Effect of Local Thermal Nonequilibrium on the Stability of the Flow in a Vertical Channel Filled With Nanofluid Saturated Porous Medium

Abstract

The stability of nanofluid flow in a vertical channel packed with a porous medium is examined for the local thermal non-equilibrium state of the fluid, particle and solid-matrix phases. The effects of Brownian motion along with thermophoresis are incorporated in the nanofluid model. The Darcy-Brinkman model for the flow in a porous medium and three-field model, each representing the fluid, particle and solid-matrix phases separately, for temperature is used. A normal mode analysis is used to obtain the eigenvalue problem for the perturbed state, which is then solved using the Chebyshev spectral collocation technique. The critical Rayleigh number and corresponding wavenumber are presented graphically for the effect of different local thermal non-equilibrium parameters. It is noticed that the influence of LTNE parameters on the convective instability is significant.