摘要

This study investigates numerically the effect of increasing heat load on thermal performance of six different heat sinks. The heat sinks examined were the single-layered microchannel, two-layered microchannel with parallel and counter-flow configurations, single-layered microchannel with micro pin-fin inserts and the two-layered microchannels with micro pin fins inserts and different flow configurations. The objective of this investigation was to identify the heat sink that performs best under high heat load conditions. The thermal performance was based on two criteria namely, minimised peak temperature and minimised temperature rise on the heated base of the solid substrate. The heat load on the heated base was increased from 100 to 1000 W and results obtained showed that inserting micro pin fins into the microchannels enhances the thermal performance of the heat sink under increased heat load. Also, for the highest heat load of 1000 W and lowest pressure drop of 10 kPa considered, the single-layered microchannel with six rows of micro pin-fin inserts performed best in minimising temperature rise on the heated base while the two-layered microchannel with four rows of micro pin-fin inserts performed best in minimising peak temperature.