正冻土水热迁移的移动泵模型  

A moving-pump model for moisture and heat transfer during soil freezing

作　　者：周家作[1] 韦昌富[1] 李东庆[2] 魏厚振[1] 

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071 [2]中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室,甘肃兰州730000

出　　处：《冰川冻土》2016年第4期1083-1089,共7页Journal of Glaciology and Geocryology

基　　金：国家重点基础研究发展计划(973计划)项目(2012CB026102);冻土工程国家重点实验室开放基金项目(SKLFSE201502)资助

摘　　要：通过引入脉冲函数将流量边界条件转化为源(汇)项,冻结锋面处的假想泵从未冻土中抽吸水分并储存在冻结锋面附近的狭窄区域.将水分扩散方程在整体求解域上等效分解为两个方程,避免了处理移动冻融边界的难题.在一个分解方程中引入汇项以表达未冻区水分的流出,在另一个分解方程中引入相同大小的源项以表达冻土中水分的聚集.将移动泵模型相关场方程和变量输入COMSOL M ultiphysics模拟软件的数学模块中,对一个封闭系统非饱和土冻结过程中水分和温度的变化过程进行了数值模拟,将模拟结果与前人试验和模拟结果进行了对比.The pulse function was used to transform the flux boundary condition into the source（ or sink） term.An imaginary pump located in the freezing front was sucking water from the frozen zone and storing it in a narrowtransition zone near the freezing front. The water diffusion equation was divided effectively into two equations in the whole solving domain to avoid the problem of dealing with the moving interface between frozen and unfrozen zone. A sink term was introduced in one dividing equation to express the discharge of water from the unfrozen zone and a source term was introduced in the other dividing equation to express the gathering of water in the frozen zone. The field equations and relations between variables were inputted into the mathematical module of the simulation software COMSOL Multiphysics to model a freezing test of an unsaturated soil sample in closed system,and the simulated results was compared with the experimental and simulated results performed by predecessors.

关 键 词：冻土 水热迁移 数值模拟 移动泵模型 

分 类 号：P642.14[天文地球—工程地质学]