Heat Transfer Characteristics of Ventilated Disc Brake Rotor with Diamond Pillars-A Review

Abstract

Ventilated brake discs are used in modern vehicles such as passenger and racing cars as they require high speed braking system. The heat generated during braking operation is stored in brake disc and this heat is rejected to surrounding mainly by forced convection. Effective design of brake rotor is an essential to achieve proper cooling of braking system. The brake discs are available in various configurations such as radial type and pillared type brake rotors. It is found that thermal failure of brake disc is not only due to high temperature, but also due to high thermal stresses developed due to large temperature gradients within rotor passages. The temperature distribution within vane passage of radial vane rotors is not uniform and it leads to high thermal stresses. Pillared rotors are alternative to radial vane rotors as they have more uniform temperature distribution within rotor passages. Even though mass flow rate in case of pillared rotors is less than radial type rotors, the rate of heat transfer is almost same in both cases. This paper mainly focuses on understanding of air flow and heat transfer characteristics of diamond pillared rotor. Further, results of diamond pillared rotor are compared with other configurations of ventilated disc brake rotors. Mass flow rate through passages of diamond pillar (DP) rotor is 26% lower than tapered radial vane (TRV) rotor. Although diamond pillar (DP) has a noticeably lower mass flow rate than TRV rotor, the passage heat dissipation is approximately same for both configurations.