利用三维接触有限元法的透平叶片枞树型叶根轮缘优化

采用三维接触有限元方法对透平叶片枞树型叶根轮缘结构进行了优化研究.以单个叶片为研究对象,采用零阶一阶算法、智能优化算法及模式搜索算法对叶根轮缘的7个特征尺寸进行了优化分析；结合实际工作状态,建立了3个叶片及轮缘的多变量优化模型,采用模式搜索算法对叶根轮缘结构进行了优化.结果表明:以单个叶片为例,在综合考虑优化精度和优化时间的情况下,模式搜索算法是解决叶根轮缘优化问题的最优方法；利用符合实际的模型可以得到能使叶根轮缘最大等效应力大幅度减小的优化结构,优化前后叶根和轮缘的最大等效应力位置基本不变,最大等效应力分别减小11.96％和21.63％.

Optimization for Turbine Blade with Fir-Tree Root and Rim by Three-Dimensional Contact Finite Element Method

The fir-tree root and rim of a turbine blade was optimized by the three-dimensional contact finite element method.A single blade model was adopted to optimize seven characteristic geometrical variables of the fir-tree root and rim by zero-order algorithm and first-order algorithm,intelligence optimization algorithm and pattern search algorithm.A multi-variable model with three blades and their rim which was considered to represent a more true working condition of turbine blades was established,and the structure of the blade root and rim was optimized by pattern search algorithm.The results show that pattern search algorithm is the best algorithm to solve this optimization problem in consideration of the accuracy and computation time according to the results of a single blade model optimization.The optimum structure which leads to significant decrease in the maximum equivalent stress of the blade root and rim can be obtained by using the model with three blades and their rim.Compared with the original design,the position of the maximum equivalent stress of the blade root and rim changes slightly and the maximum equivalent stress of the blade root and rim decreases by 11.96% and 21.63%,respectively.