Transient thermal regulation mechanisms of composite structures with interface thermal resistance

Abstract

Thermal rectification is a phenomenon similar to electrical rectification, in which heat transfer in one direction is favored and reverse heat transfer is hindered. In this study, the finite element method with interface thermal resistance for transient problems is proposed, and then transient thermal rectification of composite structures during the heating and cooling processes is investigated. Numerical results show that, in the initial 50 s of heating phase, increasing interface thermal resistance from 0 to 0.005 m2·K/W raised the average transient thermal rectification ratio from 1.32 to 1.46 for periodic boundaries, and from 1.22 to 1.31 for constant boundaries. During cooling, the ratio initially decreases due to resistance but then stabilizes, and the average thermal rectification ratio can be increased from 1.1 to 1.3 by increasing the interface thermal resistance. By changing the frequency, the oscillation frequency and amplitude of the thermal rectification ratio can be adjusted. In addition, a bimetallic structure with bi-directional heat transfer is designed, which includes the interface thermal resistance. The transient thermal rectification ratio is significantly increased by an order of magnitude through various interface heat transfer modes, and can be further improved through parameter optimization.

Keywords

• Transient thermal rectification
• Interface thermal resistance
• Bimetallic composite structures
• Finite element method