scholarly journals Exact analytical solution for a thermal boundary layer in a saturated porous medium

2006 ◽  
Vol 19 (12) ◽  
pp. 1351-1355 ◽  
Author(s):  
E. Magyari ◽  
Emad H. Aly
Keyword(s):  
Boundary Layer ◽  
Porous Medium ◽  
Analytical Solution ◽  
Thermal Boundary Layer ◽  
Exact Analytical Solution ◽  
Saturated Porous Medium

Two-Phase Microscopic Heat Transfer Model for Three-Dimensional Stagnation Boundary-Layer Flow in a Porous Medium

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Ramesh B. Kudenatti ◽  
Shashi Prabha Gogate S.
Keyword(s):  
Boundary Layer ◽  
Porous Medium ◽  
Boundary Layer Flow ◽  
Thermal Boundary Layer ◽  
Solid Phase ◽  
Boundary Layer Equation ◽  
Three Dimensional ◽  
Fluid Phase ◽  
Transfer Model ◽  
Layer Flow

Abstract This work examines the steady three-dimensional forced convective thermal boundary-layer flow of laminar and incompressible fluid in a porous medium. In this analysis, it is assumed that the solid phase and the fluid phase, which is immersed in a porous medium are subjected to local thermal nonequilibrium (LTNE) conditions, which essentially leads to one thermal boundary-layer equation for each phase. Suitable similarity transformations are introduced to reduce the boundary-layer equations into system of nonlinear ordinary differential equations, which are analyzed numerically using an implicit finite difference-based Keller-box method. The numerical results are further confirmed by the asymptotic solution of the same system for large three-dimensionality parameter, and the corresponding results agree well. Our results show that the thickness of boundary layer is always thinner for all permeability parameters tested when compared to the nonporous case. Also, it is noticed that the temperature of solid phase is found to be higher than the corresponding fluid phase for any set of parameters. There is a visible temperature difference in the two phases when the microscopic interphase rate is quite large. The physical hydrodynamics to these parameters is studied in some detail.

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.

A self-similar solution of dissipative MHD for a jet in the boundary-layer approximation

1995 ◽  
Vol 53 (1) ◽  
pp. 49-62
Author(s):  
Alejandro G. Gonález ◽  
Martin Heyn
Keyword(s):  
Magnetic Field ◽  
Boundary Layer ◽  
Analytical Solution ◽  
Exact Analytical Solution ◽  
Viscous Drag ◽  
Integrals Of Motion ◽  
Boundary Layer Approximation ◽  
Initial Stage ◽  
Self Similar Solution ◽  
Self Similar

A solution of dissipative nonlinear MHD taking account of the balance between viscous drag, the Lorentz force, resistive diffusion and inertia in a boundary- layer approximation is presented. It is a steady solution corresponding to a jet in a conducting fluid with viscosity. The problem is solved using a self-similar variable. An exact analytical solution is possible. The integrals of motion are obtained and their physical meaning is explained. The behaviour of the solutions is described. The entrainment of the jet is observed in some examples after an initial stage dominated by magnetic fields. These solutions are an extension of Bickley's jet for a case with magnetic field and resistivity.

Sign in / Sign up

Export Citation Format

Share Document