Numerically investigating the effects of cross links in scaled microchannel heat sinks

Abstract

Mass flow rate of liquid, kg/s j Superficial gas velocity, m/s Thermal management for high performance of miniaturized electronic devices using microchannel heat sinks has recently become of interest to researchers and industry. Obtaining heat sink designs with uniform flow distribution is strongly desired. A number of experimental studies have been conducted to seek appropriate designs for microchannel heat sinks. However, pursuing this goal experimentally can be an expensive endeavor. The present work investigates the effect of cross-links on adiabatic two-phase flow in an array of parallel channels. It is carried out using the three-dimensional mixture model from the computational fluid dynamics (CFD) software, Fluent 6.3. A straight channel and two cross-linked channel models were simulated. The cross-links were located at 1/3 and 2/3's of the channel length, their width varied by one and two times the channel width. All test models had 45 parallel rectangular channels, with a hydraulic diameter of 1.59 mm. The results showed that the trend of flow distribution agrees with experimental results. A new design, with cross-links incorporated, was proposed and the results showed a significant improvement, up to 55%, on flow distribution, compared to the standard straight channel configuration without a penalty in the pressure drop. The effect of cross-links on flow distribution, flow structure, and pressure drop was also documented.