Thermal Performance Analysis of Slug Flow in Square Microchannels

Abstract

Thermal performance enhancement of microchannel heat sinks for electronics cooling is becoming more and more necessary. To this end, microchannels with noncircular cross-sections conveying immiscible droplets have been employed in this study and geometric manipulations are applied to enhance fluid mixing and consequently achieve a higher rate of heat removal. Three-dimensional numerical simulations are performed using volume of fluid method for channels of 100?µm hydraulic diameter. Constant wall temperature is chosen as the boundary condition for heating section of the channels. Effects of parameters such as adding curvature to the side walls and varying the entering velocity of the base liquid on heat transfer rate are studied. A performance coefficient is used to evaluate the relative impact of increase in both the Nusselt number and pressure drop as a result of adding curvature to the channel walls. Results of the study showed that slug flow in curved channels is capable of improving the thermal performance in comparison with single liquid flow in straight channels and in best case, can improve the performance up to 50%.