Numerical investigation of heat transfer performance in parallel and symmetric wavy microchannel heat sinks

Micro-channel heat sinks have advantages such as a high surface area-to-volume ratio, a large heat transfer coefficient, and lightweight design, making them crucial for microelectronics and aerospace applications. Numerical simulation was conducted to analyze the fluid-flow and heat transfer characteristics in the newly designed heat sink at Reynolds number ranging from 147-736. The symmetric wavy micro-channel heat sinks were compared with the parallel wavy micro-channel heat sinks based on friction coefficient, Nusselt number, and comprehensive performance factor. The results indicate that periodic variation in the cross-sectional area of the symmetric wavy micro-channels generates vortices at the valleys, enhancing fluid mixing. In contrast, the fluid in the parallel wavy micro-channels exhibits a wave-type flow pattern, where the wavy structure disrupts the flow boundary-layer. The fluid-flows along the streamlined boundary with less flow friction. This enables heat transfer enhancement under lower pressure drop conditions. The geometrical parameters for optimal heat transfer performance are obtained by adjusting the amplitude ratio, ?. The comprehensive performance factor for the parallel wavy micro-channels, with a Reynolds number of 736 and a value of ? = 4, is 1.64.