复杂急曲率变化水斗贴体坐标的曲面拟合

Discrete Analogue Curvature Fluctuating Widely Pelton Bucket Inner Surface by Body-Fitted Coordination

提出了用三维非正交贴体坐标系下的型值点描述水斗曲面的方法,同时对型值点进行了加密处理,实现了良好的水斗内曲面型值点的高密度均匀化拟合,推导了贴体坐标系下水斗曲面切向法向矢量计算公式,计算得到的切向、法向矢量更具有一贯性。

The inner surface of Pelton bucket is a free surface with cutout and the curvature fluctuating widely. The geometry eigenvalue for every data is necessary to analyze the free water sheets flow on inner bucket surface by CFD, but the Cartesian design data are inadequate. This paper presents the 3-D non- orthogonal Body-Fitted Coordinate system to discretize the free surface and achieve uniform high density grids. This paper deduces the tangential vector and unit normal vector equations for grid on 3-D Body-Fitted Coordinate system. The computed results on Body-Fitted coordination are more stable.