Red Bull RB8 - vented brake/wheel assembly 13 May 2012
Brake ducts are increasingly being designed and used as aero devices and Red Bull have even built their suspension uprights and wheel rims to work in conjunction with the ducts, so as to better direct hot airflow around the outside of the tyres. In this drawing you can see the central hub has a series of small holes. Air is drawn through the brake duct and drum, passing the disc and caliper, and is then expelled through these holes which align with similar openings in the wheel rim. This reduces disruptive waste airflow inboard of the wheel and also reduces the transfer of heat between the rim and the tyre.