Hydrothermal performance of microchannel heat sink: The effect of channel design

Abstract

This review article reports the influence of channel zone related geometrical parameters such as corrugated channel and flow disruption (FD) on the hydrothermal performance (HP) of microchannel heat sink (MCHS). Rapid increase in the power density accompanied by extreme miniaturization of electronic packages that demanded efficient cooling in MCHS is still to be explored. Despite several dedicated efforts for enhancing the heat transfer (HT) in MCHS an optimized technique is far from developed. The passive HT augmentation techniques for conventional channel also suffered from many limitations. In this context, corrugated channel appears as one of the prospective strategies due to the generation of Dean vortices (DVs) and chaotic advection (CA) in the bends. For efficient cooling, various channel shapes such as sinusoidal wavy, zigzag and convergent-divergent are introduced. The wavy MCHS with sinusoidal shape achieved high rate of HT with acceptable levels of PD compared with other shapes of zigzag and convergent-divergent MCHS. The other augmentation technique so called FD is established to be effective due to several interesting mechanisms including promotion of flow mixing, interruption of boundary layer, jetting, throttling and CA. Diverse FD methods such as grooves, cavities, ribs, hybridized ribs and grooves or cavities, offset-fin and interrupted wall channel are proposed. The hybrid techniques between ribs and either grooves or cavities have additional advantages than single technique in isolation. These features are manifested in increasing the HT area, induction of better fluid mixing and formation CA. The most important characteristic within flow disturbance techniques is found in interrupted-wall channel which manifested low PD. It is established to be the most desirable feature in MCHS applications due to its role in reducing the pump power and liquid leakage risk. We analyzed, discussed and made a comparative evaluation among various characteristics of geometrical parameters in each such technique to determine their impact on the HP of MCHS in terms of pressure drop (PD) and HT.