Different shapes of Fe3O4 nanoparticles on the free convection and entropy generation in a wavy-wall square cavity filled by power-law non-Newtonian nanofluid

Abstract

The goal of this paper is to investigate the influences of Nanoparticles volume fraction, Nanoparticles shape, amplitude and wavelength of wavy surface, Hartmann number and the Angle of magnetic field on the Nusselt number, Bejan number and the entropy generation rate in a wavy wall cavity, numerically. The nanoparticles are considered Fe3O4 which are magnetic in presence of magnetic and the base fluid is considered as a power-law non-Newtonian nanofluid which its density variation is approximated by the standard Boussinesq model. The wavy wall is maintained in low temperatures while the right wall has high temperature and up/down walls is insulated. The problem is solved by finite element method using FlexPDE commercial code and found that the highest average Nusselt number is observed for the Nanofluid with brick shaped particles; however, the Nanofluid with spherical shaped particles is found to have the lowest Nusselt. Furthermore, Minimum and maximum Bejan numbers were observed for brick and spherical nanoparticles, respectively.

Influence of the chamber inclination angle and heat-generating element location on thermal convection of power-law medium in a chamber

“…It was found that particles with a smaller radius significantly affect the fluid temperature growth. Free convection in a closed chamber having a wavy wall was investigated by Hatami (2018). The cavity was filled with a power-law medium, with the addition of Fe 3 O 4 nanoparticles.…”