Research Journal of Engineering and Technology

Jyoti Ahuja ¹, Urvashi Gupta ², R. K. Wanchoo ²

Affiliations
1 Energy Research Centre, Panjab University, Chandigarh-160014, IN
2 Dr. S.S. Bhatnagar University Institute of Chemical Engineering & Technology, Panjab University, Chandigarh-160014, IN

Abstract

In the present paper, hydromagnetic stability of alumina-water and copper oxide-water nanofluids is investigated for top heavy configuration of nanoparticles. Brownian motion and thermophoretic forces are introduced due to the presence of nanoparticles and Lorentz force term is added in the momentum equation due to the presence of magnetic field. The problem has application in geophysics due to earth’s magnetic field and enhanced heat transfer characteristics of nanofluids. Computations are carried out within the frame work of normal mode technique and single term Galerkin approximation. An eigen value equation representing the relation between various nanofluid parameters, magnetic field, growth rate of disturbance and wave number is obtained. It is observed that the thermal Rayleigh number increases with the increase in Chandrasekhar number and decreases with the increase in volume fraction of nanoparticles. Nanofluids with Al2O3 nanoparticles exhibit higher stability than the nanofluids containing CuO nanoparticles. The mode of instability is found to be through stationary convection. It is expected since for oscillatory motions to exist two of the buoyancy forces must act in the opposite directions.

Keywords

Nanofluids, Brownian Motion, Hydromagnetics, Critical Rayleigh Number.

Full Text