文献类型：期刊文献

英文题名：Predicting the thermal conductivity of unsaturated soils considering wetting behavior: A meso-scale study

作者：Huang, Xian-Wen[1,2];Guo, Jia[3];Li, Kai-Qi[4,5];Wang, Ze Zhou[2];Wang, Wei[6]

机构：[1]Suzhou Univ Sci & Technol, Sch Civil Engn, Suzhou 215009, Jiangsu, Peoples R China;[2]Natl Univ Singapore, Dept Civil & Environm Engn, Singapore 117576, Singapore;[3]China Univ Geosci, Fac Engn, Dept Civil Engn & Mech, Wuhan 430074, Hubei, Peoples R China;[4]Wuhan Univ, Inst Engn Risk & Disaster Prevent, State Key Lab Water Resources & Hydropower Engn Sc, Wuhan 430072, Hubei, Peoples R China;[5]Hong Kong Polytech Univ, Dept Civil & Environm Engn, Hung Hom, Kowloon, Hong Kong, Peoples R China;[6]Shaoxing Univ, Sch Civil Engn, Shaoxing 312000, Zhejiang, Peoples R China

年份：2023

卷号：204

外文期刊名：INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER

收录：SCI-EXPANDED(收录号：WOS:000922441900001)、、EI(收录号：20230413440865)、Scopus(收录号：2-s2.0-85146651708)、WOS

基金：This work was supported by China Scholarship Council (No. 202108340062) , the National Natural Science Foundation of China (52174104 , 51778004)

语种：英文

外文关键词：Unsaturated soils; Meso-structure; Soil wetting; Hydrophilia; Thermal conductivity; Finite-element method

外文摘要：Unsaturated soils are three-phase porous materials that consist of the solid phase, the liquid phase and the gas phase. While accurate predictions to the thermal conductivity of unsaturated soils are crucial for the analysis and design of geothermal systems, the distribution characteristics of the different phases can also significantly affect the thermal performance. In addition, the fact that soils are heterogeneous materials also adds to the challenges in the evaluation of the thermal conductivity of unsaturated soils. In this paper, a methodology is proposed to calculate the thermal conductivity of unsaturated soils. This methodology starts from identifying representative soil parameters based on microscopy images of soil specimens. The meso-structures that consist of the different phases are then reconstructed in a finiteelement model based on the identified characteristics. The Monte-Carlo-based finite-element analyses are then carried out to calculate the thermal conductivity of unsaturated soils while considering the wetting behavior between the solid and liquid phases, which is characterized using the hydrophilia coefficient. After validating the methodology using both the experimental and numerical results reported in the literature, a parametric analysis is conducted. The results indicate that a high quartz content improves the heat transfer, but the quartz content does not affect the heat transfer skeleton. Furthermore, an increase in the solid content and degree of saturation results in an increase in the density of the heat transfer skeleton, which leads to enhanced heat transfer efficiency. A reduction in the hydrophilia coefficient and the formation of liquid-bridges have a similar effect. Last, the effects of wetting are more evident in soils with high porosity and a low degree of saturation.