考虑弹性环变形的挤压油膜阻尼器-转子系统动力响应仿真方法

Simulation method for dynamic responses of squeeze film damper-rotor system considering elastic ring deformation

为了研究弹性环式挤压油膜阻尼器(ERSFD)对转子-支承系统动力特性的影响,基于阻尼器的流固耦合交互作用,提出了考虑弹性环变形的转子系统动力学响应仿真方法。针对流固耦合特性仿真,固体域采用有限元法计算弹性环变形,流体域采用有限差分法计算油膜压力分布。将阻尼器的动力学系数引入转子系统,采用扫频法求解系统运动方程,最终得到转子系统的稳态动力响应。研究结构参数对ERSFD阻尼系数的影响发现,油膜阻尼与偏心率、轴向长度正相关,而与凸台高度、凸台个数负相关;凸台宽度在4~12 mm内存在最优值,使得油膜阻尼最大。基于参数影响规律改进阻尼器结构,并应用到转子系统后开展仿真分析。结果表明:ERSFD能够提供较大的油膜阻尼,通过降低支承外传力使得盘处的振幅减小。改进后的ERSFD阻尼更大,盘处一阶减振幅度从28%显著提升至41%。

To investigate the influence of elastic ring squeezed film damper(ERSFD)on the dynamic char⁃acteristics of a rotor-support system,a simulation method for the dynamic responses of the rotor system consider⁃ing elastic ring’s deformation is proposed,based on the fluid-structure coupling interaction of the damper.For simulating fluid-structure coupling features,the deformation of the elastic ring is calculated by finite element method in solid domain,and the pressure distribution of oil-film is calculated by finite difference method in fluid domain.After introducing the dynamic coefficients of ERSFD into the rotor system,the systematic equations of motion are solved by frequency sweeping method,ultimately obtaining the steady-state responses of the rotor sys⁃tem.The effects of structural parameters on ERSFD’s damping coefficient are investigated,the results show that the oil-film damping is positively correlated with eccentricity and axial length,while negatively correlated with the height and number of bosses.There exists an optimal value for the boss width in the range of 4~12 mm,which maximizes the oil-film damping.Based on the influence law of parameters,the improved damper structure is ap⁃plied to the rotor system for simulation analysis.The results indicate that ERSFD can provide relatively large oilfilm damping,reducing the vibration amplitudes at disks due to the lower transmitted force from the supports.The improved ERSFD has larger damping than the initial one,and the reduction in the first-order resonance ampli⁃tude at the disk is significantly increased from 28%to 41%.