失谐设计在叶片自激振动减振中的应用

Application of Mistuned Design in Vibration Reduction of Blade Self-excited Vibration

为了降低叶片发生颤振、非同步振动等自激振动的风险,以某压气机转子叶片为对象开展失谐设计减振技术应用研究。通过求解考虑非定常气动力的运动方程,获得不同频率分布下的特征值,用特征值虚部的最小值评估气动弹性稳定性。在此基础上,系统地分析了隔离带数量、位置和隔离带内叶片频率分布等参数对自激振动的影响,并开展整机动应力测量,验证叶片失谐设计的减振能力。结果表明:隔离带失谐设计能有效降低由自激振动引起的振动应力,具有不需对发动机结构进行修改、发动机性能不降低、操作便捷、应用成本低的优点。

In order to reduce the risk of blade self-excited vibration,such as flutter and non-synchronous vibration,the technology study on the vibration reduction of mistuned design was carried out for a compressor rotor blade.By solving the motion equations considering unsteady aerodynamic forces,the eigenvalues of different frequency distributions were obtained and the aeroelastic stability was evaluated by the minimum value of the imaginary part of the eigenvalues.On the basis of this,the influence of the number,position and frequency distribution of the blades was systematically analyzed in the isolation zone on the self-excited vibration,and the dynamic stress test of the engine was carried out to verify the vibration reduction of the blade mistuned design.The results show that the mistuned design of the isolation zone can effectively reduce the vibration stress caused by the self-excited vibration,and has the advantages of no modification to the engine structure,no decrease of engine performance,easy operation and low cost.