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Thermal performance of a brake system is one of the key attributes in a new vehicle development process. Adequate brake cooling characteristics are part of the vehicle performance and safety requirements. The design of a new brake system, however, can be a complex task from a thermal engineering perspective, particularly because of complex interactions between the brake component and the rest of the vehicle. Frequently, the vehicle integration issues are the most serious challenges for brake engineers. There are considerations on how much heat should be dissipated from a single and/or consecutive braking events vs. how much cooling can be provided to the brake corner. Design issues such as where to direct the cooling air to how much flexibility is allowed while complying with other requirements from the studio and aero teams. For a brake engineer, the priority is to maximize cooling to the brake corner and prevent system failure.

Successive braking of the vehicle, hereinafter referred as brake duty cycle, can elevate the temperature of the brake disc to a very high level. Such high temperatures reached in brake discs can lead to vaporization of the brake fluid if the vehicle is at rest after the brake duty cycle. Excessive temperature operation of the brake disc can also lead to thermal cracks, judder, brake fade, wear and reduce braking effectiveness. Simulation tools can be used to predict the excessive temperature reached during successive braking event. After visualizing the complex flow field over the brake system and analyzing the heat transfer from brake system, simulations can be employed at the early design stage to optimize the design for more airflow over brake discs thus reducing the high temperatures and associated brake fade. In this paper, a CFD model of the vehicle with brake system is coupled with a thermal solver at braking and acceleration velocities.