Design, Set-up and Validation of an Aerodynamic Bench for Wheel Corner Flow Investigation in Vented Brake Discs Testing

Brake disc cooling is strongly affected by the aerodynamic condition surrounding the system and especially by the flow at the ventilation channels inlet. Aero-thermal performance of brake discs are usually tested using a dyno bench in which the aerodynamic field is not representative of the one in the wheel corner of car vehicles. The purpose of this study is to design a dyno bench configuration, called aero-dynamic bench, whose airflow replicates the cooling distribution seen in a vehicle wheel corner. A carbon-ceramic brake disc (CCM) and an aluminum caliper of a sports car are considered for the design. The work can be summarized into three steps. The first step consists of a computational fluid dynamic (CFD) analysis of the dyno bench. The second step involves the realization of the new dyno bench facility starting from the standard one and calibrating the air supply systems. Third, the flow field at the outlet of the ventilation channels is measured by means of Laser Doppler Anemometry (LDA) as well as hot-wire anemometry (HWA). Experimental results are qualitatively in line with CFD analysis and reveal that installing the brake disc in the wheel corner results in a vented air mass flowrate reduction. Moreover, the presence of forced convection, compared with the disc auto-ventilation condition, makes the flow exiting the disc channels more uniform as well as with a reduced turbulence intensity level.