Cooling Mechanisms in a Rotating Brake Disc With a Wire-Woven-Bulk Diamond Cellular Core

Abstract

Thermofluidic behaviors governing the enhanced cooling performance of the wire-woven-bulk diamond (WBD) cored brake disc in comparison with the conventional pin-finned brake disc used on heavy vehicles were characterized experimentally. For each type of brake disc, detailed internal thermofluidic data of the two rotating brake discs were obtained using transient thermochromic liquid crystal (TLC) for end-wall heat transfer and particle image velocimetry (PIV) for the inflow field. The results demonstrate that the pin-finned brake disc exhibits a circumferentially periodic curved inline-like passage flow and large dead flow regions, with strong recirculation that reduces its thermal dissipation performance. The cooling advantage of the WBD core is primarily attributed to the combination of enlarged heat transfer surface area (both end-wall and core) and greater utilization of the larger surface due to favorable fluidic behavior developed from the WBD topology. The internal WBD core has approximately three times the surface density of the pin-finned disc which, in combination with the smaller and weaker recirculation zones, leads to more effective usage of the available core surface area for thermal dissipation. The aerodynamic anisotropy of the WBD core induced by its topological anisotropy causes a globally irregular thermofluidic distribution in the brake disc.