A Combined Experimental and Numerical Analysis on the Aerodynamics of a Carbon-Ceramic Brake Disc

Composite ceramic brake discs are made of ceramic material reinforced with carbon fibers and offer exceptional advantages that translate directly into higher vehicle performance. In the case of an electric vehicle, it could increase the range of the vehicle, and in the case of conventional internal combustion engine vehicles, it means lower fuel consumption (and consequently lower CO2 emissions). These discs are typically characterized by complex internal geometries, further complicated by the presence of drilling holes on both friction surfaces. To estimate the aerothermal performance of these discs, and for the thermal management of the vehicle, a reliable model for predicting the air flowing across the disc channels is needed. In this study, a real carbon-ceramic brake disc with drilling holes was investigated in a dedicated test rig simulating the wheel corner flow conditions experimentally using the particle image velocimetry technique and numerically. The simulation was performed using the moving reference frame (MRF) approach and the experimental data were used to validate the numerical model. The results show that drilling holes contribute to about 13% of the inlet mass flow and more than 86% of the air driven into the brake disc comes from the main inlet of the disc. Moreover, the numerical results are in an agreement with experimental data, supporting MRF approach as a suitable model for the analysis of complex flows in complicated geometries.