带冠叶片碰撞减振机理研究

A Study of Collisional Vibration-abatement Mechanism of Shrouded Blades

通过对带冠叶片边界非线性条件的研究,建立了全新的带有碰撞阻尼的叶片三维实体单元有限元模型。对计算分析与试验结果进行了对比,验证了叶片的计算模型的计算精度,进而对两只平板叶片在不同间隙、激振力幅值和频率条件下的特性进行分析,结果表明:随着叶冠间隙、激振力幅值和激振力频率的增加,叶片出现明显的频谱分量;具有碰撞条件的叶片可以抑制外力做功,叶片动应力可以通过叶冠参数的调整进行控制。

Through a study of non-linear boundary conditions of shrouded blades,established was a completely new three-dimensional entity-unit finite element model for the blades featuring collision damping. Through a calculation analysis and a comparison of test results,the computation accuracy of the model in question has been verified,and the characteristics of two flat blades,analyzed under the condition of different clearances,exciting force amplitudes and frequencies. The ensuing results show that with an increase of the shroud clearance,exciting force amplitude and frequency,the blades exhibit a conspicuous spectral component. The blades displaying collision conditions can suppress external forces to do work,making it possible to control the dynamic stress of the blades by adjusting the shroud parameters.