Adsorption-controlled thermal diode: nonequilibrium molecular dynamics simulation

Abstract

A thermal diode is a system controlling the heat transfer preferentially in. one direction. This serves as a basic building block to design advanced thermal management systems in energy saving applications and to provide implications to design new application such as thermal computers. The development of the thermal diode has been of great interest as electrical diodes have similarly made significant impacts on modern industries. Numerous studies have demonstrated thermal diode mechanisms using non-linear heat transfer mechanisms, but the main challenges in current systems are poor" steady-state performance, slow transient response, and/or extremely difficult manufacturing for the viable solutions. In this study, an adsorption-based thermal diode is examined for a fast and efficient thermal diode mechanism as a completely new class, using a gas-filled, heterogeneous nanogap with asymmetric surface interactions in Knudsen regime. Ar gas atoms confined in Pt-based solid surfaces are selected to predict the degree of rectification, R similar to 10, using non-equilibrium molecular dynamics simulation with the nanogap size of L-z = 20 nm and Delta T = 20 K for various average plate temperatures, 80 < T < 130 K. Different surface energies for the thermal diode is studied and a maximum degree of rectification, R-max similar to 10, is found at T = 80 K which results from the significant adsorption-controlled thermal accommodation coefficient (TAC). The obtained results provide insights into the design of advanced thermal management systems including thermal switches and thermal computing systems.