Porous media enclosure

Attention will here be restricted to two-dimensional steady flow in a rectangular porous medium -filled enclosure which is, in general, inclined at an angle to the vertical. One wall of the enclosure is kept at a uniform high temperature and the opposite wall is kept at a uniform low temperature. The o her two walls of the enclosure are assumed to be adiabatic, i.e., it is assumed that no heat is transferred into or out of these walls. The situation is, therefore, as shown in Fig. 10.27. 

Explain how the computer program for the calculation of flow in a porous medium-filled vertical enclosure given in this chapter must be modified to deal with the case where the heat flux rather than the temperature at the hot wall is specified. For this purpose, define the following dimensionless temperature ... 

An approximate model of the flow in a vertical porous medium-filled enclosure assumes that the flow consists of boundary layers on the hot and cold w alls with a stagnant layer between the two boundary layers, this layer being at a temperature that is the average of the hot and cold wall temperatures. Use this model to find an expression for the heat transfer rate across the enclosure and discuss the conditions under which this model is likely to be applicable. 

Bejan, A., On the Boundary Layer Regime in a Vertical Enclosure Filled with a Porous Medium", Lett. Heat Mass Transfer, Vol. 6, pp. 93-102, 1979. 

Naylor, D. and Oosthuizen, P.H., Free Convection in a Horizontal Enclosure Partly Filled with a Porous Medium . J of Thermophysics and Heat Transfer, Vol. 9, No. 4, pp. 797-800, 1995. 

Oosthuizen. P.H. and Paul, J.T.. "Natural Convection in a Rectangular Enclosure with a Partially Heated Wall and Partly Filled with a Porous Medium", Proc. Eighth Int. Conf. on Numerical Methods in Thermal Problems. Vol. VIII. Part I, Pineridge Press, Swansea, U.K., 1993, pp. 467-478. 

Oosthuizen. PH. and Naylor. D.. Natural Convective Heat Transfer from a Cylinder in an Enclosure Partly Filled w ith a Porous Medium, Ini. J. Sumer. L riiods Heat and Fluid Flow. Vol. 6, No. 6. pp. 51-63. 1996. 

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