考虑正压力分配的B-B型涡轮叶片缘板阻尼器系统减振特性研究

Study on vibration reduction characteristics of the B-B type turbine blade under-platform damper system considering the normal load allocation

为提升涡轮叶片缘板阻尼器设计水平,对比B-G(blade to ground)型阻尼器和切向无约束B-B(blade to blade)型阻尼器结构,提出了一种基于刚度设计的B-B型缘板阻尼器结构。在动力学建模中重点分析了相邻叶片缘板和阻尼器之间总的正压力随阻尼器与左、右叶片缘板间相对运动在左、右缘板间的分配,给出了基于阻尼器运动的正压力分配方法;通过数值仿真分析了正压力分配对系统振动响应的影响,并重点讨论了阻尼器刚度、外激励相位差、正压力以及外激励幅值对系统减振特性的影响。仿真结果表明,在左、右叶片缘板与阻尼器完全粘滞和左、右叶片相对阻尼器对称同步振动的工况下可以将正压力按照平均分配处理;相比于切向无约束的B-B型阻尼器和刚性的B-G型阻尼器,所提出的基于刚度设计的缘板阻尼结构具有更优的减振性能。因此,研究结果提升了涡轮叶片缘板阻尼器接触正压力计算的准确性,拓展了阻尼器设计思路,可为同类阻尼器设计提供理论和工程参考。

In order to improve the design level of the under-platform damper of aero-engine turbine blades, a B-B type under-platform damper structure based on stiffness design was proposed by comparing with structures of the B-G(blade to ground) type damper and the tangential unconstrained B-B(blade to blade) type damper.In the dynamic modeling, the allocation of the total normal load between the damper and adjacent platforms was analyzed with relative motions between left and right platforms and the damper, and the allocation method of the normal load based on the motion of the damper was put forward.The influence of normal load allocation on the vibration response of the damped system was analyzed by numerical simulation, and the effects of damper stiffness, external excitation phase difference, total normal load and external excitation amplitude on the vibration reduction characteristics of the system were discussed in detail.The simulation results show that the normal load can be evenly allocated when the contact surfaces between left and right platforms and the damper are completely stick or the motions of adjacent blades relative to the damper are fully symmetric.The B-B type damper based on stiffness design proposed in this paper has better vibration reduction performance comparing with the tangential unconstrained B-B type damper and the rigid B-G type damper.This study improves the computational accuracy of the contact normal load between the turbine blade platform and the damper, expands the design idea of the damper and provides a theoretical and engineering reference for the design of this kind of damper.