地下水非稳定流的LTFAM算法

LTFAM METHOD FOR UNSTEADY FLOW OF GROUNDWATER

渗流域内应用拉普拉斯变换(LT)建立相应的有限分析(FAM)方程,顾及渗流域内地下水流的初始条件和边界条件,可在LT空间构成一个封闭的以水头像函数为变量的线性方程组。将此方程组所得的解,通过Stehfest数值反演公式,可归化为时间域的解(水头)。由于时间t被隐含在数值方程内,从而克服了传统数值法按时段(△t)逐步迭代的缺陷,提高了计算效率,也为用嵌入法建立地下水流管理模型提供了一条捷径。

This paper sets up FAM equation using LT in the flow domain,and gives consideration to the initial and boundary conditions of the flow domain. A close linear equation which take image of function of hydraulic head as variables are set up in LT space. After solving this linear equation in LT space,the solutions in the field of time are performed by using numerical inversion formula of stehfest. Because't' (time)is implicated in the numerical equations,the shortcomings of step-by -step iteration related to 't' (length of the time step)in the traditional numerical method are overcome, and the computation efficiency is raised. It also provides a shortcut to groundwater management modeling for embedding method.