Design of Solid-Gas Interfaces for Enhanced Thermal Transfer.

摘要

Using the molecular dynamics simulation and related analysis we investigated the thermal accommodation coefficient (TAC) and the momentum accommodation coefficient (MAC) to quantify the solid-gas energy and momentum exchange efficiencies. We determined the effects of individual interfacial parameters including, (i) solid-gas interaction strength, (ii) gas-solid atomic mass ratio, (iii) solid elastic stiffness, and (iv) temperature, on TAC and MAC at solid surfaces in contact with monoatomic and diatomic gases. We demonstrated that the TAC and MAC can be significantly enhanced by proper surface modifications. Specifically, for metal surfaces modified with organic self-assembled monolayers (SAMs), both TAC and MAC are close to its theoretical maximum and are essentially independent from the details of the SAM-gas interactions characteristics. Our work provided clear guidelines for solid surface modification enabling efficient energy exchange at the solid-gas interface and generated an extensive database for the TAC andMAC which can be utilized in the design of gas cooling systems critical in thermal management of a wide range of a wide range of active electrical and mechanical components used in the Air Force hardware.