Red Bull RB18

A place to discuss the characteristics of the cars in Formula One, both current as well as historical. Laptimes, driver worshipping and team chatter does not belong here.
AR3-GP
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Re: Red Bull RB18

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ringo wrote:
Fri Sep 16, 2022 1:32 am
I am not so sold on the wider pods and rear wheel drag reduction idea. The sidepods dont project outward enough to seem to have an influence on the air hitting the rear tyres.
I would like to see a CFD study with some numbers on this for me to be comfortable accepting it.
The claim is the sidepod manipulate the front wheel wake to reduce drag. But i think they are too far downstream of the front wheels to have much influence. The frong wheels have a low pressure are behind them, with a lot of eddies and turbulence. In the older formula the barge boards would push the air flowing along the fuselage and underneath it to the side, which would indirectly pull along the messy air behind the front wheel. If this is to improve flow to and around the sidepods itself I am not sure.
But to say the wider pods which are even furth from the front wheels are reducing drag on the rears..it would need to be demonstrated.
Vanja 66 did a rudimentary CFD analysis that showed the influence of sidepods on the pressure distribution on the face of the rear tire. Off topic so it's best if you go here for further questioning: viewtopic.php?p=1035377#p1035377

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Vanja #66
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Re: Red Bull RB18

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AR3-GP wrote:
Thu Sep 15, 2022 7:58 pm
I do believe Red Bull have replicated some kind of diffuser stalling system. You say the floor doesn't cause drag, but it does. The floor has turning vanes at the front. Those introduce flow losses. The floor and diffuser have aggressive volume expansions which introduce losses. The skin friction of the entire floor introduces losses. The floor edge itself is a source of losses which increase as the floor power increases.
You misunderstood me, I didn't say it doesn't produce drag, I said floor is still the lowest drag element on the car (in mid-high wing downforce configurations, of course). Those turning vanes cause drag, yes, but things are even more complex than that, there are multiple surfaces one behind another, pressure is projected on both sides etc. Overall, mid-high downforce wings still cause more drag.

AR3-GP wrote:
Thu Sep 15, 2022 7:58 pm
If you were to kill the the diffuser, you would depower the entire floor. Velocity everywhere is reduced. The losses due to boundary layers, expansions, and turning vanes are reduced are they not? You suggested previously that the RB18 philosophy is that of a flat floor race car w/ a diffuser accelerating the air over flat floor. Using the diffuser to power the floor. Is this not the clue as to the behavior of the car and why stalling the diffuser would reduce drag?

This mechanism was described as the trick for Mercedes last season as well. RB seem to be using the DRS as the on off switch whereas last season Mercedes had to faff about with minimum cornering speeds to tune their system properly (it's like the W13 system targeted the non-DRS straights whereas RB's system targets the DRS straights).

Red Bull would be able to predict the ride height and pitch angle of the car given the fixed front wing load, and the on-off loads of the rear wing at high speed. As you say, the RB18 only exhibits this jet mode when the DRS is open. When the DRS is closed, Ferrari matches them in the straights.
It's a very different situation this year with diffuser design vs last year. The only thing is that diffuser still exists, though some teams made sure it exists in name only. RB is not one of those, but it's still very far from last year.

When you have a flat floor and diffuser, there are strong relations between diffuser ramp angle and ride height - bigger angle requires more ride height. Then, you can introduce 40-50mm rake in the rear and make the whole thing even crazier. With soft suspension you can drop the rear on straights, lower overall frontal area, lower RW AOA and ride height. These factors combined can lead to diffuser stall (to some extent) especially since it was very outwashing design. You also had bunch of vanes in diffuser as well, which also generate less drag when stalled, so there were more benefits than there would've been this year.

Contrary to that, this year you have a design that requires very stable and stiff suspension, to prevent floor chocking mid-corner, you can't introduce so much rake (only RB does, and it's less than 20mm by the looks of it), you can't afford diffuser stall since floor contributes even more to overall downforce than the last 40 years and losing this downforce mid-corner is a one-way ticket to barriers. On top of all that, you have insanely strong beam wings which drive the diffuser extra hard and basically leave no room for any kind of stall.

So I don't see what kind of physics mechanism would be at play here to introduce diffuser stall at high-speed without the risk of it happening mid-corner. As for DRS-triggered stall, I still don't see the mechanism, beam wings are fixed and those are more important to the floor than rear wings. If you have an idea for diffuser stall that works around what I just wrote, please share, that would be a juicy one. :D
And they call it a stall. A STALL!

