Investigation on the heat transfer and energy-saving performance of microchannel with cavities and extended surface

Abstract

Microchannel heat sinks (MCHSs) are widely used in microelectronic systems and are one of the most effective heat sinks in the 21st century. In this work, the fluid flow and heat transfer performance of different extended surfaces (cylindrical fins, rectangular fins, water droplets) of triangular combined cavity, 90° fan-shaped and triangular combined cavity were investigated. The comprehensive performance in microchannels were analyzed and evaluated in detail by different aspects, including flow characteristics, heat transfer characteristics, pressure drop characteristics, comprehensive thermal strengthening performance and thermal strengthening performance aimed at energy saving. The result indicated that the microchannel with the triangular combined cavity exhibited the best heat transfer performance at a low Reynolds number. However, as the Reynolds number gradually increasing, the microchannel with 90° fan-shaped and triangular combined cavity presented more obvious advantages. Furthermore, the microchannel is evaluated by the comprehensive thermal enhancement performance and the enhanced performance evaluation aiming at energy-saving. When Re<144.6, the comprehensive heat transfer performance of the microchannel with triangular combined cavity cylinder fins was the best, and the energy-saving effect was excellent. The microchannel of the 90° fan-shaped and triangular combined cavity cylindrical fins at Re>144.6 had better comprehensive heat transfer performance and energy-saving effects. Because of the combined effect of the boundary layer redevelopment and the cold and heat exchange of the fluid in the channel, the microchannel with cavity and the extended surface has better heat transfer and energy-saving performance than that of the traditional rectangular microchannel.