Analysis of Drum Brake System with Computational Methods 2013-36-0022

Commercial vehicles have been more and more equipped with more powerful engines allowing considerable increase in size and load capacity. With this increase in capacity, it becomes important to evaluate the efficiency of the brake system to ensure vehicle safety during transportation of people and materials.

Braking efficiency of a vehicle is significantly affected by the heat generated by friction between stationary components and rotors. This heat raises the temperature of the components in brake assembly reducing the friction coefficient at the interface between brake lining and drum. Once the friction coefficient is reduced, the braking torque decreases. As consequence, it may cause undesirable scenarios such as braking performance loss due to overheating, tire burst, hub grease melting, brake lining failure, thermal cracking, geometric distortions and brake locking. All these scenarios directly impact the vehicle safety, generating demand for accurate predictions of components temperatures and thermal efficiency in the early stage of development.

The purpose of this work is to use computational methods to simulate the cooling effect on the drums in order to provide necessary improvements in the final design of the brake. The present study describes the thermal behavior of a drum brake assembly of a MAN commercial truck by using of Computational Fluid Dynamics technique (CFD). The validation of this method will bring several benefits to the brake development, like reduction of the design time and reduction of the prototype and application tests costs.

This paper describes CFD analysis of the unsteady heat dissipated through the truck rear wheels components (including hubs, brake drums, brake linings, rims and tires) after one typical cycle of brake application.

After computational simulation, CFD results were validated using a dataset obtained from experimental tests.