#Aerogimli
#DwarvesAreNaturalSprinters
#BlessYouLaddie

Henk_v
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Re: Red Bull RB18

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Could it be less exotic and that the RB car aerodynamics are simply robust? Having a car that keeps its downforce while banking, curbing and braking is more predictable to drive and thus can be driven much nearer to the limit. That would mean that its not specificaly the concept itself thats better, its just that one can use its potential more.

Andi76
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Re: Red Bull RB18

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vorticism wrote:
Sat Sep 10, 2022 2:34 pm
https://www.racefans.net/wp-content/upl ... 7-31-5.jpg

If the continuous front arm is acting as a transverse leaf spring then it would allow them to make the pullrods slightly thinner.
Rory Byrne was the first to use s monolithic wishbone. I was told by s Ferrari engineer that indeed acted like a spring. So i think that continous front arm acting like you said is reasonable.
Zynerji wrote:
Thu Sep 15, 2022 4:36 pm
Why did the 93 Williams have a button to "pop up" the diffuser on the straights?
If memory serves, the FW15 had a button to lower the rear of the car to reduce the AoA of the rearwing for less drag and higher Topspeed, not a "Pop-Up" Button.

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Zynerji
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Re: Red Bull RB18

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Andi76 wrote:
Sat Sep 24, 2022 11:21 am
vorticism wrote:
Sat Sep 10, 2022 2:34 pm
https://www.racefans.net/wp-content/upl ... 7-31-5.jpg

If the continuous front arm is acting as a transverse leaf spring then it would allow them to make the pullrods slightly thinner.
Rory Byrne was the first to use s monolithic wishbone. I was told by s Ferrari engineer that indeed acted like a spring. So i think that continous front arm acting like you said is reasonable.
Zynerji wrote:
Thu Sep 15, 2022 4:36 pm
Why did the 93 Williams have a button to "pop up" the diffuser on the straights?
If memory serves, the FW15 had a button to lower the rear of the car to reduce the AoA of the rearwing for less drag and higher Topspeed, not a "Pop-Up" Button.
Their was a replay that I watched years ago that the commentary clearly stated that Hill had a button to raise the rear ride-height and break the diffusor effect to drop drag on the straight. I'll see if I can find it again...

https://www.goodwood.com/grr/event-cove ... F1-winner/

"During the race the driver could also access a ‘Push to Pass’ system which caused the rear suspension to raise the rear of the car, reducing drag from the diffuser and simultaneously loosening the rev limiter to provide an extra 300rpm."


So, the real question should be:

Did RBR find a way to keep the 2021 rear-squat-at-speed mechanic with the new rules, and is now running it in reverse by raising-at-speed to drop diffuser drag? It would answer lots of q's if true. Specifically, why they don't porpoise at high speed, and have less drag down the straights.

AR3-GP
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Re: Red Bull RB18

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Zynerji wrote:
Sat Sep 24, 2022 1:51 pm
Andi76 wrote:
Sat Sep 24, 2022 11:21 am
vorticism wrote:
Sat Sep 10, 2022 2:34 pm
https://www.racefans.net/wp-content/upl ... 7-31-5.jpg

If the continuous front arm is acting as a transverse leaf spring then it would allow them to make the pullrods slightly thinner.
Rory Byrne was the first to use s monolithic wishbone. I was told by s Ferrari engineer that indeed acted like a spring. So i think that continous front arm acting like you said is reasonable.
Zynerji wrote:
Thu Sep 15, 2022 4:36 pm
Why did the 93 Williams have a button to "pop up" the diffuser on the straights?
If memory serves, the FW15 had a button to lower the rear of the car to reduce the AoA of the rearwing for less drag and higher Topspeed, not a "Pop-Up" Button.
Their was a replay that I watched years ago that the commentary clearly stated that Hill had a button to raise the rear ride-height and break the diffusor effect to drop drag on the straight. I'll see if I can find it again...

https://www.goodwood.com/grr/event-cove ... F1-winner/

"During the race the driver could also access a ‘Push to Pass’ system which caused the rear suspension to raise the rear of the car, reducing drag from the diffuser and simultaneously loosening the rev limiter to provide an extra 300rpm."


