Stress-induced evolution of anisotropic thermal conductivity of dry granular materials

Jinhyun Choo, Young Jin Kim, Jung Hwoon Lee, Tae Sup Yun, Jangguen Lee, Young Seok Kim

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

Various factors, such as the volumetric fraction of constituents, mineralogy, and pore fluids, affect heat flow in granular materials. Although the stress applied on granular materials controls the formation of major pathways for heat flow, few studies have focused on a detailed investigation of its significance with regard to the thermal conductivity and anisotropy of the materials. This paper presents a numerical investigation of the stress-induced evolution of anisotropic thermal conductivity of dry granular materials with supplementary experimental results. Granular materials under a variety of stress conditions in element testing are analyzed by the three-dimensional discrete element method, and quantitative variations in their anisotropic effective thermal conductivity are calculated via the network model and conductivity tensor measurements. Results show that the directional development of contact area and fabric under anisotropic stress conditions leads to the evolution of anisotropy in thermal conductivity. The anisotropy induced in thermal conductivity by shear stress is higher than that induced by compressive stress because shear stress causes more significant changes in microstructural configurations and boundary conditions. The shear-stress-induced evolution of anisotropy between principal thermal conductivities depends on dilatancy as well as shearing mode, and the shear-driven discontinuity localizes the conductivity. Factors involved in the stress-induced evolution and their implications on the thermal conductivity characterization are discussed.

Original languageEnglish
Pages (from-to)91-106
Number of pages16
JournalActa Geotechnica
Volume8
Issue number1
DOIs
Publication statusPublished - 2013 Jan 1

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Granular materials
thermal conductivity
Thermal conductivity
Anisotropy
anisotropy
shear stress
Shear stress
heat flow
conductivity
Heat transfer
discrete element method
Mineralogy
dilatancy
material
Compressive stress
Shearing
Finite difference method
Tensors
fluid flow
discontinuity

All Science Journal Classification (ASJC) codes

  • Geotechnical Engineering and Engineering Geology
  • Earth and Planetary Sciences (miscellaneous)

Cite this

Choo, Jinhyun ; Kim, Young Jin ; Lee, Jung Hwoon ; Yun, Tae Sup ; Lee, Jangguen ; Kim, Young Seok. / Stress-induced evolution of anisotropic thermal conductivity of dry granular materials. In: Acta Geotechnica. 2013 ; Vol. 8, No. 1. pp. 91-106.
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Stress-induced evolution of anisotropic thermal conductivity of dry granular materials. / Choo, Jinhyun; Kim, Young Jin; Lee, Jung Hwoon; Yun, Tae Sup; Lee, Jangguen; Kim, Young Seok.

In: Acta Geotechnica, Vol. 8, No. 1, 01.01.2013, p. 91-106.

Research output: Contribution to journalArticle

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