笛卡尔切割单元法在湖泊二维流场模拟中的应用

针对湖泊几何边界复杂的特点,为了高效并准确地计算流场,采用了基于有限体积法的笛卡尔切割单元法.该方法在流场主要区域采用笛卡尔网格,而对与固体边界相交处的单元采用特殊的处理.这样既保留了笛卡尔网格求解速度快的优点,同时在边界处又保证了精度,避免了传统差分法处理该类问题需采用阶梯形网格逼近而导致的失真问题.通过与一个标准算例的贴体网格计算结果对比,显示计算结果一致.最后运用笛卡尔切割单元法,求解了杭州西湖的二维流场,结果表明该方法适用于具有复杂几何边界的湖泊流场求解,且精度较高.

Application of Cartesian Cut Cell Method to Simulation of the 2D flow in a Lake

As to the complexity of lake's geometry boundary,Cartesian cut cell method based on finite volume method is adopted to solve the flow field efficiently and accurately.The method uses Cartesian grid for the majority of flow field with special treatment to cells cut by the solid boundary,thus not only retains the advantage of Cartesian grid's high solving speed,but also ensures the high precision near the boundary,which avoids the distortion coming from scalariform mesh with traditional difference method.Compared with a standard case solved by body fitted coordinates,a high computational accuracy is verified.At last,this method is applied to simulation of the two dimensional flow in West Lake in Hangzhou,and the result indicates its ability to solve the flow of a lake which has a complex boundary condition.