稳定流条件下土壤溶质运移两区模型的准解析解及数值模拟  

Quasi-analytical solution and numerical simulation for two-region model of solute transport through soils under steady state flow

作　　者：张德生[1] 沈冰[1] 沈晋[1] 王全九[1] 武新乾[1] 

机构地区：[1]西安理工大学,西安710048

出　　处：《水动力学研究与进展（A辑）》2004年第4期507-512,共6页Chinese Journal of Hydrodynamics

基　　金：国家自然科学基金资助项目(59879022);西安理工大学科技创新项目(108-210301)

摘　　要：　将弥散度概化为运移距离的指数函数,给出了稳定流条件下,非均质土壤中考虑水动力弥散尺度效应及不动水体存在时,一维溶质运移的两区模型。在初始浓度为零,半无限一维空间内定通量边界条件下,推导出了可动区和不动区溶质相对浓度的准解析表达式。用特征有限元法建立了相应的数值模型,从数值解和准解析解的计算数据可以看出:数值计算所产生的误差很小,能满足实际工作对计算精度的要求。A two-region model of 1-D solute transport through heterogeneous soils considering scale-dependent dispersion and immobile region under steady state flow is studied, and an quasi-analytical solution describing the concentration distribution in the mobile region and immobile region is deduced under zero initial concentration and constant flux boundary condition of a semi-infinite 1-D space. The numerical model of the two-region model is constructed by the characteristic finite element method. It can be seen from comparing the numerical solutions with the quasi-analytical solutions that the errors caused by the numerical computation are so small that the numerical model perfectly meets the demand of calculation precision in practical work.

关 键 词：两区模型 LAPLACE变换 准解析解 特征有限元法 

分 类 号：S153.5[农业科学—土壤学]