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Mixed convection heat transfer in porous media in the non‐darcy regime
Author(s) -
Islam Rafiqul M.,
Nandakumar K.
Publication year - 1988
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450660110
Subject(s) - grashof number , prandtl number , darcy number , porous medium , heat transfer , combined forced and natural convection , mechanics , thermodynamics , convective heat transfer , forced convection , convection , film temperature , darcy's law , reynolds number , natural convection , materials science , nusselt number , physics , rayleigh number , porosity , turbulence , composite material
In this study mixed convection heat transfer in a homogeneous porous duct of square cross section in a horizontal orientation is examined. Results from a generalized Forchheimer model are compared with that from the Darcy model. The heat transfer rate and the flow behavior depend on the following parameters: Grashof number, Gr = Q'gβKa/kv 2 , an axial flow pressure drop parameter, ζ = (aK/vμ)dp'/dz' , an inertial parameter ξ = mK/a , appearing in the Forccheimer model and the Prandtl number, Pr = C p μ/k. In the Darcy limit, ξ → 0, the role of the axial flow parameter, λ is reduced to a mere scale factor and the flow behavior is determined by a single parameter, λ = Gr · Pr. Both the Darcy and the Forchheimer models exhibit dual solutions and a hysteresis behavior over a certain range of Gr. Such parametric dependence can be used as an additional tool along with carefully designed experiments to determine the importance of inertial and Prandtl number effects on convective heat transfer in porous media.