Forced Convection in a Channel Filled With Porous Medium, Including the Effects of Flow Inertia, Variable Porosity, and Brinkman Friction

1987 ◽  
Vol 109 (4) ◽  
pp. 880-888 ◽  
Author(s):  
D. Poulikakos ◽  
K. Renken

This paper presents a series of numerical simulations which aim to document the problem of forced convection in a channel filled with a fluid-saturated porous medium. In modeling the flow in the channel, the effects of flow inertia, variable porosity and Brinkman friction are taken into account. Two channel configurations are investigated: parallel plates and circular pipe. In both cases, the channel wall is maintained at constant temperature. It is found that the general flow model predicts an overall enhancement in heat transfer between the fluid/porous matrix composite and the walls, compared to the predictions of the widely used Darcy flow model. This enhancement is reflected in the increase of the value of the Nusselt number. Important results documenting the dependence of the temperature and flow fields in the channel as well as the dependence of the thermal entry length on the problem parameters are also reported in the course of the study.

1987 ◽  
Vol 109 (3) ◽  
pp. 653-662 ◽  
Author(s):  
D. Poulikakos ◽  
M. Kazmierczak

This paper presents a theoretical study of fully developed forced convection in a channel partially filled with a porous matrix. The matrix is attached at the channel wall and extends inward, toward the centerline. Two channel configurations are investigated, namely, parallel plates and circular pipe. For each channel configuration, both the case of constant wall heat flux and constant wall temperature were studied. The main novel feature of this study is that it takes into account the flow inside the porous region and determines the effect of this flow on the heat exchange between the wall and the fluid in the channel. The Brinkman flow model which has been proven appropriate for flows in sparsely packed porous media and for flows near solid boundaries was used to model the flow inside the porous region. Important results of engineering interest were obtained and are reported in this paper. These results thoroughly document the dependence of the Nusselt number on several parameters of the problem. Of particular importance is the finding that the dependence of Nu on the thickness of the porous layer is not monotonic. A critical thickness exists at which the value of Nu reaches a minimum.


1996 ◽  
Vol 322 ◽  
pp. 201-214 ◽  
Author(s):  
D. A. Nield ◽  
S. L. M. Junqueira ◽  
J. L. Lage

We present a fresh theoretical analysis of fully developed forced convection in a fluid-saturated porous-medium channel bounded by parallel plates, with imposed uniform heat flux or isothermal condition at the plates. As a preliminary step, we obtain an ‘exact’ solution of the Brinkman-Forchheimer extension of Darcy's momentum equation for flow in the channel. This uniformly valid solution permits a unified treatment of forced convection heat transfer, provides the means for a deeper explanation of the physical phenomena, and also leads to results which are valid for highly porous materials of current practical importance.


2005 ◽  
Author(s):  
Liping Cheng ◽  
Andrey V. Kuznetsov

This paper investigates numerically heat transfer in a helical pipe filled with a fluid saturated porous medium. The analysis is based on the full momentum equation for porous media that accounts for the Brinkman and Forchheimer extensions of the Darcy law as well as for the flow inertia. Numerical computations are performed in an orthogonal helical coordinate system. The effects of the Darcy number, the Forchheimer coefficient as well as the Dean and Germano numbers on the axial flow velocity, secondary flow, temperature distribution, and the Nusselt number are analyzed.


2006 ◽  
Vol 129 (12) ◽  
pp. 1742-1747 ◽  
Author(s):  
Asterios Pantokratoras

In this paper, we study the steady laminar flow in a fluid-saturated porous medium channel bounded by two parallel plates with constant but unequal temperatures. One plate is moving with constant velocity while the other is stationary. For the porous medium, the Brinkman–Darcy–Forchheimer model is used. The investigation concerns engine oil, water, and air, taking into account the variation of their physical properties with temperature. The results are obtained with the direct numerical solution of the governing equations and cover large temperature differences. It is found that dynamic viscosity plays an important role on the results, which depart significantly from those of a fluid with constant properties when the temperature difference between the plates is large. Except that there are cases where the flow is restricted near the moving plate while at the lower part of the channel, the fluid is motionless.


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