小展弦比带掠风扇转子叶片的耦合颤振

从结构力学出发,对某发动机整体叶盘进行了盘片耦合振动特性分析,通过分析小展弦比带掠风扇转子叶片的共振转速、耦合颤振和失速颤振,发现了该小展弦比带掠风扇转子叶片存在2阶与3阶动频与静频振型发生变化的特殊现象,揭示了该小展弦比带掠风扇转子叶片为另一种耦合颤振的问题.通过对该小展弦比带掠风扇转子叶片的结构调整,找出了叶片前掠是该叶片发生此类特殊现象的重要影响因素,适当压缩该叶片的前掠后,从设计上避免了发生颤振的可能,提出叶片各阶频率的分离度需满足10％的设计要求. 

Coupling flutter of swept fan rotor blade with small aspect ratio

Based on structural mechanics, blade coupling flutter characteristics of an engine blisk were analyzed.Analyses of resonance rotating speed, coupling flutter and stall flutter were accomplished by swept fan rotor blade with small aspect ratio. The unusual phenomena showing that the change of dynamic and static frequencies of second-order and third-order on the swept fan blade with small aspect ratio were found, and recognized as another problem relating to coupling flutter. By structure adjustment of swept fan rotor blade with small aspect ratio, it was found that swept-forward blade was an important factor to this unusual phenomenon. Reducing the swept degree of the blade appropriately can avoid the possibility of flutter by design.It is suggested the separation of order frequency degree for the blade should satisfy the design requirement of 10%.