摘要
利用叶冠之间的干摩擦力产生的阻尼,是一种抑制叶片振动、降低叶片动应力的有效手段。本文以某型汽轮机中压第一级动叶片为研究对象,建立了带平行冠叶片的Sgn干摩擦阻尼模型,将叶冠接触面之间的干摩擦力转换为等效刚度和等效阻尼。计算了其在不同预扭量条件下的动应力,分析了不同预扭量的减振效果。计算结果表明：采用0.4mm的预扭量,叶片的动应力数值较无预扭情况下减小约50%,预扭工艺的减振效果明显。进一步增进预扭量,动应力减小的幅度非常有限（〈5%）,目前采用的预扭量是较为合理的。
Dry friction damper was an effective way to reduce the vibration stress of the shrouded turbine blades.Dry friction forces between the shrouds,which was induced by pre-twisting the turbine blade,was transferred to equivalent stiffness and damping by using a Sgn dry friction damping model.Vibration stress was calculated under different pre-twisting distances.The results show that while the pre-twisting distance is 0.4mm,vibration stress is about 50% lower than that of non pre-twisting.The current pre-twisting technics could reduce the vibration stress and the reasonable pre-twisting distance is 0.4mm.
出处
《热力透平》
2010年第1期51-53,共3页
Thermal Turbine
关键词
涡轮叶片
干摩擦阻尼
有限元
shrouded turbine blades
dry friction
finite element method
