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Porous Natural Convection, underestimating Nusselt

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Old   August 8, 2007, 00:45
Default Porous Natural Convection, underestimating Nusselt
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Alex
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Dear Users,

Given: a 2D cavity filled with saturated porous medium.

BCs: Horizontal wall = Adiabatic; Vertical Wall = at constant tempereture (e.g., delta T=10C)

Flow Regime: Laminar

When compared to available experimental and numerical data, Nusselt obtained from my work is underestimated and is lower in a wide range of Rayleigh numbers.

Nusselt is calculated from Nu=Q_Convection/Q_Conduction.

Is it right to get Q_Convection from: Report menu>Fluxes>Heat Transfer and reciprocate the permeability of porous media to obtain viscous resistance.

Thank you in advance.
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Old   August 8, 2007, 14:52
Default Re: Porous Natural Convection, underestimating Nus
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red lemon
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In Nu=h.D/k, check the reference temp used in h, where Q=h/dT
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Old   August 9, 2007, 00:26
Default Re: Porous Natural Convection, underestimating Nus
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Alex
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1. Is there any difference between calculating Nu by Q_Convection/Q_Conduction and h.L/K? In porous media references the former is used instead of the latter.

2. In case of h.L/K, do I use the mass average temperature of porous media for the reference temperature? Does it correct the underestimation of Nu?
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