二维高速碰撞问题欧拉数值模拟的混合网格计算

提出了适用于二维平面或轴对称多介质流体力学两步欧拉数值方法中输运计算的混合网格界面处理.在一个混合网格中,将界面近似看作直线.整个方法分为3步:①用混合网格周围的8个网格的介质面积份额确定界面的法线方向;②用混合网格的介质面积份额或体积份额确定界面的直线方程;③用此直线方程求出通过网格边界的流.给出了用此方法所做的测试、数值计算及与其它算法的比较.

Calculation of Mixed Cells in Simulating High-speed Collision Problems with Two-dimensional Eulerian Hydrodynamic Method

The algorithm proposed here can be used in 2D two-step plane and axisymmetric Eulerian hydrodynamic method to deal with the interface of a mixed cell. It takes advantage of the idea of Youngs method: in a mixed cell, the interface is regarded as a straight line. The area fraction of eight cells surrounding the mixed cell is used to determine the normal orientation of the interface, the area fraction or the volume fraction of the mixed cell is used to determine the equation (position) of the interface, and then the flux passing across the boundary of the cell according to this interface and the area fraction or the volume fraction of the cell at next time is calculated. In the last part of this report, some numerical results are presented, which include the precision tests of interface calculation, the comparison with SLIC and the calculations of comprehensive problems.