Thermal enhancement of microchannel heat sink using rib surface refinements

Heat transfer enhancement using the passive method of surface enhancers in microchannel heat sinks (MCHS) is always accompanied by increase in pressure drop and pumping power requirement. To reduce the pressure drop, a novel method of surface refinement is being proposed by transforming the ribs like surface enhancers to streamlined structures of the same cross-section. The performance of MCHS with and without surface refinement has been compared by evaluating pressure drop, Nusselt number and thermal enhancement factor for Reynolds number in the range of 100?1,000. The coning action of ribs results in a tremendous reduction in pressure drop with a negligible reduction in heat transfer thus, leading to a higher thermal enhancement factor for cones than ribs. Moreover, the performance improvement of various refined surfaces has been evaluated by computing percentage changes in pressure drop, Nusselt number, and thermal enhancement factor. Among all the cases, the surface refinement of the ribs has resulted in a maximum pressure drop reduction of 85% whereas the maximum reduction in Nusselt number is 25%; thereby achieving a thermal enhancement factor of 80%. The proposed surface refinement is expected to enhance the thermo-hydraulic characteristics as well as the energy consumptions of future generations of microelectronics.