Title: Thermomagnetic convection in a layer of magnetic nanofluid saturating porous medium with magnetic field dependent viscosity

Authors: Amit Mahajan; Mahesh Kumar Sharma

Addresses: Department of Applied Sciences, National Institute of Technology Delhi, Delhi – 110040, India ' Department of Applied Sciences, National Institute of Technology Delhi, Delhi – 110040, India

Abstract: In this paper, the effect of magnetic field dependent (MFD) viscosity on the onset of thermomagnetic convection is examined for a horizontal layer of magnetic nanofluid (or ferrofluid) saturated porous layer. A model that comprises the effect of Brownian diffusion, thermophoresis, magnetophoresis, and Darcy's law is considered. We employed the Chebyshev pseudospectral QZ-method to solve the developed mathematical model and the results are derived for water-based and ester-based magnetic nanofluids. The effects of significant parameters are analysed at the onset of convection in the gravity as well as in the microgravity environment. The influence of MFD viscosity, permeability parameter, the width of the fluid layer, Lewis number, Langevin parameter, particle concentration, and the concentration Rayleigh number at the onset of thermomagnetic convection are graphically illustrated.

Keywords: magnetic nanofluids; thermomagnetic convection; magnetic field dependent viscosity; microgravity; Darcy medium.

DOI: 10.1504/IJNP.2019.102586

International Journal of Nanoparticles, 2019 Vol.11 No.3, pp.181 - 201

Received: 21 Apr 2018
Accepted: 13 Nov 2018
Published online: 30 Sep 2019 *

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