Design and thermal performance of thermal diode based on the asymmetric flow resistance in vapor channel

To reduce the cost of the thermal diodes and increase its unidirectional heat transfer reliability, a thermal diode with tesla valve structure is proposed and its thermal performance is experimentally investigated. The relation between the structure parameters (including branch angle alpha, channel depth d, number of unit n and number of channel N) and the fluid flow performance of tesla vapor channel is studied by numerical simulation. According to the simulation results, the parameters of alpha = 30 degrees, d = 1.5 mm, n = 16 and N = 4 were chosen for the vapor channel in thermal diode. Experimental results show that the reverse thermal resistance is larger than the forward thermal resistance under the wide range of working conditions, indicating the good unidirectional heat transport capacity of the proposed thermal diode. The maximum ratio of reverse thermal resistance to forward thermal resistance K reaches around 3.02 under the filling ratio of 24% and the heating power of 7 W.