不平衡激励作用下周向加肋机匣振动能量传递机理

为了研究周向加肋机匣对整机振动的抑制机理,采用有限元法建立了加肋机匣-支承-转子耦合结构,结合振动功率流法分析了在转子不平衡激励作用下周向加肋机匣中的振动能量传递机理。 结果表明:机匣周向加肋筋诱导出的能量涡流场能够分流和耗散掉部分由转子传递至机匣的振动能量；机匣周向加肋筋改变了振动能量的传递路径,减小了机匣与支板连接处振动能量的回流现象；振动能量传递到机匣周向加肋筋后发生传递波波形的转换,携带大部分振动能量的弯曲波转换为纵波并沿加肋筋周向传递,阻断振动能量沿轴向传递至整机其他部位。 研究结果可为航空发动机结构设计以及整机减振提供参考。 

Vibration energy transmitting mechanism of ring-stiffened casing excited by rotor unbalance

To analyze how the ring-stiffened casing attenuate the overall vibration of aero-engine, a ring-stiffened casing-supporting-spindle coupling model was established by the finite element method, and the vibration power flow method was applied to analyze the vibration energy transmitting mechanism of ring-stiffened casing under the excitation of rotors unbalance. According to above analysis, following conclusion can be summarized: ①Energy vortexes field derived by the ring-stiffened rib can partly detour and dissipate the vibration energy transmitted through spindle to casing; ②The ring-stiffened rib changed the vibration energy transmitting path and attenuate vibration energy backflow; ③The type of energy transmitting wave changed when the vibration energy was transmitted to the ring-stiffened rib, the flexural wave carrying the most of vibration energy was changed to the longitudinal wave, and made the vibration energy transmit along the circumferential direction of the ring-stiffened rib. This prevented the vibration energy from transmitting to other area of casing along the axial direction. The conclusions can provide references for whole aero-engines structure design and overall vibration attenuation.