Effect of Surface Microstructure on Microchannel Heat Transfer Performance

Abstract

In this paper, forced convection heat transfer occurring in microchannels with different microstructures is investigated numerically. It is found that vortices will appear in the microstructure grooves. The influence of microchannel geometries on heat transfer performance is evaluated by Nusselt number and the entrance effect is noted for all geometries. Compared with the plain plate surface, a much more moderate decrease of local Nusselt number can be found for all the grooved microstructures, indicating more uniform heat transfer intensity along the flowing direction. The results also suggest that the heat transfer performance improves with inlet Reynolds number. The V-shaped grooved microstructure possesses the highest heat transfer performance. Compared with the plain plate surface, averaged Nusselt number can be increased by about 1.6 times. Through the field synergy principle analysis, we find that it is the synergy between temperature gradient and velocity that results in different heat transfer performance for different microstructures.