Effect of Double Stratification on Free Convection in a Darcian Porous Medium

2004 ◽  
Vol 126 (2) ◽  
pp. 297-300 ◽  
Author(s):  
P. V. S. N. Murthy ◽  
D. Srinivasacharya and ◽  
P. V. S. S. S. R. Krishna
Keyword(s):  
Porous Medium ◽  
Free Convection ◽  
Vertical Surface ◽  
Function Form ◽  
Double Stratification ◽  
Flow Temperature ◽  
Complex Interactions ◽  
Free Convection Heat ◽  
Buoyancy Ratio ◽  
Darcy Rayleigh Number

The problem of free convection heat and mass transfer from vertical surface embedded in a doubly stratified porous medium has been studied. The similarity solution is presented for the case of uniform heat and mass flux conditions when the thermal and solutal stratification of the medium are assumed to have the power function form x1/3. The flow, temperature and concentration fields are effected by the complex interactions among the diffusion ratio parameter Le and buoyancy ratio parameter N in addition to the flow driving Darcy-Rayleigh number Rax. The temperature and concentration profiles are effected due to double stratification of the medium and its effect on the Nusselt and Sherwood numbers is discussed.

Free Convective Heat and Mass Transfer in a Doubly Stratified Non-Darcy Porous Medium

2006 ◽  
Vol 128 (11) ◽  
pp. 1204-1212 ◽  
Author(s):  
P. A. Lakshmi Narayana ◽  
P. V. S. N. Murthy
Keyword(s):  
Mass Transfer ◽  
Porous Medium ◽  
Heat And Mass Transfer ◽  
Convective Heat ◽  
Vertical Direction ◽  
Vertical Surface ◽  
Transfer Coefficients ◽  
Double Stratification ◽  
Complex Interactions ◽  
Inertia Parameter

Free convective heat and mass transfer from a vertical surface embedded in a doubly stratified non-Darcy porous medium has been analyzed. The wall temperature and concentration are constant and the medium is linearly stratified in the vertical direction with respect to both temperature, and concentration. A series approximation is made for stream function, temperature, and concentration in terms of the stratification parameter. The flow, temperature, and concentration fields are affected by the complex interactions among the diffusion ratio Le, buoyancy ratio N and stratification ratio Sr in addition to the inertia parameter Fc. The effect of double stratification of the medium on nondimensional heat and mass transfer coefficients is discussed.

DOUBLE DIFFUSIVE FREE CONVECTION ALONG A VERTICAL SURFACE IN A DOUBLY STRATIFIED POROUS MEDIUM WITH SORET AND DUFOUR EFFECTS UNDER MHD FORCES

2017 ◽  
Vol 20 (10) ◽  
pp. 865-879
Author(s):  
S.V.S.S.N.V.G. Krishna Murthy ◽  
Frédéric Magoulès ◽  
B. V. Rathish Kumar ◽  
Vinay Kumar
Keyword(s):  
Porous Medium ◽  
Free Convection ◽  
Vertical Surface ◽  
Soret And Dufour Effects ◽  
Double Diffusive

scholarly journals Evaluation of radiation heat transfer in porous medial: Application for a pebble bed modular reactor cooled by CO2 gas

2013 ◽  
Vol 28 (2) ◽  
pp. 118-127
Author(s):  
Kamel Sidi-Ali ◽  
Khaled Oukil ◽  
Tinhinane Hassani ◽  
Yasmina Amri ◽  
Abdelmoumane Alem
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Free Convection ◽  
Radiation Heat Transfer ◽  
Convection Heat Transfer ◽  
Emergency Situation ◽  
System Of Equations ◽  
Radiation Heat ◽  
Pebble Bed ◽  
Free Convection Heat

This work analyses the contribution of radiation heat transfer in the cooling of a pebble bed modular reactor. The mathematical model, developed for a porous medium, is based on a set of equations applied to an annular geometry. Previous major works dealing with the subject have considered the forced convection mode and often did not take into account the radiation heat transfer. In this work, only free convection and radiation heat transfer are considered. This can occur during the removal of residual heat after shutdown or during an emergency situation. In order to derive the governing equations of radiation heat transfer, a steady-state in an isotropic and emissive porous medium (CO2) is considered. The obtained system of equations is written in a dimensionless form and then solved. In order to evaluate the effect of radiation heat transfer on the total heat removed, an analytical method for solving the system of equations is used. The results allow quantifying both radiation and free convection heat transfer. For the studied situation, they show that, in a pebble bed modular reactor, more than 70% of heat is removed by radiation heat transfer when CO2 is used as the coolant gas.

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