## THERMAL SCIENCE

International Scientific Journal

### THERMAL INSTABILITY OF COMPRESSIBLE WALTERS’ (MODEL B′) FLUID IN THE PRESENCE OF HALL CURRENTS AND SUSPENDED PARTICLES

**ABSTRACT**

Effect of Hall currents and suspended particles is considered on the hydromagnetic stability of a compressible, electrically conducting Walters’ (Model B′) elastico-viscous fluid. After linearizing the relevant hydromagnetic equations, the perturbation equations are analyzed in terms of normal modes. A dispersion relation governing the effects of visco-elasticity, magnetic field, Hall currents and suspended particles is derived. It has been found that for stationary convection, the Walters’ (Model B′) fluid behaves like an ordinary Newtonian fluid due to the vanishing of the visco-elastic parameter. The compressibility and magnetic field have a stabilizing effect on the system, as such their effect is to postpone the onset of thermal instability whereas Hall currents and suspended particles are found to hasten the onset of thermal instability for permissible range of values of various parameters. Also, the dispersion relation is analyzed numerically and the results shown graphically. The critical Rayleigh numbers and the wavenumbers of the associated disturbances for the onset of instability as stationary convection are obtained and the behavior of various parameters on critical thermal Rayleigh numbers has been depicted graphically. The visco-elasticity, suspended particles and Hall currents (hence magnetic field) introduce oscillatory modes in the system which were non-existent in their absence.

**KEYWORDS**

PAPER SUBMITTED: 2009-08-01

PAPER REVISED: 2010-01-20

PAPER ACCEPTED: 2010-02-24

**THERMAL SCIENCE** YEAR

**2011**, VOLUME

**15**, ISSUE

**2**, PAGES [487 - 500]

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