Coupled CFD simulation of Brake duty cycle for Brake system design

Brake system design is intended to reduce vehicle speed in a very short time by ensuring vehicle safety. In the event of successive braking, brake system absorbs most of vehicles kinetic energy in the form of heat energy at the same time it dissipates heat energy to the surrounding. In this period temperatures on the brake disc shoots to higher side and during successive braking rotor may attain peak temperatures (above allowable limits). High temperatures on rotor disc affects durability & thermal reliability of the brake rotor. Excessive temperature on brake rotors can induce brake fade, disc coning which results in reduced braking efficiency. To address the complex heat transfer and highly transient phenomenon while successive braking, numerical simulations can help to analyse complex 3D flow physics and heat dissipation from rotors in the vicinity of brake system. Front loading of the simulation in initial design stages to optimize rotor design can improve brake design which in result can improve performance, reduce cost, and weight. In present work, two-way fully integrated coupling approach between two different environments (Power Flow) and (Power Therm) solver is used. The coupling will perform high quality data mapping and exchange between two solvers automatically. Coupling approach will help to capture transient nature of brake rotor heating. Estimated heat load with variable HTC's for different speeds is used as an input for standalone thermal model to predict maximum temperature rise in brake rotors due to conduction and radiation. Solid mesh is used for rotor disc and different parts of brake system to model conduction accurately. For results validation AMS (Auto-Motor-Sport) test procedure for 10 fade cycle is simulated. The results of the simulation are compared with the experimental data and found in good reasonable agreement.