Hydrothermal performance of microchannel heat sinks with wavy walls and cavity designs using nanofluids

This study investigates thermal performance enhancements in microchannel heat sinks using a passive hybrid design that combines corrugated walls and cavities. Three cavity shapes are compared against smooth microchannels, with CuO-water nanofluid serving as the coolant. Numerical simulations are conducted to evaluate the effects of cavity shape and corrugations on flow and temperature fields, with the aim of identifying the optimal design. The results indicate that incorporating cavities into corrugated microchannels improves hydrothermal performance by inducing flow disturbances and chaotic advection. At higher Reynolds numbers, triangular cavity microchannels achieve a Nusselt number that is 79% higher than that of rectangular cavities and 36% higher than that of circular cavities. The wall temperature reduction for WMCH-TC reaches 16 °C and 8 °C compared to other shapes at low Reynolds numbers. Increasing the nanofluid volume fraction further enhances heat transfer, yielding improvements of up to 85% compared to the base fluid.