Improving thermal performance of microchannels by combining rectangular pin with chamber

The microchannel heat sink is an effective liquid cooling technique in thermal management of miniature systems. In the current work, to enhance the performance of a microchannel, the combination of rectangular pin with chamber is proposed and studied. A numerical study is carried out, and the governing equations are discretized by the finite volume method using the semi-implicit method for pressure linked equations algorithm. The reliability of the numerical results is verified based on the experimental section of this study. The deviations of the comparison fall in satisfactory ranges (maximum error of 8%). All the complex geometries have the same overall dimensions (height, width, and length) as the smooth microchannel, and a constant heat flux of 100 kW/m(2) is applied. Water is used as working fluid, and all cases are examined in the Reynolds number ranging from 423 to 1990. The results illustrate that both the pin and the chamber boost the heat transfer coefficient of the microchannel with a penalty in the pressure drop. It is also found that in the case equipped with the rectangular pin and chamber, there is a 2.3%-53.1% increase in the heat transfer coefficient, and a 3.6%-681.4% increase in the pressure drop, compared with the reference model. Furthermore, the position of the pin and chamber affects the overall performance of the microchannel. It can be concluded that the enlargement in the length of the chamber improves the overall performance of the combined model, while the enlargement in the length of the pin has an inverse impact.