The heat and mass transfer characteristics of natural convection about a truncated cone embedded in a saturated porous medium subjected to the coupled effects of thermal and mass diffusion is numerically analyzed. The surface is maintained at variable wall temperature/concentration (VWT/VWC) or variable heat/mass flux (VHF/VMF). The transformed governing equations are solved by Keller box method. Numerical data for the dimensionless temperature profiles, the dimensionless concentration profiles, the local Nusselt number and the local Sherwood number are presented for wide range of dimensionless distance ξ, the Lewis number Le, the exponent λ, and buoyancy ratioN (orN*). In general, it has been found that when the buoyancy ratio is increasing both the local Nusselt number and the local Sherwood number increase. Increasing the value of λ and ξ increases the local surface heat and mass transfer rates. The local Nusselt (Sherwood) number increases (decreases) with decreasing the Lewis number. Furthermore, it is shown that the local Nusselt number and the local Sherwood number of the truncated cone approach those of inclined plate (full cone) for the case of ξ=0 (ξ→∞).

Coupled heat and mass transfer by free convection over a truncated cone in porous media: VWT/VWC or VHF/VMF

Natural convection heat and mass transfer near a vertical wavy surface with constant wall temperature and concentration in a porous medium

The study of hydromagnetic heat and mass transfer in MHD flow of an incompressible, electrically conducting, viscous fluid past an infinite vertical porous plate along with porous medium of time dependent permeability under oscillatory suction velocity normal to the plate has been made. It is considered that the influence of the uniform magnetic field acts normal to the flow and the permeability of the porous medium fluctuate with the time. The problem is solved, numerically by Galerkin finite element method for velocity, temperature, concentration field and the expressions for skin – friction, Nusselt number and Sherwood number are also obtained. The results obtained are discussed for Grashof number (Gr > 0) corresponding to the cooling of the plate and (Gr < 0) corresponding to the heating of the plate with the help of graphs and tables to observe the effects of various parameters.

Finite element solution of heat and mass transfer in mhd flow of a viscous fluid past a vertical plate under oscillatory suction velocity

An integral approach for heat and mass transfer by natural convection from truncated cones in porous media with variable wall temperature and concentration

The Forchheimer free convection heat and mass transfer near a vertical surface embedded in a fluid saturated porous medium has been analyzed. A similarity solution is presented for constant wall temperature and concentration distributions with specified power function form (Ax−1/2) of mass flux parameter. The effect of Grashof number (Gr), the buoyancy ratio (N), the Lewis number (Le) and the surface mass flux (fw) on the nondimensional heat and mass transfer coefficients are presented.

Heat and mass transfer by natural convection in a non-Darcy porous medium

This study deals with free convection heat and mass transfer from a vertical plate embedded in a fluid saturated porous medium with constant wall temperature and concentration. The temperature and concentration variations across the boundary layer produce a buoyancy effect which gives rise to flow field. Integral method of Von-Karman type is applied to obtain the analytical solution of this fundamental problem.

Queeny

Papers

Free convection heat and mass transfer along a vertical surface in a porous medium