机动飞行下磁流变阻尼器-转子系统动力学特性

Dynamic characteristics of rotor system with magnetorheological damper during maneuvering flight

航空发动机在机动飞行过程中,工作条件非常恶劣,飞行过程会产生不规则的瞬态振动,易引发故障。采用有限元法建立机动飞行下基于双线性本构方程的磁流变阻尼器-转子系统有限元模型,并利用Newmark-β数值方法进行求解,研究转子系统在机动飞行过程中的动态特性。在此基础上,考虑磁流变阻尼器作用,研究其对冲击载荷下转子系统瞬态及稳态响应的影响。结果表明,机动飞行开始和结束瞬间会产生瞬态冲击,激发转子系统一阶模态响应。在合适的电流作用下,变阻尼器可以有效抑制机动飞行过程中转子系统瞬态及稳态响应。此外,在机动飞行下,由于轴颈离心率较大,易导致磁流变阻尼器产生非线性行为。

In the process of maneuvering flight,the aeroengine will bear very harsh working conditions,leading to irregular transient vibrations that can result in failure.In this paper,the effect of a semi-active magnetorheological damper(MR damper) on the dynamic characteristics of a rotor system under maneuvering flight is investigated.The finite element model of the rotor system with MR damper under maneuvering flight is established using the finite element method.The Newmark-β numerical method is used to solve the dynamic equations,and the dynamic characteristics of the rotor system during maneuvering flight are studied.On this basis,considering the effects of MR damper on the transient,the steady state responses of the rotor system under maneuvering flight are analyzed.The results show that transient impact is caused at the beginning and the end of maneuvering flight,which stimulates the first order modal response of the rotor system.The MR damper with suitable current can effectively suppress the amplitudes of transient and steady-state responses of the rotor system during maneuvering flight.In addition,due to the large eccentricity of the journal in maneuvering flight,the MR damper is prone to produce nonlinearity.