### Abstract

This paper describes a three-dimensional random network model to evaluate the thermal conductivity of particulate materials. The model is applied to numerical assemblies of poly-dispersed spheres generated using the discrete element method (DEM). The grain size distribution of Ottawa 20-30 sand is modeled using a logistic function in the DEM assemblies to closely reproduce the gradation of physical specimens. The packing density and inter-particle contact areas controlled by confining stress are explored as variables to underscore the effects of micro- and macro-scales on the effective thermal conductivity in particulate materials. It is assumed that skeletal structure of 3D granular system consists of the web of particle bodies interconnected by thermal resistor at contacts. The inter-particle contact condition (e.g., the degree of particle separation or overlap) and the particle radii determine the thermal conductance between adjacent particles. The Gauss-Seidel method allows evaluation of the evolution of temperature variation in the linear system. Laboratory measurements of thermal conductivity of Ottawa 20-30 sand corroborate the calculated results using the proposed network model. The model is extended to explore the evolution of thermal conduction depending on the nucleation habits of secondary solid phase as an anomalous material in the pore space. The proposed network model highlights that the coordination number, packing density and the inter-particle contact condition are integrated together to dominate the heat transfer characteristics in particulate materials, and allows fundamental understanding of particle-scale mechanism in macro-scale manifestation.

Original language | English |
---|---|

Pages (from-to) | 991-998 |

Number of pages | 8 |

Journal | Computers and Geotechnics |

Volume | 37 |

Issue number | 7-8 |

DOIs | |

Publication status | Published - 2010 Nov 1 |

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### All Science Journal Classification (ASJC) codes

- Geotechnical Engineering and Engineering Geology
- Computer Science Applications

### Cite this

*Computers and Geotechnics*,

*37*(7-8), 991-998. https://doi.org/10.1016/j.compgeo.2010.08.007

}

*Computers and Geotechnics*, vol. 37, no. 7-8, pp. 991-998. https://doi.org/10.1016/j.compgeo.2010.08.007

**Three-dimensional random network model for thermal conductivity in particulate materials.** / Yun, Tae Sup; Evans, T. Matthew.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Three-dimensional random network model for thermal conductivity in particulate materials

AU - Yun, Tae Sup

AU - Evans, T. Matthew

PY - 2010/11/1

Y1 - 2010/11/1

N2 - This paper describes a three-dimensional random network model to evaluate the thermal conductivity of particulate materials. The model is applied to numerical assemblies of poly-dispersed spheres generated using the discrete element method (DEM). The grain size distribution of Ottawa 20-30 sand is modeled using a logistic function in the DEM assemblies to closely reproduce the gradation of physical specimens. The packing density and inter-particle contact areas controlled by confining stress are explored as variables to underscore the effects of micro- and macro-scales on the effective thermal conductivity in particulate materials. It is assumed that skeletal structure of 3D granular system consists of the web of particle bodies interconnected by thermal resistor at contacts. The inter-particle contact condition (e.g., the degree of particle separation or overlap) and the particle radii determine the thermal conductance between adjacent particles. The Gauss-Seidel method allows evaluation of the evolution of temperature variation in the linear system. Laboratory measurements of thermal conductivity of Ottawa 20-30 sand corroborate the calculated results using the proposed network model. The model is extended to explore the evolution of thermal conduction depending on the nucleation habits of secondary solid phase as an anomalous material in the pore space. The proposed network model highlights that the coordination number, packing density and the inter-particle contact condition are integrated together to dominate the heat transfer characteristics in particulate materials, and allows fundamental understanding of particle-scale mechanism in macro-scale manifestation.

AB - This paper describes a three-dimensional random network model to evaluate the thermal conductivity of particulate materials. The model is applied to numerical assemblies of poly-dispersed spheres generated using the discrete element method (DEM). The grain size distribution of Ottawa 20-30 sand is modeled using a logistic function in the DEM assemblies to closely reproduce the gradation of physical specimens. The packing density and inter-particle contact areas controlled by confining stress are explored as variables to underscore the effects of micro- and macro-scales on the effective thermal conductivity in particulate materials. It is assumed that skeletal structure of 3D granular system consists of the web of particle bodies interconnected by thermal resistor at contacts. The inter-particle contact condition (e.g., the degree of particle separation or overlap) and the particle radii determine the thermal conductance between adjacent particles. The Gauss-Seidel method allows evaluation of the evolution of temperature variation in the linear system. Laboratory measurements of thermal conductivity of Ottawa 20-30 sand corroborate the calculated results using the proposed network model. The model is extended to explore the evolution of thermal conduction depending on the nucleation habits of secondary solid phase as an anomalous material in the pore space. The proposed network model highlights that the coordination number, packing density and the inter-particle contact condition are integrated together to dominate the heat transfer characteristics in particulate materials, and allows fundamental understanding of particle-scale mechanism in macro-scale manifestation.

UR - http://www.scopus.com/inward/record.url?scp=78349306612&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=78349306612&partnerID=8YFLogxK

U2 - 10.1016/j.compgeo.2010.08.007

DO - 10.1016/j.compgeo.2010.08.007

M3 - Article

AN - SCOPUS:78349306612

VL - 37

SP - 991

EP - 998

JO - Computers and Geotechnics

JF - Computers and Geotechnics

SN - 0266-352X

IS - 7-8

ER -