Thermal radiation and heat generation/absorption effects on viscoelastic double-diffusive convection from an isothermal sphere in porous media

Abstract

Buoyancy-driven convective heat and mass transfer in boundary layer flow of a viscoelastic Jeffrey fluid from a permeable isothermal sphere embedded in a porous medium is studied. Thermal radiation flux and heat generation/absorption are also incorporated in the model. A non-Darcy drag force model is employed to simulate the effects of linear porous media drag and second order Forchheimer drag. The Rosseland diffusion algebraic approximation is utilized to simulate thermal radiation effects. The non-dimensionalized boundary layer equations are solved using implicit, finite-difference scheme. The influence of Darcy number (Da), Deborah number (De), ratio of relaxation to retardation times (λ), radiation parameter (F), Forchheimer inertial parameter (Λ) and heat generation/absorption parameter (Δ), on normalized velocity, temperature, concentration, skin friction, heat and mass transfer rates are also studied. The present study has applications in the storage of nuclear waste materials.

Keywords

• Non-Newtonian Jeffreys fluid
• Rosseland thermal radiation model
• Isothermal sphere
• Keller-box numerical method
• non-Darcy flow
• Porous media