基于管径指数分布的毛细管束模型

A capillary bundle model based on aperture's exponential distribution

岩土类孔隙介质的渗透性及其随外部物理化学环境的改变而变化的性质对于各类工程而言是非常重要的,然而至今多数描述上述性质的理论多是基于唯象学观点,无法从本质上解释此类材料的渗流本质特性及其随环境而改变的性质.在前人总结的孔隙数量随孔径大小呈指数分布的基础上,在不改变函数数学特性的前提下对其进行调整,使之严格符合数学分布函数的要求,并在此基础上建立了一个用于描述孔隙介质细观渗流特征的变孔径毛细管束模型.运用该模型从理论上探讨了水温对渗流的影响、达西定律上限、超限后流量计算及孔隙率对渗流影响等问题,最后通过实例计算了孔隙介质的渗透系数和临界水力梯度,并对相关结果进行了分析.

The permeability and its changing characters in physicochemical environment of porous media like rock and soil are very important for all kinds of civil engineering projects.But until to now,most theories about this problem were based on a phenomenological method,which can not essentially display the innate character and variation properties of fluid seepage in porous media induced by the changing of environment.Based on the hypothesis that the pore number follow exponential distribution with pore radius,rectified the gamma without change its mathematical features,and fitted it for mathematic distribution function exactly,proposed a capillary bundle model for depicting the microscopic peculiarity of porous media＇s seepage.With this model,the effect of water temperature,the upper limit of Darcy Law,flow rate beyond Darcy Law＇s upper limit,and the infection of porosity on permeability etc issues were discussed theoretically.An instance was cited by the calculating of a permeability coefficient and the critical hydraulic gradient of China red sandstone,and the results were discussed.