摘要
在考虑相变的热能平衡方程和非饱和水分迁移质量控制方程的基础上,建立温度场-水分场的耦合模型,并采用一种无网格粒子算法(SPH)进行数值求解。其中,耦合方程中考虑了水流传热以及温度势对水流的直接驱动,在不考虑相变的情况下,该耦合模型可退化为常温下的水-热耦合模型,故可用于模拟冻融循环的相关问题。从求解热能平衡方程中的含冰量出发,实现解耦并对半无限单向冻结条件下介质内非稳态温度场和体积含水率分布场进行模拟,将耦合作用下的温度场与不耦合的解析解进行对比,反映出水分迁移对温度场存在较大影响。最后,求解了路基边坡在季节性周期温度边界下,温度场、水分场分布的演变规律,并评估了边坡阴阳面受热不均对水热两场分布的影响。计算结果基本能反映土冻结相变的实际物理过程,光滑粒子算法可以用于尝试解决冻土领域的其他相关问题。
Moisture-temperature coupling control equations are introduced into the heat and mass balance equation for the consideration of phase change. Smoothed Particle Hydrodynamics method is used to solve the equations, where both moisture transfer driven by temperature and heat transfer by water are considered. While the phase transition process is ignored, the model can directly degrade to a generic coupled model of moisture and heat at normal temperature. Therefore it can be used to study freezing and thawing cycle of frozen soils(e. g., seasonal or daily variation in ground temperature). To validate the model, the solution of a semi-infinite unsaturated porous medium subject to a frozen wall is studied. The comparison result shows that the process of moisture migration impacts on heat transfer, with the degree intensifying as time. In addition, the model is used in an unsaturated subgrade with periodical temperature boundary. The temperature and moisture distribution of subgrade are different when considering different solar radiation in sunny and shady slope. The evolution of water content field and thermal field is given at the end. Since the algorithm can basically reflect the real physical process of phase change, it’s credible to study other problems in the field of frozen soil by SPH method.
作者
饶登宇
白冰
陈佩佩
RAO Deng-yu;BAI Bing;CHEN Pei-pei(School of Civil Engineering,Beijing Jlaotong University,Beijlng 100044,China;School of Science,Beijing Universlty of Civil Engineering and Architecture,Beljing 102616,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2018年第12期4527-4536,共10页
Rock and Soil Mechanics
基金
国家自然科学基金资助项目(No.51478034,No.51678043)
北京建筑大学科学研究基金资助项目(No.KYJJ2017018)
supported by the National Natural Science Foundation of China(51478034,51678043)
the Beijing University of Civil Engineering and Architecture Research Foundation(KJJ2017018)
关键词
非饱和土
相变
水-热耦合
光滑粒子法
路基
unsaturated porous media
phase change
hydro-thermal coupling
SPH method
subgrade
