Modeling and investigation of fluid flow affecting thermal boundary conductance at the solid-fluid interface

Abstract

Thermal conduction between solid and fluid is crucial in cooling technology based on micro and nanofluidics, while the impact mechanism of flow on interfacial thermal transport is yet to be studied due to the absence of simulation models. In this work, we propose a model to investigate the effect of fluid flow on the thermal boundary conductance between solid and fluid using molecular dynamics simulations. The present results indicate that the best way to eliminate viscous temperature rise is to control temperature by excluding velocity components along the flow direction rather than removing average velocity. The thermal conduction is insensitive to the fluid flow in atomic-smooth channel, but highly depends on the flow velocity in rough channel, where the thermal boundary conductance decreases by 11.7% when flow velocity reaches 18 m/s. The results are attributed to the variations of flow field, where the rough morphologies will disturb the parallel flow of fluid and restrain the thermal vibration of interfacial fluid. This work reveals the influence of fluid flow on interfacial thermal exchange, and the proposed model and results are helpful to improve the cooling systems based on microfluidics.