Stability Analysis of Double-diffusive Convection in a Couple Stress Nanofluid

Abstract

Stability of double-diffusive convection in a horizontal layer of nanofluid is studied. The couple-stress fluid model is employed to describe the rheological behavior of the nanofluid. Stability of nanofluid has been influenced by the features of couple-stress fluid, suspended nanoparticles and examined under the consideration of momentum and thermal slip boundary conditions. By applying normal mode analysis method and linear stability theory, the dispersion relation describing the effect of various parameters is derived. We have assumed that the nanoparticle concentration flux is zero on the boundaries which neutralizes the possibility of oscillatory convection and only stationary convection occurs. The impact of the physical parameters, like the couple stress parameter, solutal-Rayleigh Number, thermo-nanofluid Lewis number, thermo-solutal Lewis number, Soret parameter and Dufour parameter have also been observed and compared with the published work. A very good agreement is found between the present paper and earlier published results.