So, the real question should be:

Did RBR find a way to keep the 2021 rear-squat-at-speed mechanic with the new rules, and is now running it in reverse by raising-at-speed to drop diffuser drag? It would answer lots of q's if true. Specifically, why they don't porpoise at high speed, and have less drag down the straights.
My hunch is the opposite. Something to do with the DRS triggering stall. We may not understand the mechanism currently but it's so blatant in the telemetry. Teams have had all season to try trivial solutions like a larger DRS flap and no one has achieved the same effect.

zeffman
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Re: Red Bull RB18

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If teams have (allegedly) been experimenting with sprung planks to reduce plank wear on measured regions, what's to stop them experimenting with sprung diffuser exits?

AR3-GP
AR3-GP
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Re: Red Bull RB18

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zeffman wrote:
Sat Sep 24, 2022 5:10 pm
If teams have (allegedly) been experimenting with sprung planks to reduce plank wear on measured regions, what's to stop them experimenting with sprung diffuser exits?
There are probably stiffness test.

zeffman
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Re: Red Bull RB18

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Yes, I would have thought so too.

But, before this year, I would also have assumed that there were also tests that stopped any areas of the plank being flexible.

Could RB be exploiting a passively blown rear wing actuated (as a secondary effect, for legality reasons) when DRS is enabled? It would take a long time to tune this perfectly and they did seem to have a lot of incidents where their DRS was causing them lots of last-minute issues before the quali/races started.

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organic
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Re: Red Bull RB18

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zeffman wrote:
Sun Sep 25, 2022 6:43 am
Yes, I would have thought so too.

But, before this year, I would also have assumed that there were also tests that stopped any areas of the plank being flexible.

Could RB be exploiting a passively blown rear wing actuated (as a secondary effect, for legality reasons) when DRS is enabled? It would take a long time to tune this perfectly and they did seem to have a lot of incidents where their DRS was causing them lots of last-minute issues before the quali/races started.
They had the same DRS problems last year and I don't remember the RB16B having a particularly large delta v with DRS open/closed

To me it seems more likely the Drs problems are associated with weight saving and caused by structural weakness/flexing beyond expectations. It only started being seen once budget cap started, so maybe linked to parts having a longer lifetime than historically. The team first experienced DRS issues in 2022 directly after Max received a weight saving update at Barcelona.

More evidence for the DRS problems being unrelated to their advantage in that respect is that McLaren, who have frankly shocking DRS efficiency, are also running into these problems:



Of course, perhaps I'm wrong: the problems could simply be related to fine tuning of DRS and that's why it's cropped up in 2021 and 22

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Bandit1216
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Re: Red Bull RB18

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I have a theory. Maybe it's already suggested. Ifso, I'm sorry.

I have a feeling RB dedicates more of the floor, relative to the rest of the designs, to feed the area next to the diffuser. To feed the brake duct "sort of diffusers" aside of the diffuser, attached to the wheels. The skids to are used to feed these area's and at the same time stall them when the ride height drops. Hard to explain what I mean

https://files.catbox.moe/rnutbe.webp
But just suppose it weren't hypothetical.

AR3-GP
AR3-GP
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Re: Red Bull RB18

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Article worthy of note in relation to theories about RB18 and straighline speed: https://www.autosport.com/f1/news/willi ... 3/5297353/
Both Williams drivers went off in British Grand Prix qualifying after the new wing created an aerodynamic stall at the diffuser when DRS was opened and then shut again.

Cassius
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Re: Red Bull RB18

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Edax wrote:
Mon Sep 26, 2022 11:37 pm
Just_a_fan wrote:
Mon Sep 26, 2022 10:04 pm
Big Tea wrote:
Sun Sep 25, 2022 12:31 pm

Was there not at one time a driver operated wing angle, sort of DRS? Could it be this? not sure when it was in use and thought it was front wing that 'moved'
Front wing was driver selectable in 2009. The driver could increase the front wing angle to reduce understeer when following another car. Didn't last long, IIRC, as it wasn't that good.
I might be wrong but I recollect that was introduced together with the mandatory slick tire compound change during the race to help the drivers cope with tyre variation.
Can we go back discussing the RB18 please.

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jagunx51
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Re: Red Bull RB18

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https://www.motorsport.com/f1/news/red- ... /10375323/

The key F1 design decisions that allowed Red Bull to dominate 2022
Red Bull’s RB18 has emerged as the best of the 2022 Formula 1 cars, especially on Sundays, and could arguably be the finest the Milton Keynes-based squad has ever produced.
Image
............!!!!

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organic
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Re: Red Bull RB18

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Image

Some reflective material applied to the brake drum of the RB18 this weekend. Not surprising that some modifications are made in this area since it's so demanding on brakes