To improve the cooling performance of a disc brake system, we introduce a new concept of bidirectional ventilated brake disc with an X-type lattice core. Transient and steady-state thermo-fluidic behaviors of the new brake disc are experimentally characterized and compared with a prevalent radial vane brake disc under identical conditions. Transient heating-up tests at a constant rotating speed, simulating continuous downhill braking, show that both brake discs exhibit a similar temperature during initial period, whilst evidently lower temperature can be achieved by the new brake disc under steady-state conditions. For a given rotating speed in typical operating range (i.e., 200-1000 rpm), steady-state tests reveal that the new brake disc provides 1-14% higher overall Nusselt number than the reference one. Although the X-type lattice core provides 43% less pumping capacity than radial vanes, more complex flow mixing and 1.1 times more heat transfer area caused by the lattice core are responsible for the superior overall cooling performance of the new brake disc. In addition, the morphological anisotropy of the lattice core induces circumferentially non-uniform heat transfer in the disc. The most open orientation of the lattice core provides substantially higher heat transfer than the most blocked orientation. Mechanisms of the anisotropic heat transfer pattern are experimentally explored. (C) 2014 Elsevier Ltd. All rights reserved.