Numerical analysis on the liquid cooling of microchannel heatsink with phase change material

In this study, a microchannel heatsink with working fluid containing phase change material has been investigated numerically. The addition of phase change material in working fluid is to increase the heat transfer rate during cooling process. Commercial software ANSYS Fluent 15.0 is utilized to study the thermal resistance of the microchannel heatsink. Properties of working fluid with phase change material are with mass-averaged values. The numerical model for the phase change material used the latent heat as a function of heat capacity during phase change. This concept is modeled with user defined function in the simulation. The effects of microchannel geometry and the driven pressure difference between the entrance and exit of the heatsink on heat transfer performance are studied as well. The microchannel width varies in hundred micrometers with 2mm in height; the cross-sectional porosity of the fin array ranges from 0.6 to 0.7. Concentration of the phase change material in the working fluid is also a parameter in the investigation, ranging from 0% to 10%. The driven pressure difference of the working fluid is less than 30cm water head. The fin array covers an area of 1cm², and the power supply is 60W, such that the heat flux is 0.6MW/m².