Investigation of the effect of changing the type of fluid on the hydrodynamic and thermal characteristics of the flow in a thermal micro-heatsink

In recent years, many studies have been conducted on micro-heat sink. Micro-heat sink absorbs heat from the equipment and transfer heat to that fluid by maximizing the contact surface with the surrounding fluid. In the present work, the three-dimensional simulation of nanofluid flow in a heat sink with fins with triangular arrangement and circular cross-section with a height of 1.5 mm and uniform heat flux is discussed. The simulation was done with the help of Ansys Fluent 2019 commercial software. The boundary condition of constant and uniform heat flux is applied on the bottom wall of the heat sink. The effects of nanoparticle volume fraction, nanoparticle type and Reynolds number on the hydrodynamic and thermal performance of the thermal well are investigated. Two types of nanofluid and one type of hybrid nanofluid are investigated in three volume fractions of 0.01-0.02-0.04. In this research, first the pressure drop and heat transfer are investigated, then the best nanofluid is determined by defining the thermal performance coefficient. The results show that heat transfer decreases with increasing volume fraction in water-aluminum oxide nanofluid, but heat transfer increases with increasing volume fraction in water-copper nanofluid. Also, heat transfer increases in the water-aluminum-copper hybrid nanofluid at a volume fraction of 0.04 from the Reynolds number range of 400 and above.