Analysis of automotive disc brake cooling characteristics

The aim of this investigation was to study automotive disc brake cooling characteristics experimentally using a specially developed spin rig and numerically using finite element (FE) and computational fluid dynamics (CFD) methods. All three modes of heat transfer (conduction, convection and radiation) have been analysed along with the design features of the brake assembly and their interfaces. The spin rig proved to be very valuable equipment; experiments enabled the determination of the thermal contact resistance between the disc and wheel carrier. The analyses demonstrated the sensitivity of this mode of heat transfer to clamping pressure. For convective cooling, heat transfer coefficients were measured and very similar results were obtained from spin rig experiments and CFD analyses. The nature of radiative heat dissipation implies substantial effects at high temperatures. The results indicate substantial change of emissivity throughout the brake application. The influence of brake cooling parameters on the disc temperature has been investigated by FE modelling of along drag brake application. The thermal power dissipated during the drag brake application has been analysed to reveal the contribution of each mode of heat transfer.