A CFD Investigation of Aerodynamic Effects of Wheel Center Geometry on Brake Cooling 2017-01-1537

Improving brake cooling has commanded substantial research in the automotive sector, as safety remains paramount in vehicles of which brakes are a crucial component. To prevent problems like brake fade and brake judder, heat dissipation should be maximized from the brakes to limit increasing temperatures. This research is a CFD investigation into the impact of existing wheel center designs on brake cooling through increased cross flow through the wheel. The new study brings together the complete wheel and disc geometries in a single CFD study and directly measures the effect on brake cooling, by implementing more accurately modeled boundary conditions like moving ground to replicate real conditions correctly. It also quantifies the improvement in the cooling rate of the brake disc with a change in wheel design, unlike previous studies. The axial flow discharge was found to be increased to 0.47 m3/min for the suggested design in comparison to 0.04 m3/min for traditional design. The increased axial flow enhances the velocity of flow over the brake disc leading to quicker dissipation of heat from turbulent eddies in the outer boundary layer. The brake disc exhibited approximately 33%-50% higher Heat Transfer Coefficient with the change in wheel center geometry. It is suggested that the implementation of a similar design is highly beneficial for improved brake cooling, and could bring a positive impact on the exploitation of wheel designs for the same, which currently are more tuned towards aesthetics than performance.