Modeling the Cooling Characteristics of a Disk Brake on an Inertia Dynamometer, Using Combined Fluid Flow and Thermal Simulation 2009-01-0861

For automotive disk brake systems, convective cooling from the rotor to surrounding airflow is an important phenomenon, impacting the rotor and friction material operating temperatures and thereby influencing friction behavior, brake pedal response, and long-term durability characteristics. Many different rotor geometries and vent patterns have been proposed in the industry, however most performance evaluation and design optimization is still done empirically through on-vehicle testing or by using a test bench such as a brake dynamometer. Existing simulations of rotor airflow performance typically do not consider the installed condition with caliper, splash shield, and knuckle [1,2], or do not combine airflow and heat transfer characteristics. This paper will present a simulation model of a disk brake assembly installed on an inertia brake dynamometer, using CFD modeling coupled with thermal loading and heat transfer analysis. Correlation with physical test is demonstrated across different heat load, rotation rate, and airflow conditions. Model validation and data visualization methods are also discussed, and future steps to improve and utilize the modeling method are proposed.