Department of Mathematics, Institute of Science, Banaras Hindu University, Varanasi-221005, India
The present paper deals with the linear thermal instability analysis of viscoelastic nanoﬂuid saturated porous layer. We consider a set of new boundary conditions for the nanoparticle fraction, which is physically more realistic. The new boundary condition is based on the assumption that the nanoparticle fraction adjusts itself so that the nanoparticle ﬂux is zero on the boundaries. We use Oldroyd-B type viscoelastic ﬂuid that incorporates the effects of Brownian motion and thermophoresis. Expressions for stationary and oscillatory modes of convection have been obtained in terms of the Rayleigh number, which are found to be functions of various parameters. The numerical results have been presented through graphs.