摘要
借鉴细观力学均质化思想,采用热电类比-集总参数法,在细观尺度建立了固流两相(干燥或饱和)岩土热导率预测正三棱柱-准内切球单元结构(Unit cell)模型,并基于34组文献试验数据和238组模型预测数据进行了对比分析。研究结果表明:①正三棱柱-准内切球单元结构在克服球、圆柱单元结构固有的空间修正缺陷同时,相对立方体-准内切球单元结构(孔隙率0.035~0.473)孔隙率适用范围扩展至0~0.6,可覆盖大部分天然岩土介质孔隙率范围;②MATLAB数据可视化显示正三棱柱-准内切球单元结构模型预测热导率随孔隙率增大呈凹形降低,低孔隙率(<0.2)岩土热导率预测结果偏低且趋向串联模型下限,高孔隙率(0.4~0.6)岩土热导率预测结果与试验测试值吻合度较高;③两相干燥状态下本模型相对其他单元结构模型预测效果更好,均方根误差RMSE和归一化均方根误差NRMSE最小,分别为0.89W/m·K和31%;④考虑岩土孔隙水形态和含量,提出的正三棱柱-准内切球单元结构可扩展应用于固液气三相非饱和状态,并基于孔隙颗粒结构、孔隙水形态提出进化视角下固液气多相组分和多孔颗粒结构主导的岩土热导率预测关联式单元结构模型研究的新思路。
Inspired by the homogenization theory in the field of micromechanics,a regular triangular prism-quasi-inscribed sphere unit cell model at the meso-scale for predicting the thermal conductivity of two-phase(dry or water-saturated)geomaterials is proposed by using the lumped parameter thermo-electric analogy method.The performance of the established model is evaluated with 34 sets of thermal conductivity experimental data and 238 sets of thermal conductivity predictions.The results indicated that:(1)The regular triangular prism-quasi-inscribed sphere unit cell is a real representative elementary volume that can characterize the macroscopic continuum geomaterials and overcome the inherent spatial correction defects of the sphere and cylinder unit cell structures.Besides,this model can be used for soil-rocks with the porosity of 0~0.6,covering most porosity range of the natural geomaterials.(2)The MATLAB data visualization illustrate that the proposed model gives thermal conductivities concavely decreasing with porosity,and the model performance is better at relative high porosity(0.3~0.6)than those at low void ratio(<0.25).(3)Taking the typical geomaterials under two-phase condition as an example,this model has better predictive performance than other unit cell theoretical models,especially under dry condition(the RMSE and NRMSE are,respectively,0.89W/(m.K)and 31%).(4)Finally,the unit cell model proposed herein can be extended to three-phase unsaturated state(general solid-liquid-gas),and a promising initiative,i.e.,to study the effects of component and structure on the effective thermal conductivity of porousgranular geomaterials from an evolutionary perspective,is conjectured based on pore/particle structure and pore water morphology,aiming to provide a new way for further investigating the macroscopic thermo-mechanical behavior of tanglesome geomaterials.
作者
褚召祥
王一鸣
李晓昭
董凯军
顾晓滨
贾国圣
CHU Zhaoxiang;WANG Yiming;LI Xiaozhao;DONG Kaijun;GU Xiaobin;JIA Guosheng(School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou 221116,China;State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering,Xuzhou 221116,China;Yun Long Lake Laboratory,Xuzhou 221116,China;Guangzhou Institute of Energy Conversion,Chinese Academy of Science,Guangzhou 510640,China;School of Human Settlements and Civil Engineering,Xi'an Jiaotong University,Xi'an 710049,China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2024年第12期2580-2590,共11页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金项目(42107156,42230704)
111创新引智计划(B23003)
江苏省自然科学基金项目(BK20231501)
徐州市科技计划(KC23383)
广东省新能源和可再生能源研究开发与应用重点实验室开放基金项目(E039kf0501)。
关键词
岩土介质
表观热导率
孔隙率
关联式
演化
geomaterial
effective thermal conductivity
porosity
correlation
evolution
