ENHANCEMENT IN THERMO-HYDRAULIC PERFORMANCE OF MICROCHANNEL HEAT SINK WITH SECONDARY FLOWS OF LEAF VENATION PATTERN

A new microchannel heat sink (MCHS) design comprising of secondary channels which connect neighboring primary channels are numerically analyzed to study their thermo-hydraulic characteristics. The inclusion of secondary channels in the continuous walls results in disturbance of thermal and hydrodynamic boundary layers which leads to drop in boundary layer thickness. Number of such secondary channel on either side of main channel will cause the flow to be continuously in developing state. The new MCHS are tested for heat flux range of 65 Watt per sq.cm to 200 Watt per sq.cm and cooled by water flowing at Reynolds number ranging from 650 to 1300. Compared to conventional MCHS, the thermal performance of new MCHS is higher but at the cost of pressure drop. The overall enhancement factor of the new design which is a function of Nusselt number and pressure drop of enhanced MCHS and conventional MCHS is 1.4 to 1.85.