Convective instability in binary nanofluids with an internal heat source in the presence of thermodiffusion and nanoparticles

Abstract

AbstractThis paper investigates the effect of internal heat source on the convective instability under the effect of thermodiffusion of nanoparticles and solute in binary nanofluids theoretically using stability criterion based on linear stability theory. A horizontal layer of binary nanofluid at constant and different temperatures is considered, and the problem is modeled by the system of highly nonlinear partial differential equations. These coupled equations are transformed into ordinary differential equations using nondimensional variables. To study the convective instability of a binary nanofluid, the Rayleigh numbers are derived analytically for stationary and oscillatory convections and the addition factor Fa is proposed. The comparison of the obtained results is favorable with previously published results. The Brinkman model for viscosity and the Bruggeman model for thermal conductivity are used to study the effect of nanoparticle on the system. The effects of various parameters, namely internal Rayleigh number, volume fraction of nanoparticles, Soret coefficients of nanoparticles, and solute on the system are shown through graphs. To check the variation in stability, we have considered NH3/H2O+Ag binary nanofluid and the effect of addition factor on the concentration profiles are explained with the help of a graph.