TY - JOUR
T1 - Numerical study of three-dimensional non-Darcy forced convection in a square porous duct
AU - Chen, G.
AU - Hadim, H. A.
PY - 1999
Y1 - 1999
N2 - The objective of the present work was to perform a detailed numerical study of laminar forced convection in a three-dimensional square duct packed with an isotropic granular material and saturated with a Newtonian fluid. Hydrodynamic and heat transfer results are reported for three different thermal boundary conditions. The flow in the porous medium was modeled using the semi-empirical Brinkman-Forchheimer-extended Dairy model which also included the effects of variable porosity and thermal dispersion. Empirical models for variable porosity and thermal dispersion were determined based on existing three-dimensional experimental measurements. Parametric studies were then conducted to investigate the effects of particle, diameter, Reynolds number. Prandtl number and thermal conductivity ratio. The results showed that channeling phenomena and thermal dispersion effects are reduced considerably in a three-dimensional duct compared with previously reported results for a two-dimensional channel. It was found that the Reynolds number affects mainly the velocity gradient in the flow channeling region, while the particle diameter affects the width of the flow channeling region. As the Reynolds number increases or as the particle diameter decreases (i.e., when the inertia and thermal dispersion effects are enhanced), the Nusselt number increases. The effects of varing the Prandtl number on the magnitude of the Nusselt number were found to be more significant than those of the thermal conductivity ratio. Finally, the effects of varing the duct aspect ratio on the friction factor can be neglected for small particle diameter (Dp ≤ 0.01) or for high particle Reynolds number (Red ≥ 1000) due to the dominant bulk damping resistance from the porous matrix (Darcy term) or strong inertia effects (Forchheimer term), respectively.
AB - The objective of the present work was to perform a detailed numerical study of laminar forced convection in a three-dimensional square duct packed with an isotropic granular material and saturated with a Newtonian fluid. Hydrodynamic and heat transfer results are reported for three different thermal boundary conditions. The flow in the porous medium was modeled using the semi-empirical Brinkman-Forchheimer-extended Dairy model which also included the effects of variable porosity and thermal dispersion. Empirical models for variable porosity and thermal dispersion were determined based on existing three-dimensional experimental measurements. Parametric studies were then conducted to investigate the effects of particle, diameter, Reynolds number. Prandtl number and thermal conductivity ratio. The results showed that channeling phenomena and thermal dispersion effects are reduced considerably in a three-dimensional duct compared with previously reported results for a two-dimensional channel. It was found that the Reynolds number affects mainly the velocity gradient in the flow channeling region, while the particle diameter affects the width of the flow channeling region. As the Reynolds number increases or as the particle diameter decreases (i.e., when the inertia and thermal dispersion effects are enhanced), the Nusselt number increases. The effects of varing the Prandtl number on the magnitude of the Nusselt number were found to be more significant than those of the thermal conductivity ratio. Finally, the effects of varing the duct aspect ratio on the friction factor can be neglected for small particle diameter (Dp ≤ 0.01) or for high particle Reynolds number (Red ≥ 1000) due to the dominant bulk damping resistance from the porous matrix (Darcy term) or strong inertia effects (Forchheimer term), respectively.
KW - Forced convection
KW - Porous medium
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U2 - 10.1108/09615539910256018
DO - 10.1108/09615539910256018
M3 - Article
AN - SCOPUS:0003865621
SN - 0961-5539
VL - 9
SP - 151
EP - 169
JO - International Journal of Numerical Methods for Heat and Fluid Flow
JF - International Journal of Numerical Methods for Heat and Fluid Flow
IS - 2
ER -