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Brake disc cooling is an important area of research for high-performance brake disc manufacturers, users as well as academia. In high-demand braking applications, vented discs are increasingly being used as these are considered to have high heat-dissipating characteristics. The cooling efficiency of ventilated brakes depends on three key characteristics: the mass flowrate through the disc, i.e. the pumping efficiency of the rotor, the average heat transfer coefficient on the surface of the disc, and the wetted area of the rotor. Recent research has shown that the pin-vented discs have high heat transfer rates because of an increase in turbulence which results in a higher heat transfer coefficient. The pin-vented discs also have a higher resistance to thermal deformation owing to the more even distribution of material, resulting in lower thermal stress build-up within the rotor. The pin-vented discs in general have multiple rows of pins. In this paper an optimal configuration of various rows has been found for the maximum heat transfer rate. It has also been found that the ratio of wetted area of the disc to the frontal area of pins defines the heat transfer rate from the disc uniquely and can be used as a design parameter for the optimal design of a brake disc.

Increasing demand from the consumer for higher levels of refinement from their passenger vehicles has put considerable pressure on the automotive industry to produce ever quieter cars. In order to prevent the occurrence of many forms of brake noise, especially judder and drone, excessive heating of the brake disc must be avoided, while minimizing temperature variations across the rotor. In order for this to be achieved the brake rotor must be designed such that it ensures sufficient uniform heat dissipation and thermal capacity. In high-demand braking applications, vented discs consisting of two rubbing surfaces separated by straight radial vanes are normally employed, as they utilize a greater surface area to dissipate heat. Within this paper the effects of changing the geometry of the first row of pins on aerothermodynamic properties of a pin-vented brake rotor are investigated using computational fluid dynamics (CFD). The validated CFD model shows that decreasing the thickness of the first row of pins by 10 per cent improves the mass flowrate through the rotor by 14 per cent and the heat transfer rate by 6 per cent. The results obtained can be used for the design of brake discs which are efficient with respect to heat dissipation.

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