ONSET OF DOUBLE-DIFFUSIVE NANOFLUID CONVECTION IN A LAYER OF SATURATED POROUS MEDIUM WITH THERMAL CONDUCTIVITY AND VISCOSITY VARIATION

The effects of thermal conductivity and viscosity variation on the onset of double-diffusive convection in a nanofluid-saturated porous layer heated and salted from below is studied using linear stability analysis. A two-component non-homogeneous equilibrium model is used for the nanofluid that incorporates the effects of Brownian motion and thermophoresis. The resulting eigenvalue problem is solved using a Galerkin method that gives the criterion for both stationary and oscillatory convection. It has been observed that, the thermal conductivity and viscosity variation with nanoparticle volume fraction delay the onset of convection.