汽轮机带冠叶片阻尼振动特性的有限元分析

The Finite Element Analysis on Damping Vibration Dynamic Characteristics for Shrouded Blades of Steam Turbine

根据汽轮机叶片外形特点,在3D建模软件Solidworks中建立Z型叶冠单叶、成组叶片及整圈叶片的实体模型,通过ALGOR软件的机械运动仿真(MES)功能,计算带冠叶片组在不同冠间间隙、不同激励频率和幅值下的碰摩减振规律特性,并对所得结果进行分析。结果表明:通过冠间相互碰摩可有效减小叶片振动,当冠间间隙介于0.2 mm到0.5 mm之间时,碰摩减振效果最好;外部激振力对旋转产生的动应力影响较小,在特定的间隙值下,随激振力的变化叶片应力峰值变化较小。这些结论对汽轮机末级叶片的设计有重要的指导意义。

The solid models of single blade , grouped blade and whole circle blade with Z -shaped shroud are es-tablished in 3 D software Solidworks based on the features of steam turbine blade profile .By using the mechanical exercise simulation （ MES） functions of the ALGOR software , the laws of rub-impact vibration reduction char-acteristic for grouped blade under different shroud interval , different amplitude of exciting force and different fre-quency of exciting force were calculated , and the results analyzed .The study results showed that the blade vibra-tion is reduced by using shroud rub -impact structural, when the shroud interval between 0.2 mm to 0.5 mm, the rub-impact effect is best .The dynamic stress generated by rotation is not sensitive to the external force .The change of peak stress is small with the change of external exciting force at a certain shroud interval .These con-clusions have important guiding significance in design of turbine blades .