Microchannel Heat Sink with Designed Roughness: Analysis and Optimization

Abstract

power are taken as objective functions. Navier–Stokes and energy equations for laminar flow and conjugate heat transfer are solved for flow analyses using a finite volume solver. Thermal resistance is decreased and the Nusselt number is increased at the expense of pressure drop in a ribbed microchannel. Thermal resistance in a ribbed channel is generally higher than that in a smooth channel for fixed pumping power, but the difference in thermal resistance reduces as pumping power increases. The design variable of the ratio of rib height to width of channel is primarily responsible for and the most sensitive to the heat transfer augmentation, whereas ratios of width to height of the rib and channel width to pitch of the rib are found to be less sensitive in the design space. The ratio of channel widthtopitchoftheribisfoundtobethemostPareto-sensitive(sensitivealongthePareto-optimalfront),whereasthe ratio of width to height of the rib is found to be the least Pareto-sensitive. Nomenclature Ac = cross-sectional area of the microchannel As = surface area of the substrate base Cp = specific heat dh = hydraulic diameter E = error vector