堤坝内流场和外流场的计算

Computations of Internal and External Flows on Dike

本文把堤坝的外流场和内流场看作一个整体问题，以Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ方程为流动控制方程，用ＶＯＦ法确定外流场的自由界面与内流场的浸润线，采用ＳＯＬＡ－ＶＯＦ方法进行数值求解．用堤坝内部细胞单元结构模型简化堤坝内部石块和空隙的复杂形状结构．为了验证上述数学计算模型的有效性，本文对梯形截面堤坝，在外界孤立波作用时，进行了堤坝外流场和内流场的计算，可以看到堤坝内压力场对堤坝的安全至关重要，同时还可以看到堤坝的内外压力场的脉动作用，是造成坝体破坏的重要因素．

A new model that is used to compute the internal and external flows of dikes is presented in this paper. In the model, the internal and external flows of dikes are taken into account as a whole and related problem in which the SOLAVOF method is used to solve the NavierStokes equations and determines the water free surface and wet lines in dikes. For simplicity, a molecular cell structure model for dikes is applied to replace the real complicated form of inner dikes. The computations is conducted for the cases that an incident solitary wave passes over an osmotic or nonosmotic dike with trapezoid section. Computational results cover the time evolution of the water free surface and wet lines in dikes, internal and external flow fields, and pressure on dikes. It is verified that internal flow fields and pressure in dike are very important for the safety design and operation of dikes.