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

Combined effect of viscous dissipation and Joule heating on MHD forced convection over a non-isothermal horizontal cylinder embedded in a fluid saturated porous medium

UCM flow across a melting surface in the presence of double stratification and cross-diffusion effects

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

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.

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

Present investigation deals with natural convection heat transfer from a vertical plate embedded in a fluid saturated porous medium whose ambient temperature is not uniform The problem is solved by integral method of von-Karman type and the closed form solution is obtained The effects of stratification parameter on local and overall heat transfer coefficients, velocity and temperature profiles are analysed

Integral method to free convection in thermally stratified porous medium

Three-dimensional transient flow past a porous infinite plate is investigated when the suction velocity at the plate has the form

$$v_w (z) = v_0 \left[ {1 + \varepsilon \delta (t) cos\frac{{\pi z}}{l}} \right], \varepsilon<< 1$$

where

$$\begin{gathered} \delta (t) = 0, t 0. \hfill \\ \end{gathered} $$

Due to superimposed sinusoidal suction velocity ev0δ(t) cos πz/l, the flow becomes unsteady and three-dimensional. The Laplace transform technique is used to find the unsteady velocity distribution. The skin friction at the wall along the main and cross-flow directions is obtained. It is found that ast→∞ the values of skin friction tend to steady state values.

P. Singh

Papers

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

Integral method to free convection in thermally stratified porous medium

Transient three-dimensional flow along a porous plate