Abstract

High-power electronic devices are now widely applied in computer, mechanical and sustainable energy industries. As electronic devices become further more integrated and powerful, more effective cooling is required to remove increasing heat fluxes generated by smaller devices. Microchannel heat sink has been recognized as a very promising cooling technology since it was brought up by Tuckerman and Pease.
The purpose of the present work is to numerically study the cooling performance of microchannel heat sinks under non-uniform heating conditions and to compare to that under uniform heating conditions. Water with temperature-dependent properties is used. The temperature distribution, pressure drop, and total thermal resistance of the heat sink are selected as criteria of their cooling performance. The heat sinks are tested under various inlet velocities and heat fluxes. Firstly, cross-linked microchannel heat sink is used for cooling of heat source with hotspots. Three widths of cross-linked channel which are 0.5 mm, 1 mm, 2 mm are compared to straight channel with different positions and amount of hotspots on the bottom surface of the heat sink. Secondly, straight channel micro heat sinks are studied and optimized
IV
under continuously varying heat flux conditions. Two layouts of the heat sink are proposed on which heat fluxes change perpendicular and along flow direction, respectively. Then, the layout with better cooling performance is optimized with Taguchi method. Finally, a novel swirl channel heat sink is employed for cooling of continuously varying heat flux conditions on a circular plate and is compared to uniform heating. Erenow, four cross sectional geometries of the channel (rectangular, trapezoidal, inverse-trapezoidal, and isosceles triangular) are compared for the heat sink.