Investigation on the Influence of Nanofluids in Wavy Microchannel Heat Sink

This paper for the first time numerically investigates improvement of the heat transfer using wavy walls in microchannel heat sink (MCHS) with nanofluids as coolant. The effects of wavy amplitude, wavelength, volumetric flow rate, and volume fraction of different types of nanofluids are studied. Commonly used nanofluids like diamond–water, SiO2–water, and CuO–water nanofluids with temperature-dependent properties and nanoparticle volume fractions ranging from 1% to 5% are adopted. The results verify that the wavy MCHS yields better cooling performance than the traditional rectangular MCHS with pure water and nanofluids as coolants. Higher amplitude and shorter wavelength provides lower thermal resistance. However, the influence of nanofluids in wavy channel deteriorates with the increment in the amplitude and the decrement in the wavelength. Also with nanofluids at a high volume concentration of 5%, there is no significant difference in the performance observed between the wavy MCHS and the rectangular MCHS. The combination of wavy channel with a high volume concentration of nanofluids does not show the superior performance over the traditional channel with the same nanofluids and volume concentration.