PhillipM wrote: ↑
Sun Nov 11, 2018 12:56 pm
Do I need to? If they needed more heat transfer there they'd make it solid, let the aluminium (with it's orders of magnitude higher heat conduction) move the heat, and give the brake rotor mounts more surface area to transmit more heat through the hub.
It'd be massively more effective.
You are assuming that after the air passes through the very hot hub where the brakes are mounted, it will be cooler than the rim which is warmed by the tyres worked by the track?
Why do you suppose that after passing through the parts holding those 1000 degree brakes.. that same air wont draw enough heat to be at a higher temperature than the relatively cool rim already in contact with 150mph air on its external surfaces?
Heat flows from high to low temperature. If that air already after already passing through the very hot hob, which is hotter (which i suspect) than the wheel rim already in contact with nice cool air on its outer surface, heat will flow into the rim from that hot air.
Those tiny little holes on that space seem suspect to provide any significant air flow to drive heat off a wheel rim.
I could be wrong after someone from Mercedes or another team comes out and explains this, but just looking at it from a basic heat flow point of view, that cooling air has to be cooler than the rim if heat is to leave the rim. And it's difficult to see this being the case, unless this air has been carefully insulated from the brake area as it passes through the holes in the hub. As is I i stand correct, but i would need to see a proper thermodynamic explanation.