty high above the tarmac.
The plank is lower, but the plank is not visible further back due to the perspective. So the rake may also appear to be there due to the plank coming into view.
It looks like it but it wouldn't make sense as the closer the floor is to the ground the more DF it creates...
but porpoising.
Rake isn't gonna prevent porpoising!

Remember, the rake disappeared at higher speeds. You controlled when it disappears with different hardness springs. It always
disappeared and that is when the porpoising happens.

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PlatinumZealot
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Re: Red Bull RB18

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Having rake means that they have mastered the vortices around and under the floor to maintain low pressure conditions and add energy where needed.
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diffuser
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Re: Red Bull RB18

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PlatinumZealot wrote:
Fri Jun 24, 2022 3:13 am
Having rake means that they have mastered the vortices around and under the floor to maintain low pressure conditions and add energy where needed.
Since they don't have rake in any other pictures except one, exiting the garage. They have only mastered the airflow exiting their garage. Great thinking there Z!


Here's a pic exiting the hair pin in Montreal.....what 40 KPH ?
Image


Here's another one from a better angle...

Image


One more that catches the RB18 at the slowest part of the hairpin.

Image

hkbruin
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Re: Red Bull RB18

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Looks like there is a bit of rake in this side shot from their Silverstone shakedown. Sorry I don’t know how to embed image links via mobile.

https://images.app.goo.gl/gZxBNwmw9wjC2CpG8

Image

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Holm86
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Re: Red Bull RB18

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hkbruin wrote:
Fri Jun 24, 2022 4:32 am
Looks like there is a bit of rake in this side shot from their Silverstone shakedown. Sorry I don’t know how to embed image links via mobile.

https://images.app.goo.gl/gZxBNwmw9wjC2CpG8

https://images.app.goo.gl/gZxBNwmw9wjC2CpG8
To me it doesn't look like rake, just high ride height all over, which I guess would be pretty normal for a shakedown