典型燃气发生器转子平衡状态与振动特性分析

针对某型涡轴发动机整机试验中出现的振动过大现象,通过建立考虑低速动平衡的刚性转子系统动力学方程,求解低速动平衡后刚性转子的动力学响应,对涡轴发动机典型燃气发生器转子平衡状态与振动特性进行分析。介绍了该型发动机整机试验中出现的振动过大现象及后续的排查措施,分析了该类转子振动模态特性与激振载荷的关系,建立了该类转子在不平衡状态下的动力学分析模型,对2种初始不平衡状态的转子振动响应进行了仿真计算。结果表明:对于该类涡轴发动机典型燃气发生器转子,当离心叶轮处存在较大初始不平衡时,转子的低速动平衡虽能较好地控制其前2阶振动,但会加剧其在大转速时的振动,特别是转子第3阶弯曲型临界转速裕度不大时,应当特别重视。

Analysis on Balancing State and Vibration Characteristics of a Typical Gas Generator Rotor

For the vibration problem of one turboshaft engine,the relationship between the rotor balancing state and the vibration char?acteristics was analyzed by establishing the dynamic equation of rigid rotor after low speed dynamic balancing,and solving the dynamic re?sponse.The vibration problem of one turboshaft engine and the follow-up solutions were introduced.The relationship between the rotor mode and the exciting force was analyzed.The dynamic model of the rotor was established,and the dynamic response of 2 rotor balancing state was calculated.The results show that for this typical rotor of turboshaft engine,if the initial unbalance at about centrifugal impeller is major,even if the vibration of the rotor at the first and second critical speed is suppressed well by low-speed balance,the vibration of the rotor at high speed region will be aggravated,especially the margin for the third critical speed is not enough.