Thermofluidic Characteristics of a Porous Ventilated Brake Disk

Abstract

We introduce a new class of ventilated brake disk which incorporates an open cellular core: wirewoven bulk diamond (WBD). Transient and steadystate thermofluidic characteristics are presented. As reference, a commercially available pinfinned brake disk is also considered. At a braking power of 1.9 kW, representative of a medium sized truck descending a 2% gradient at a vehicle speed of 40 km/h (i.e., 200 rpm), the WBD cored brake disk reduces the overall brake disk temperature by up to 24% compared to the pinfinned brake disk. Results also reveal that in typical operating ranges (up to 1000 rpm), the WBD core provides up to 36% higher steadystate overall cooling capacity over that obtainable by the pinfinned core. In addition, the threedimensional morphology of the WBD core gives rise to a tangentially and radially more uniform temperature distribution. Although the WBD core causes a higher pressure drop, this is balanced by the benefit of a stronger suction of cooling flow. Flow mixing in an enlarged heat transfer area by the WBD core is responsible for the substantial heat transfer enhancement. The WBD core is mechanically strong yet light while providing a substantial reduction in a brake's operating temperature.