Effects of Surface Mass Transfer on Free Convection Flow Over Vertical Cylinder Embedded in a Saturated Porous Medium

1985 ◽  
Vol 107 (3) ◽  
pp. 394-396 ◽  
Author(s):  
M.-J. Huang ◽  
C.-K. Chen
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Porous Medium ◽  
Heat Transfer Coefficient ◽  
Free Convection ◽  
Saturated Porous Medium ◽  
Vertical Cylinder ◽  
Surface Mass ◽  
Surface Mass Transfer ◽  
The Heat Transfer Coefficient

The heat-transfer characteristics for free convection associated with isothermal vertical cylinder with surface mass transfer (blowing or suction) embedded in a saturated porous medium are analyzed. The nonsimilar equations are solved by using a suitable variable transformation and employing an implicit finite difference method. The numerical results for Nusselt number are expressed as functions of the parameters, ξ and γ, which represent the effects of the cylinder curvature and the surface mass transfer, respectively. It is found that the local Nusselt numbers for a vertical cylinder are less sensitive to the surface mass transfer than those for a vertical plate. Blowing of mass decreases the heat transfer coefficient but the suction of mass increases the heat transfer coefficient.

scholarly journals Darcy-Brinkman free convection about a wedge and a cone subjected to a mixed thermal boundary condition

1992 ◽  
Vol 15 (4) ◽  
pp. 789-794 ◽  
Author(s):  
G. Ramanaiah ◽  
V. Kumaran
Keyword(s):  
Heat Transfer ◽  
Boundary Condition ◽  
Heat Flux ◽  
Porous Medium ◽  
Heat Transfer Coefficient ◽  
Free Convection ◽  
Transformation Group ◽  
Darcy Number ◽  
Thermal Boundary Condition ◽  
High Porosity

The Darcy-Brinkman free convection near a wedge and a cone in a porous medium with high porosity has been considered. The surfaces are subjected to a mixed thermal boundary condition characterized by a parameterm;m=0,1,∞correspond to the cases of prescribed temperature, prescribed heat flux and prescribed heat transfer coefficient respectively. It is shown that the solutions for differentmare dependent and a transformation group has been found, through which one can get solution for anymprovided solution for a particular value ofmis known. The effects of Darcy number on skin friction and rate of heat transfer are analyzed.

Heat and Mass Transfer Processes and the Performance Evaluation in Single-Slope Solar Stills

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
David A. Aderibigbe
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Heat And Mass Transfer ◽  
Glass Cover ◽  
Transfer Processes ◽  
Mass Transfer Processes ◽  
Basin Water ◽  
The Heat Transfer Coefficient

The paper reviews the present understanding of the analysis of the heat and mass transfer processes in single-slope solar stills. By using the results of published experiments, it is proposed that the heat and mass transfer phenomena from the basin water to the glass cover are coupled. This coupling makes it possible to derive the dependence of the heat transfer coefficient for condensation on the inclination of the glass cover of the still. The derived relation, i.e., Nucon = 0.738 (Grcon*Prcon*sin β/Ja*)¼ A−1 where A is the aspect ratio, has been demonstrated to be an important expression for predicting the heat transfer coefficient for condensation hcon necessary for a more realistic evaluation of the overall efficiency of single-slope solar still of a given cover angle β.

scholarly journals Unsteady Three-Dimensional Mhd Flow Due to Impulsive Motion with Heat and Mass Transfer Past a Stretching Sheet in a Saturated Porous Medium

2013 ◽  
Vol 18 (1) ◽  
pp. 137-151 ◽  
Author(s):  
K. Rajagopal ◽  
P.H. Veena ◽  
V.K. Pravin
Keyword(s):  
Mass Transfer ◽  
Porous Medium ◽  
Saturated Porous Medium ◽  
Three Dimensional ◽  
Mhd Flow ◽  
Smooth Transition ◽  
Surface Shear Stress ◽  
Surface Shear ◽  
Surface Mass ◽  
Time Solution

The development of velocity, temperature and concentration fields of an incompressible viscous electrically conducting fluid, caused by impulsive stretching of the surface in two lateral directions and by suddenly increasing the surface temperature from that of the surrounding fluid in a saturated porous medium is studied. The partial differential equations governing the unsteady laminar boundary layer flow are solved analytically. For some particular cases, closed form solutions are obtained, and for large values of the independent variable asymptotic solutions are found. The surface shear stress in x and y directions and the surface heat transfer and surface mass transfer increase with the magnetic parameter and with permeability parameter and the stretching ratio, and there is a smooth transition from the short-time solution to the long-time solution.

Buoyancy Driven Flow in Saturated Porous Media

2006 ◽  
Vol 129 (6) ◽  
pp. 727-734 ◽  
Author(s):  
H. Sakamoto ◽  
F. A. Kulacki
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Boundary Layer ◽  
Mass Transfer ◽  
Porous Medium ◽  
Saturated Porous Medium ◽  
Saturated Porous Media ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Bulk Medium

Measurements are reported of heat transfer coefficients in steady natural convection on a vertical constant flux plate embedded in a saturated porous medium. Results show that heat transfer coefficients can be adequately determined via a Darcy-based model, and our results confirm a correlation proposed by Bejan [Int. J. Heat Mass Transfer. 26(9), 1339–1346 (1983)]. It is speculated that the reason that the Darcy model works well in the present case is that the porous medium has a lower effective Prandtl number near the wall than in the bulk medium. The factors that contribute to this effect include the thinning of the boundary layer near the wall and an increase of effective thermal conductivity.

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