叶片动应力计算的重要改进及其在不调频叶片设计上的应用

Important Improvement of the Calculation in the Blade Dynamic Stress and Aplication of the Design in the Blades of the Various Stages

叶栅流场中的叶片受流道中汽流力的作用 ,同时也承受了流道中谐波汽流力的激振。由于谐波汽流力沿周向波动 ,其对叶片的激振力应该是流道宽度内谐波激振力的积分。本着这一观念对 ASME早期发表的动应力基本方程进行改进 ,重新作了推导 ,并指出了降低叶片共振应力的途径。多年来已取得了成功应用 ,其中涉及带冠单叶片的动强度特性及不调频叶片事故处理的材料综合抗振强度对比分析 ,对工程实践具有一定的参考借鉴的价值。图 3表 1参

Since the blade in the cascade flow field is effected by the steam power in the flow passage, meanwhile, bears the excitation of harmonic steam force in the flow passage, with the harmonic steam power fluctuating along the circumference, the exciting force on the blade should be integral of harmonic exciting force within the flow passage width. In line with this concept, the author improves the fundamental equation of dynamic stress that ASME published early, derives again, and point out the gateway to reducing the resonance stress of the blade. This application has succeeded over the years, especially the opposite analysis of materiasl comprehensive vibration strength, related to the dynasmic strength performance of the coronal single impeller and the trouble removal on the blade with the unregulated frequency, possesses the reference in the engineering practice. Figs 3, table 1 and refs 6.