Brake Ducts, Tire Cooling, and beyond

[ringo]

PCMare illegal for cooling.
Agreed there is fancy airflow through the braking system.
The cool air that redbull claimed to have seen was coming out of the exhaust duct at the rear of the inside of the wheel.
The duct seems to be split in two.
So they raised alarm about this not being possible without water cooling.
What it may have been is just bypassed air. Just as a Jet turbine engine bypasses air flow for increased thrust. Ovbiously for different reasons here. But cooler air coming out can only be from a portion of the air not coming into contact with the hot surfaces in the brakes.

[Stea1th]

High pressure air flow combined with zirconia-based ceramic coating within the carbon fiber shell.

The issue is you can’t cool on air alone, it doesnt work well enough due to radiant heat still transferring to the tire

[atanatizante]

In this video, a motorsport engineer specializing in chassis and carbon structures gives his opinion on the hypothesis of using PCM in the brakes of the MCL39 (from minute 3:00, English translation with CC):

- Basically, he says that it's all about thermal inertia and weight, which are the biggest issues here ...

[RGAEDA]

We haven't seen the backside of the inner shell or the middle shell.

1. Could there be a direct hot air exit duct on the unseen side of the inner shell with a short path?
2. If this setup is possible, can the volume of hot air in the inner shell be cleared quickly?
3. Does it become easy to manage the heat inside if hot air travels less distance and spends less time traversing exit ducts?

[autodoctor911]

What is limiting the amount of braking force applied to the rear wheels via mgu-k application of regenerative braking??? Have anyone been using shunts to bleed off extra current that the battery can't absorb? Also, what about just throwing a bunch of excess current to the mguh under braking? Once the rear tires and brakes are up to temperature, you could reduce the chance of overheating by using more mguk braking, which is liquid cooled and away from the tires
If you can't get rid of all the rear braking energy to the battery, would it not be possible to just feed it to the turbo, and or some big resistors (air or liquid

[Tommy Cookers]

What is limiting the amount of braking force applied to the rear wheels via mgu-k application of regenerative braking???

IIRC the rules cap MGUK torque to 200 Nm at the crankshaft (when 120 kW action is desired but crankshaft rpm is low)
this cap might be interpreted as allowing more than the nominal 120 kW driving of the generator (when rpm is high)

[chrisc90]

Aren’t the MGU h/K decided by engine manufacturer too? So Mercedes would need the same setup??

[FNTC]

[organic]

Any summary of this video?

[vorticism]

Layer of fluid in the cake tin. Flappy metal bits. Thermoelectric cooling but no suggestion of implementation. New to me: some kind of coolant loop tied in with "the drink," as a Ferrari race engineer might put it.

Like other pundits they are saying that cooling parts around the brakes would befall "liquid cooling of the brakes is prohibited," but imo this is not the case. The brakes are the disc, pads, brake fluid, lines, and the calipers, not the upright, the ducts, wheel bodywork, etc. Regardless, we have numerous photos of the wheel bodywork in states of disassembly and within there has been no indication of unusual hydraulic or electrical connections.

[AR3-GP]

The theories are interesting, but the way that Noble tries to "disqualify" them by way of "liquid cooling of brakes is prohibited" is very superficial. First, Mclaren aren't trying to cool the brakes. They are trying to cool the wheel rims. Therefore "liquid cooling of brakes is prohibited" should not apply. Wheel rims are not brakes.

I doubt that Mclaren have done anything in the video, but it's not clear that something from the video would be forbidden by the FIA. We wouldn't know unless these exact solutions were sent by Red Bull to the FIA, and the FIA said in no uncertain terms that it was not allowed.

[FNTC]

As I understand the video, these are the different theories that Red Bull have queried FIA about, and FIA saying almost all of them would be illegal (different types of liquid cooling, drinks bottle routing, etc), except for using peltier devices (but they would consider outlawing them for 2026 if used this year).

From video transcript:

the correspondence is fascinating as it offers us the first proper insight from a competitor about theories on what McLaren could have been up to and what the FIA thinks about some of these design ideas the race has seen a copy of this technical directive which includes a host of questions from Red Bull about design ideas and procedures relating to tire cooling plus some responses from the FIA on what it thinks is and isn't allowed

a design could incorporate having such Peltier devices fitted somewhere within the assembly that could then be used to cool things down or even heat things up with there being no moving parts on a Peltier device. it conforms to the technical rules that require everything to be rigidly attached to the upright. the FIA's response on the idea of using such a solid state thermoelect electric cooler is intriguing. the FIA's answer says "We believe that the use of Peltier devices for cooling in this area is not covered by the technical regulations but would not consider it favorably and would seek to specifically exclude it for 2026

[AR3-GP]

Peltier devices seem unlikely. It would require a lot of electricity.

[AR3-GP]

Then again peltier devices could be operated from a switch on the steering wheel...heating and cooling something on demand. I'm just not certain that there's much power density in peltier devices.

[vorticism]

This might spur Zack Brown to place a minifridge next to his tire water bottle on the pit wall.