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在工程实际中 ,燃气轮机、汽轮机的叶轮在结构上呈现周期旋转对称性 .在对此类结构采用有限元法进行振动特性分析时 ,由于叶片与轮盘的几何形状复杂 ,叶片数目又多 ,满意的有限元模型计算规模非常大 .根据叶轮结构的旋转对称特性 ,引入映射理论和傅里叶级数展开理论 ,把有限元分析模型的区域局限于一个基本重复扇区之内 ,使求解规模大大降低 ,有效地提高计算效率、节约机时 .文中给出了 2个算例 ,计算结果表明该方法是行之有效的 ,对叶片数目较多 ,结构比较复杂的叶轮结构特别适用
In engineering practice, the impellers of gas turbines and steam turbines exhibit periodic rotational symmetry in structure.When the finite element method is used to analyze the vibration characteristics of such structures, due to the complex geometry of blades and disks, Based on the rotational symmetry characteristics of the impeller structure, the introduction of the mapping theory and Fourier series expansion theory, the finite element analysis of the limited area of the model within a basic repetitive sector, so that the solution is large scale Reduce and effectively improve the computational efficiency and save machine time.Two examples are given in the paper.The calculation results show that this method is effective and suitable for the impeller structure with more blades and more complicated structures