Hybrid nanoparticle-enhanced fluid flow and heat transfer behaviors in a parabolic cavity with a heat source

Abstract

Natural convection of nanofluids holds considerable importance in both scientific research and engineering applications due to their exceptional heat transfer capabilities, which occur spontaneously without the need for additional energy input. In this paper, the natural convection of nanofluid inside a parabolic cavity containing a hot obstacle is studied numerically. The shape of the hot obstacle is selected as either circular or elliptical. Additionally, the effects of the Rayleigh number, nanoparticle volume fraction, and the position of the heat source are investigated. The computational fluid dynamics model was computed using COMSOL Multiphysics. It is observed that the average Nusselt number tends to increase with both the Rayleigh number and the volume fraction of nanoparticles in the fluid. When the heat source moves from the bottom region to the top area, the heat transfer performance of the heat source increases. When Ra ≤ 105, the cases with circular heat sources exhibit better heat transfer performance than those with elliptical heat sources. However, at Ra = 106, the average Nusselt number of the elliptical heat source is higher than that of the circular one.