透平叶片内部结构的低周疲劳寿命优化设计

Optimization Design of Low Cycle Fatigue Life of Turbine Blade Internal Structure

透平叶片是燃气轮机寿命设计的关键部件,其内部复杂的冷却结构直接影响甚至制约透平叶片的低周疲劳寿命。为此,针对某型燃气轮机透平静叶中的内部扰流结构,基于整体模型的分析结果,应用子模型方法构建局部分析模型,通过对比边界路径上的应力结果确定用于优化设计的基准模型方案,最后分析了3种不同倒圆半径方案的应力和低周疲劳寿命,并与初始方案结果进行对比,结果表明随着扰流柱倒圆半径的增大,应力水平明显降低,低周疲劳寿命次数显著提升。同时,应用子模型方法对复杂模型的单个结构特征进行优化设计,得到的计算精度和效率比整体模型更高。研究成果能够为燃气轮机透平叶片结构设计分析提供指导。

Turbine blades are key components in the life design of gas turbines.The complex internal cooling structure directly affects or even restricts the low cycle fatigue life of turbine blades.Therefore,for the internal turbulent structure in a certain type of gas turbine,based on the analysis results of the overall model,the sub-model method is used to construct an analysis model,and the benchmark sub-model for optimization design is determined by comparing the stress results on the path of the sub-model boundary.Finally,the stress and low cycle fatigue life of three schemes with different fillet radiuses are analyzed,and are compared with the initial scheme results.The results show that as the fillet radius increases,the stress level is reduced and the number of low cycle fatigue increased significantly.At the same time,the application of the sub-model method can optimize the design of the single structural feature of the complex model,and the calculation accuracy and efficiency are higher than that of the overall model.The research result can provide guidance for the structural design and analysis of gas turbine blades.