scholarly journals Discussion: “A Numerical Study of Thermal Dispersion in Porous Media” and “Numerical Determination of Thermal Dispersion Coefficients Using a Periodic Porous Structure”

2004 ◽  
Vol 126 (6) ◽  
pp. 1060-1061 ◽  
Author(s):  
Boming Yu
Keyword(s):  
Porous Media ◽  
Porous Structure ◽  
Numerical Study ◽  
Thermal Dispersion ◽  
Numerical Determination ◽  
Dispersion Coefficients

scholarly journals Laboratory Determination of Transverse and Longitudinal Dispersion coefficients in Porous Media

1996 ◽  
Vol 38 (1) ◽  
pp. 13-27 ◽  
Author(s):  
Makoto NISHIGAKI ◽  
Teddy SUDINDA ◽  
Y. SASAKI ◽  
M. INOUE ◽  
T. MORIWAKI
Keyword(s):  
Porous Media ◽  
Longitudinal Dispersion ◽  
Dispersion Coefficients ◽  
Laboratory Determination

scholarly journals Thermal Dispersion in Porous Media—A Review on the Experimental Studies for Packed Beds

2013 ◽  
Vol 65 (3) ◽  
Author(s):  
Türküler Özgümüş ◽  
Moghtada Mobedi ◽  
Ünver Özkol ◽  
Akira Nakayama
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Porous Media ◽  
Effective Thermal Conductivity ◽  
Experimental Studies ◽  
Experimental Methods ◽  
Packed Beds ◽  
Thermal Dispersion ◽  
Heat Addition

Thermal dispersion is an important topic in the convective heat transfer in porous media. In order to determine the heat transfer in a packed bed, the effective thermal conductivity including both stagnant and dispersion thermal conductivities should be known. Several theoretical and experimental studies have been performed on the determination of the effective thermal conductivity. The aim of this study is to review the experimental studies done on the determination of the effective thermal conductivity of the packed beds. In this study, firstly brief information on the definition of the thermal dispersion is presented and then the reported experimental studies on the determination of the effective thermal conductivity are summarized and compared. The reported experimental methods are classified into three groups: (1) heat addition/removal at the lateral boundaries, (2) heat addition at the inlet/outlet boundary, (3) heat addition inside the bed. For each performed study, the experimental details, methods, obtained results, and suggested correlations for the determination of the effective thermal conductivity are presented. The similarities and differences between experimental methods and reported studies are shown by tables. Comparison of the correlations for the effective thermal conductivity is made by using figures and the results of the studies are discussed.

Numerical Determination of Thermal Contact Resistance for Nonisothermal Forging Processes

2000 ◽  
Vol 122 (4) ◽  
pp. 776-784 ◽  
Author(s):  
A.-S. Marchand ◽  
M. Raynaud
Keyword(s):  
Thermal Properties ◽  
Finite Difference Method ◽  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Numerical Study ◽  
Thermal Contact ◽  
Numerical Determination ◽  
Predictive Capability ◽  
Interface Geometry

A numerical study is conducted to estimate the thermal contact resistance (TCR) between the tool and the workpiece during slow nonisothermal forging processes. A finite difference method is used to determine the TCR from a thermomechanical microscopic model. Correlations of the numerical results are developed for the TCR as a function of the interface geometry and the thermal properties. The method used to introduce these correlations in forging softwares, to account for a time and space-dependent TCR instead of a constant arbitrary value, is given. The predictive capability of the correlations is partially validated by comparing their outputs with TCR results from the literature. [S0022-1481(00)00903-8]

Determination of the Thermal Dispersion Coefficient During Radial Filling of a Porous Medium

2003 ◽  
Vol 125 (5) ◽  
pp. 875-880 ◽  
Author(s):  
Mylene Deleglise ◽  
Pavel Simacek ◽  
Christophe Binetruy ◽  
Suresh Advani
Keyword(s):  
Porous Media ◽  
Dispersion Coefficient ◽  
Resin Transfer Molding ◽  
Liquid Composite Molding ◽  
Thermal Dispersion ◽  
Transfer Molding ◽  
Thermoset Resin ◽  
Composite Molding ◽  
Fibrous Porous Media

Resin Transfer Molding is one of the Liquid Composite Molding processes in which a thermoset resin is infiltrated into a fibrous porous media in a closed mold. To reduce the curing time of the resin, the mold may be heated, influencing other filling parameters such as the resin viscosity. Analysis of the non-isothermal effects during filling will help to understand the manufacturing process. One of the issues of non-isothermal filling in porous media is the variation of the velocity profile at the micro scale level, which as it is averaged, cannot be included in the convective term. To account for it, the thermal conductivity tensor is modified and a thermal dispersion coefficient Kd is introduced to model the micro convection effects. In this paper, we explore the temperature profile under non-isothermal conditions for radial injection during Resin Transfer Molding in order to determine the thermal dispersion coefficient. An approximate solution is derived from the series solution and validated with a numerical method. Experiments using carbon fibers and polyester resin were conducted. The thermal dispersion coefficient is determined by comparing experimental results with the steady state analytical solution. The comparison between radial and linear injection results shows that the same degree of dispersion is present in isotropic fibrous porous media.

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