0
RESEARCH PAPERS: Porous Media

A Boundary Element Method for Evaluation of the Effective Thermal Conductivity of Packed Beds

[+] Author and Article Information
Jianhua Zhou1

School of Materials Science and Engineering, The University of New South Wales, Sydney, NSW 2052, Australia

Aibing Yu

School of Materials Science and Engineering, The University of New South Wales, Sydney, NSW 2052, Australia

Yuwen Zhang2

Department of Mechanical and Aerospace Engineering, University of Missouri-Columbia, Columbia, MO 65211zhangyu@missouri.edu

1

Current address: Dept. of Mechanical and AeroSpace Engineering, University of Missouri-Columbia, E2412 Lafferre Hall, Columbia, MO 65211.

2

Corresponding author.

J. Heat Transfer 129(3), 363-371 (Jun 06, 2006) (9 pages) doi:10.1115/1.2430721 History: Received December 09, 2005; Revised June 06, 2006

The problem of evaluating the effective thermal conductivity of random packed beds is of great interest to a wide-range of engineers and scientists. This study presents a boundary element model (BEM) for the prediction of the effective thermal conductivity of a two-dimensional packed bed. The model accounts for four heat transfer mechanisms: (1) conduction through the solid; (2) conduction through the contact area between particles; (3) radiation between solid surfaces; and (4) conduction through the fluid phase. The radiation heat exchange between solid surfaces is simulated by the net-radiation method. Two regular packing configurations, square array and hexagonal array, are chosen as illustrative examples. The comparison between the results obtained by the present model and the existing predictions are made and the agreement is very good. The proposed BEM model provides a new tool for evaluating the effective thermal conductivity of the packed beds.

FIGURES IN THIS ARTICLE
<>
Copyright © 2007 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Two-dimensional regular packing structure

Grahic Jump Location
Figure 2

Coordinate system and discretization of the boundaries

Grahic Jump Location
Figure 3

Geometries of the fluid-filled voids

Grahic Jump Location
Figure 4

Calculation of void fraction

Grahic Jump Location
Figure 5

Effect of particle number on the effective thermal conductivity

Grahic Jump Location
Figure 6

The temperature distributions in local regions for the case of square array (20 particles are used for simulation)

Grahic Jump Location
Figure 7

The temperature distributions in local regions for the case of hexagonal array (120 particles are used for simulation)

Grahic Jump Location
Figure 8

Comparison of the present model with previous theoretical models (square array, rp=2.5mm, rc∕rp=0.1, Tm=55°C)

Grahic Jump Location
Figure 9

Comparison of the calculating results with the previous predictions when radiation contribution is considered (square array, rp=2.5mm, rc∕rp=0.1, kf=0.029, ε=0.9)

Grahic Jump Location
Figure 10

The effective thermal conductivity for the square array and hexagonal array packings (Tm=55°C)

Grahic Jump Location
Figure 11

The effects of mean temperature and particle size on the effective thermal conductivity (ε=0.9)

Grahic Jump Location
Figure 12

The effect of solid surface emissivity on the effective thermal conductivity: (rp=2.5mm, rc∕rp=0.1, ks∕kf=600, Tm=1000°C)

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In