Thermal rectification enhancement of bi-segment thermal rectifier based on stress induced interface thermal contact resistance

摘要

Thermal rectification is the phenomenon that heat flows much easier from forward direction than reverse direction across the structure. Materials with temperature-dependent thermal conductivity and/or variable cross section area segments are always adopted to utilize obvious thermal rectification effect. Previous studies often ignored the effect of thermal contact resistance between the two segments of traditional bi-segment thermal rectifier. Since interface thermal contact resistance also contributes significantly to the total effective thermal conductivity of the rectifier, the present paper proposed a finite element scheme to simulate the thermomechanical coupling problem caused by the stress-dependent thermal contact resistance. The proposed method is verified and validated with analytical and experimental examples respectively, and numerical results show the effect of thermal contact resistance on the optimization of thermal rectification ratio. Several key parameters such as the initial gap between the two segments and the thermal contact resistance model parameters are investigated numerically, and the present paper provide a novel approach and design guidance to manipulate heat flux through stress-dependent thermal contact resistance.