Two-phase simulation of irreversibilities for Ag–water nanofluid flow inside an elliptical pin-fin heat sink: Entropy generation and exergy considerations

Abstract

It is beyond doubt that the first-law perspective is incapable to evaluate the energy losses, and realizing real optimum conditions of thermal equipment only boils down to the second law of thermodynamics. This paper examines the second law phenomena of a nanofluid within an elliptical pin-fin heat sink. The current outcomes provide the design insight for developing optimum pin-fin heat sinks for use in high-performance electronic devices. The numerical modeling based on the finite volume method is adopted. Elliptical pin fins with a larger fin density cause lower thermal irreversibility. The higher fin density intensifies the frictional irreversibility at higher Reynolds numbers. Adding the nanoparticles improves the temperature uniformity and causes less thermal entropy generation, while it augments the frictional irreversibility. Depending on the Reynolds number, there are optimum values of the fin density at which the minimum irreversibility happens. The Bejan number gradually declines as the fin density rises.