Vol.17, No.2, 2017, pp.113–120
UDC 532.516

Thermal instability of Maxwell visco-elastic nanofluid in a porous medium with thermal conductivity and viscosity variation for more realistic boundary conditions is investigated theoretically. A Darcy model is considered for the porous medium. The model used for nanofluid incorporates the effect of Brownian diffusion and thermophoresis. The eigen value problem is solved by employing the Galerkin weighted residuals method. The influence of the Lewis number, nanoparticle Rayleigh number, modified diffusivity ratio, the viscosity variation parameter, the thermal conductivity variation parameter and porosity parameter on the stationary convection is studied and it is found that the Lewis number, modified diffusivity ratio and nanoparticles Rayleigh number destabilizes while the viscosity variation parameter, the thermal conductivity variation parameter and porosity parameter stabilize the stationary convection.

Keywords: nanofluids, Darcy model, Lewis number, viscosity variation, Galerkin weighted residuals method, porous medium