Numerical Analysis for Augmentation of Thermal Performance of Single-Phase Flow in Microchannel Heat Sink of Different Sizes with or without Micro-Inserts

Abstract

With the development of miniaturized and enormous heat density generating novel technologies, the microchannel heat sink is rapidly establishing itself in modern cooling fields. Enhancement of heat transfer performance of microchannels is done by incorporating improved design structure, changing working fluids and flow conditions, using different materials for fabrication, etc. Coupling of two parameters influencing heat transfer performance of microchannels is in a nascent age, and complex coupling of heat transfer influencing parameters of microchannel sinks has not been clearly understood yet. This study provides the thermal-fluid flow features–fluid flow characteristics and heat transfer characteristics- of single-phase flow in microchannel of different sizes with or without microinserts by the use of computational fluid dynamics. The numerical simulation is performed by employing distilled water with thermophysical properties that depends on temperature for the Reynolds number range of 56–2242. The effect of microinserts on characteristics of fluid flow and heat transfer is analyzed. The results of numerical analysis show that heat transfer performance in microchannel with microinserts is enhanced effectively, however resistance in fluid flow is increased simultaneously. The 0.5 mm microchannel with microinserts shows the best performance of heat transfer characteristics with enhancement of 1–9% in the Reynolds number range of 56–2242 with simultaneous maximum increase in pressure drop by 14.5%. It’s overall performance, evaluated by thermal performance factor, is found to be best among all cases of three different channel sizes with and without microinserts. The maximum enhancement of heat transfer is found to be in case of 0.5 mm channel size with microinserts by a factor of 1.09. The maximum pressure drop is increased is found to be by factor of 2.28 in case of 2 mm channel size with microinserts.