Enhanced heat transfer characteristics of nano heat exchanger with periodic fins: A molecular dynamics study

Abstract

Enhancing convective heat transfer between cold and hot fluids at nanoscale is crucial to improve the heat dissipation capability of micro/nano electronic devices. Here, a modified thermal pump method is applied to simulate the heat transfer characteristics in nano heat exchangers with periodic rectangular and triangular fins, by using molecular dynamics simulation. Temperature jump and velocity slip are observed at the wall-fluid interface for both cold and hot sides at nanoscale. Fins are found to boost the temperature development of fluids and enhance heat transfer characteristics of nano heat exchangers. Convective heat transfer increases with reduction of the nondimensional period length of the fins due to expansion of heat transfer areas. The heat transfer performance of nano heat exchangers with periodic rectangular fins is superior to that with triangular fins. The results demonstrate that more near-wall fluid atoms act as “phonon bridge” to enhance heat transfer performance in nano heat exchangers with fins. Meanwhile, the expansion of heat transfer areas caused by fins facilitates more near-wall fluid atoms to gather at low potential regions to participate in heat transfer of nano heat exchangers.