航空发动机外部管路的结构与动力学特征参数分析

针对航空发动机外部管路系统的动力学设计需求,采用理论计算与试验测试相结合的方法研究管路系统的关键设计参数及影响规律。研究结果表明:外径、跨度和弯曲角度是影响导管振动特性的主要结构与装配参数,随外径增大,导管基频提高;随跨度增大,基频降低;随弯曲角度增大,基频提高。而弯曲半径、壁厚和安装横向偏移对固有特性的影响很小,可不予考虑。导管充液后,各阶模态频率会略有降低,液体密度越大,影响越大;而流体压力和速度对模态特性影响很小,可不予考虑。

Analysis of Structural and Dynamical Characteristic Parameters of External Pipes for Aeroengine

Aiming at the requirement of dynamical design for external pipes of aeroengine, the key design parameters and the influence law were investigated through theoretical calculation and experimental tests. The results show that the external diameter, spacing length and bending angle are the key structure and assembling parameters, which affect the natural vibration characteristics significantly. The first mode frequency increases when the external diameter and bending angle increase, nevertheless, the first mode frequency decrease when the spacing length increases. The bending radius, wall thickness and assembling lateral shift have a little effect on the natural characteristics, which could be ignored during design.The natural frequency is slightly reduced when the pipes are filled with liquid, and the greater the liquid density, the smaller the mode frequency. However, the pressure and velocity of the liquid affect the natural characteristics barely, which could be ignored.