Performance evaluation of serpentine and multi-channel heat sinks based on energy and exergy analyses

Abstract

A numerical and experimental study is conducted to enhance and compare the thermo-hydraulic characteristics of two types of rectangular mini-channel heat sinks, namely, the serpentine mini-channel heat sink and multi-mini-channel heat sink. The comparisons of the improvement of heat transfer and fluid flow in the two heat sinks with five designs were conducted in terms of energy and exergy analysis. The finite volume technique was employed to solve the governing equations under laminar flow conditions with water as a cooling medium. The new designs included using two techniques; the first is using only ribs mounted on the sidewall with semi-circular and semi-elliptical shapes. While the second technique is based on integrating the pin fins, that mounted in the center of channels, with grooves on the channels sidewalls. The optimum design obtained from the numerical simulation was fabricated and experimentally tested to verify the reliability of the numerical simulation. The results showed that the incorporation of the pin-fins with grooves is effectively improved the heat dissipation for both designs compared with using only ribs. The Nusselt numbers attain about 33.85, 12.2 for the serpentine mini-channel heat sink, and multi-mini-channel respectively, while the pressure drop reached about 14190, 363.8 Pa. Meanwhile, the percentage of enhancement in exergy efficiency reached 24% and 37% for serpentine minichannel and multi-minichannel heat sinks, respectively.