摘要
针对冻结法应用中的单管冻结相变热传导问题,考虑土性参数空间上的变异性,将土体传热区域的导热系数和体积比热容模拟为随机场,基于随机场局部平均理论,采用Neumann展开Monte-Carlo随机有限元法对单管冻结随机温度场求解进行了分析,给出了有限元节点温度响应的均值与方差计算公式,根据计算流程框图编写了求解单管冻结温度场的Matlab随机有限元计算程序。通过算例,得到了考虑土性参数不确定的单管冻结温度场统计分布规律,并与将各随机参数视为单一随机变量的情况进行了对比。结果表明:随机场及其局部平均理论能合理考虑土性热学参数空间上的不确定性;土性热学参数模拟为随机场和随机变量获得的温度均值分布规律基本相同;模拟为随机变量得到的温度场变异性偏高,采用随机场建模方法显得更加科学合理。
For the freezing process induced by single freezing pipe during the application of artificial ground freezing technique,considering spatial variability of soil parameters,by modeling the heat transfer coefficient and specific heat capacity as spatially random fields,an analysis to calculate the temperature field around a single freezing pipe was made by the Neumann expansion Monte-Carlo method based on the local average theory of random field. The computational formulas of mathematical expectation and variance were given. According to the calculation flow block,the stochastic finite element calculation program for solving the temperature field around a single freezing pipe was written by the matrix laboratory. An example was presented in order to demonstrate the effects of random field parameters on the temperature field around a single freezing pipe. These results were compared with the results which are derived when the permeability tensor is only dealt with random variable. The results show that local average random field theory can consider the variability of soil parameters reasonably. The distribution of mean temperature is basically same when the heat transfer coefficient and specific heat capacity are modeled as spatially random fields and random variables. It will be overestimate the variability when simulate thermal parameters around a single freezing pipe as random variables.Therefore,the method based on random field theory is more scientific and reasonable.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2014年第6期1063-1069,共7页
Journal of China Coal Society
基金
国家重点基础研究发展计划(973)资助项目(2012CB026103)
国家高技术研究发展计划(863)资助项目(2012AA06A401)
江苏省普通高校研究生科研创新计划资助项目(CXLX13_942)
关键词
参数变异性
单冻结管
温度场
随机有限元
variability of parameters
single freezing pipe
temperature field
stochastic finite element
