Magnetic nanofluid behavior including an immersed rotating conductive cylinder: finite element analysis

Hameed K Hamzah,M Hatami,Mohammed Y Jabbar,D Jing,Farooq H Ali

doi:10.1038/s41598-021-83944-0

Abstract

In this paper, numerical Galerkin Finite Element Method (GFEM) is applied for conjugate heat-transfer of a rotating cylinder immersed in Fe3O4-water nanofluid under the heat-flux and magnetic field. The outer boundaries of the cavity were maintained at low temperatures while beside the cylinder were insulated. It is assumed that the cylinder rotates in both clockwise and counter-clockwise directions. The dimensionless governing equations such as velocity, pressure, and temperature formulation were analyzed by the GFEM. The results were evaluated using the governing parameters such as nanoparticles (NPs) volume fraction, Hartmann and Rayleigh numbers, magnetic field angle and NPs shapes. As a main result, the average Nusselt number increases by increasing the NPs volume fraction, inclination angle and thermal conductivity ratios, while increasing the Hartmann number decreased the Nusselt number. Furthermore, platelet NPs had the maximum average Nusselt number and spherical NPs made the minimum values of Nusselt numbers among examined NPs shapes.

Highlights

In this paper, numerical Galerkin Finite Element Method (GFEM) is applied for conjugate heat-transfer of a rotating cylinder immersed in Fe3O4-water nanofluid under the heat-flux and magnetic field
To find the accuracy of the numerical method of the current computational software, fluid flow structure is presented by streamlines contour and heat-transfer is analyzed by isotherms contour and average Nusselt number
The validity of applied Galerkin finite element method (FEM) is examined by comparing the results with the literature v alues[2,30], as portrayed in Figs. 3, 4, and Tables 4, 5, respectively

Summary

Introduction

Numerical Galerkin Finite Element Method (GFEM) is applied for conjugate heat-transfer of a rotating cylinder immersed in Fe3O4-water nanofluid under the heat-flux and magnetic field. Khanafer et al.[9] studied this effect of two cylinders on mixed convection heat-transfer in a partially heated cavity, illustrating that the magnitude and direction of the rotation speed of the cylinders have a significant effect on the flow pattern, isotherms and Nusselt numbers. Farooq et al.[27] studied Cu-water nanofluid flow in an annulus enclosure with inner rotating corrugation cylinder of an average Nusselt number can be improved by increasing the Rayleigh number.

Results

Conclusion