Multiple slip and variable transport property effects on magnetohydromagnetic dissipative thermo-solutal convection in porous media

摘要

A mathematical study is presented to investigate the influence of variable transport properties and momentum, thermal and mass slip on magnetohydrodynamic (MHD)\udmomentum, heat and mass transfer in a porous media. Slip effects are simulated via careful imposition of boundary conditions at the wall. Joule heating and viscous\uddissipation are also studied. The governing partial differential boundary layer equations are analyzed using Lie group theory and rendered with appropriate transformations into a system of nonlinear, coupled ordinary differential equations. The multi-physical boundary value problem is dictated by twelve thermophysical parameters- concentration diffusivity\udparameter (Dc), Hartmann magnetic number (M), permeability parameter (omaga), Eckert number (Ec), momentum slip (a), thermal slip (b), mass (species) slip (d), Prandtl number (Pr), Schmidt number (Sc), power law index for non-isothermal and non-iso-solutal\udeffects (m), viscosity variation parameter (A) and thermal conductivity variation parameter (S). A numerical solution is obtained for the effects of selected parameters on transport characteristics using the robust Runge-Kutta-Fehlberg fourth-fifth order numerical quadrature method in Maple16. Excellent correlation is achieved between the present computational results and for the constant transport properties (A=S=Dc=0), nonporous (omega=0), non-thermal slip (b=0), non-solutal slip (d = 0) and non-dissipative solutions without Joule heating (Ec= 0) of Yazdi et al. [35]. Increasing momentum slip enhances temperatures whereas increasing thermal slip reduces them. An increase in thermal conductivity boosts temperatures whereas greater viscosity reduces temperatures. Increasing magnetic parameter suppresses velocity and increasing permeability parameter\udelevates temperatures. Species concentration is enhanced with increasing concentration diffusivity and permeability parameter but depressed with increasing viscosity. Furthermore concentration is enhanced with momentum slip but reduced with mass slip parameter. Moreover increasing magnetic field is observed to aid species diffusion in the regime. The present study finds applications in trickle-bed reactor hydromagnetics,\udmagnetic polymeric materials processing and MHD energy generator slip flows.