Flow and Heat Transfer Analysis of a Ventilated Disc Brake Rotor Using CFD 2008-01-0822
In the present work, an attempt was made to study numerically, using CFD, the effect of vane-shape on the flow-field and heat transfer characteristics of a disc brake rotor for different configurations and at different speeds. Initially, the CFD code used in this work was validated by experimental results obtained by conducting experiments on a test rotor using particle image velocimetry (PIV). Further, six types of rotor configurations viz., straight radial vane (SRV), tapered radial vane (TRV), modified tapered radial vane (MTRV), circular pillared (CP), diamond pillared (DP) and modified diamond pillared (MDP) were considered for the numerical analysis. Three of them were radial type and other three were of pillared type rotors. A rotor segment of 20° was considered for the numerical analysis due to rotational symmetry.
Validation was done for SRV rotor, for which the experimental and predicted results were in good agreement. The maximum deviation of the numerical results was about 10% from the experimental results. It was found that among the six types of rotor configurations considered for the analysis, MTRV rotor allows more air flow through the rotor (4.43 g/s at 1800 rpm), which was 35% more than that of SRV rotor. In addition, it was found that the heat dissipation from the surfaces of MTRV rotor was the highest i.e., about 20% more than SRV rotor and 9% more than MDP rotor. Among all the rotor configurations considered, the heat transfer from the passage surfaces was symmetrical in pillared rotors. Hence, for modern high-speed vehicles, ventilated pillared rotors may be more appropriate.