DIRECT SIMULATION OF FORCED CONVECTION FLOW IN A PARALLEL PLATE CHANNEL FILLED WITH POROUS MEDIA

In this study the flow field and heat transfer properties of a steady, two-dimensional flow field in a porous domain between two parallel plates is investigated numerically by using a discretized numeric code. Analysis has been carried for Reynolds number based on particle sizes ranging from 60 to 1000. Numerical results are compared with different numerical methods used for predicting this kind of flow. Results are obtained for different regime, various Rep numbers and the effect of Particles size is also investigated. Solutions indicate that by increasing the Rep, the flow in the porous media remains laminar where the flow has turbulence characteristics for Rep <50. Moreover, by increasing Rep, the value of average Nusselt number increases. Also, reducing the particle size affects the Nusselt number and it increases while the porosity remains the same.

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Experimental Investigation of the Ice-Formation in a Planar Nozzle With Forced Convection Flow

Heat Transfer: Volume 2 ◽

10.1115/ht2005-72062 ◽

2005 ◽

Cited By ~ 2

Author(s):

B. Weigand ◽

S. Zehner ◽

A. Knapp ◽

R. Braun

Keyword(s):

Experimental Investigation ◽

Layer Thickness ◽

Parallel Plate ◽

Reynolds Numbers ◽

Ice Formation ◽

Axial Position ◽

Convection Flow ◽

Flow Acceleration ◽

Forced Convection Flow ◽

Plate Channel

The present paper deals with the ice-formation in a planar nozzle with a convergence angle of 2.5 deg. First experiments have been carried out for different wall cooling parameters B in the range between 4 to 18 and for different flow rate Reynolds numbers in the range of 5000 < Re4h < 46000. For all these experiments only smooth ice-layers could be observed. However, in a cooled parallel plate channel or a diffuser, normally wavy ice-layers are observed for the parameter range reported above. This interesting result can be seen as a first justification for the hypothesis (which has been stated in literature) that the formation of wavy ice-layers is caused by flow laminarisation (due to the rapid growth in ice-layer thickness with increasing axial position from the inlet) and retransition to the fully turbulent state (after the ice-layer thickness reaches a nearly constant value). Thus, wavy ice-layers might be suppressed by superimposing flow acceleration.

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Local Thermal Non-Equilibrium Effect in Forced Convection of Non-Newtonian Fluids Through Porous Media

Volume 2, Parts A and B ◽

10.1115/ht-fed2004-56649 ◽

2004 ◽

Author(s):

S. A. Khashan

Keyword(s):

Porous Media ◽

Forced Convection ◽

Numerical Solutions ◽

Thermal Conductivity Ratio ◽

Convection Flow ◽

Lower Fluid ◽

Flow Through ◽

Forced Convection Flow ◽

Resistance Coefficients ◽

Non Equilibrium

In this paper, we examine the effect of local thermal non-equilibrium LTNE condition on the non-Newtonian forced convection flow through channels filled with porous media. Four representative dimensionless parameters are used in formulating the problem. Numerical solutions obtained over broad ranges of these parameters are utilized to map conditions at which local thermal non-equilibrium condition is important, occurrence of LTNE is found to be driven by higher modified Peclet number, lower modified Biot number, lower fluid-to-solid thermal conductivity ratio, lower power-law fluid index, and lower microscopic and macroscopic frictional flow resistance coefficients. The proportional effect of each parameter as related to others is investigated.

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