【摘要】 为了进行冲击式水轮机的流动解析,基于非定常矢量三角形提出了静止系和旋转系时空同期离散的基本理论。选择静止系自由射流最内缘代表流线和旋转系水斗分水刃尖端轨迹圆弧的交点作为非定常相互作用的局部原点,两坐标系的位置用非定常矢量三角形联系在一起来进行时空同期离散。在任意时空同期离散单元,用非定常位移矢量三角形来计算两坐标系代表位置的变化,成功求出了时空同期离散单元两坐标系的平移。数值流动解析结果表明,静止系自由射流进入旋转水斗的坐标平移能够解决水膜间的干涉问题。这种解析方法利用CFD为冲击式水轮机水斗几何形状的优化设计提供有力技术支持。更多还原

【Abstract】 In order to execute the flow analysis for Pelton turbine,the basic theory of space-time synchronous discretization for stationary and rotating frames is proposed based on unsteady vector triangle. By choosing the cross point of inner-most representative streamline of stationary jet with the locus of rotating splitter tip of bucket as the local origin of unsteady interaction,the position in two frames is connected by the unsteady vector triangle for space-time synchronous discretization. In any discrete cartoon frame in space and time,the changes of position in two frames are calculated by the unsteady displacement vector triangle and the shift between two frames is obtained successfully. The results of the flow analysis reveal that the unacceptable numerical interference in the water sheets can be avoided by the unsteady frame shift between the stationary free jet and the rotating buckets. This analysis method provides a technical support to optimize the geometric design of Pelton’s buckets by CFD.更多还原