Radiation Effects on Mixed Convection Flow and Viscous Heating in a Vertical Channel Partially Filled with a Porous Medium

A theoretical analysis is made for a fully developed mixed convection viscous fluid flow between two infinite vertical parallel plane walls, where a porous substrate of finite thickness is attached to the left vertical wall, in the presence of radiation and viscous dissipation effects. It is assumed that the viscous fluid is gray, absorbing-emitting radiation but a non-scattering medium. The Boussinesq approximation and Rosseland approximation are employed. The analytic expressions for temperature and velocity profiles are obtained and the effects of the permeability of the porous substrate, Grashof number, conduction-radiation parameter (stark number), and perturbation parameter on the flow and temperature fields and in the Nusselt number have been discussed.