基于边界元法的渗流自由面计算

Calculation of Free Surface of Seepage Flow Based on the Boundary Element Method

自由面位置的确定是无压渗流计算的一个关键环节。求解这类问题的方法有固定网格法和移动网格法,但目前大部分都用固定网格法来解决自由面的位置问题,本文采用边界元通过移动网格法来求解自由面的位置问题,而在迭代过程中对溢出点采用二次插值的方法来确定。该方法思路清晰,易于编写程序,计算结果也比较精确,完全能够达到工程建设所要求的精度。

Determinating the location of the free surface is a key step in seepage flow calculation. There are two methods to solve these problems ：One is fixing-grid method, the other is changinggrid method. But most persons use the fixing-grid method to determinate the location of the free surface at present. In this paper, we use the boundary element method （BEM） and changing-grid method to determinate the location of the free surface, during the iteration process, using the quadratic interpolation to determinate the location of the outflow point. This method has the advantages as clear thought easy to programme, results with relative precise, so it can completely satisfy the need in engineering construction.