全气膜覆盖掠叶片的几何成型与网格生成技术

Geometrical Configuration of Full-size Air-film Cooling of Swept Blades and Grid Generation Techniques

详细描述了全尺寸的气膜冷却扭叶片的几何生成技术和复杂结构化网格生成技术,对于气膜冷却几何结构的生成,要遵循由基础到复杂、由粗到精的原则,得到基础的冷却部件后再进行详细的冷却布局划分,冷却腔的形成用片体切割要比直接生成实体更容易实现。给出了全结构化网格拓扑结构在气膜冷却结构中的详细划分过程,列出了结构化和非结构化网格对于气膜冷却计算的优点和缺点。网格的划分都遵循由底至顶、逐层分割的方式,冷气柱部分的网格要在腔体划分基础上利用顶点网格块构造法生成。对于弯扭叶片而言,展向高度大致相近的冷却孔层要尽量切割到相同的层内,才不至于使网格划分线过分密集;由于几何结构制约性产生低质量网格的部分,通过调整网格数量占到整个网格总数的极少数,对于仿真计算没有影响。

A relatively detailed description was given of the geometrical generation technology and complicated structured grid generation technique for full-size air-film cooled twisted blades.With respect to the generation of air-film cooling geometrical structures,the principle of development from a base level to complexity and from crudity to refinement should be followed.A detailed cooling configuration division shall be conducted only after the basic cooling parts have been identified.The formation of cooling cavities by cutting into slices is more easily realized than by a direct generation of entities.A detailed division process of a wholly structured grid topological structure in the air-film cooling design was given,and the merits and demerits of structured and non-structured grids for air-film cooling calculation were listed.The division of grids shall follow the procedure of from the bottom to the top and employing a layer-by-layer cutting mode.The grid of the cold air column portion should be generated by using an apex grid block construction method on the basis of cavity division.For bowed and twisted blades,the cooling hole layers at an approximately same blade height should be cut into a same layer to a maximally possible extent so that the grid division lines are not grouped too densely.The portion of low quality grid,resulting from the restriction of geometrical structure,shall occupy a minimum quantity of the grid total amount by adjusting the grid number.The above process does not affect the simulation calculation.