航空学报 > 2024, Vol. 45 Issue (3): 229250-229250   doi: 10.7527/S1000-6893.2023.29250

融合柔性基础传递函数的转子系统建模方法及验证

李帅1, 李启行1,2(), 谌璨1, 方志法1, 王维民1,2   

  1. 1.北京化工大学 高端机械装备健康监测与自愈化北京市重点实验室 北京  100029
    2.北京化工大学 高端压缩机及系统技术全国重点实验室 北京  100029
  • 收稿日期:2023-06-30 修回日期:2023-07-23 接受日期:2023-07-30 出版日期:2024-02-15 发布日期:2023-08-24
  • 通讯作者: 李启行 E-mail:liqihang2012@foxmail.com
  • 基金资助:
    国家自然科学基金(12272035);中央高校基本科研业务费专项资金(JD2302)

Modeling method and verification for rotor systems integrated with transfer functions of flexible foundation

Shuai LI1, Qihang LI1,2(), Can CHEN1, Zhifa FANG1, Weimin WANG1,2   

  1. 1.Beijing Key Laboratory of Health Monitoring and Self-recovery for High-end Mechanical Equipment,Beijing University of Chemical Technology,Beijing  100029,China
    2.State Key Laboratory of High-end Compressor and System Technology,Beijing University of Chemical Technology,Beijing  100029,China
  • Received:2023-06-30 Revised:2023-07-23 Accepted:2023-07-30 Online:2024-02-15 Published:2023-08-24
  • Contact: Qihang LI E-mail:liqihang2012@foxmail.com
  • Supported by:
    National Natural Science Foundation of China(12272035);The Fundamental Research Funds for the Central Universities(JD2302)

摘要:

航空发动机、火箭涡轮泵等现代高端涡轮机械对性能有着极致的需求,其轻柔化的支承结构导致转子与柔性基础振动耦合特性明显,必须将其柔性支承结构纳入整体动力学分析之中。然而,柔性基础的高精度建模过程需要耗费大量时间,同时简化的基础模型也难以表达其真实的动力学特性。为此,提出了融合柔性基础传递函数的转子系统动力学建模仿真方法:将实测得到的柔性基础传递函数通过状态子空间法拟合获得低维时域和频域表征的数学模型,通过支承力模型将柔性基础模型耦合到转子有限元模型之中,最终形成基于实物传递函数的混合转子动力学模型。同时,提出了柔性基础从稳态到瞬态的模型转换策略,并采用线性-非线性节点(显-隐)分离的快速瞬态数值积分方法进行求解。基于所提模型和计算方法,开展了柔性基础-转子系统的稳态、瞬态动力学数值仿真,以及稳定转速扫频激励和降速不平衡激励的振动测试试验,结果表明:实测的柔性基础振动特性,能够有效地体现在整机动力学分析之中,且考虑柔性基础特性的转子动力学模型所预测的瞬态动力学响应与试验结果更为吻合。所提方法为含复杂柔性基础的转子系统提供了行之有效的整机建模及瞬态仿真方法。

关键词: 转子动力学, 柔性基础, 瞬态仿真, 传递函数, 快速瞬态数值积分

Abstract:

Modern high-end turbomachines, such as aviation engines and rocket turbo pumps, have extremely high demands for performance. The flexible support structure of these machines results in significant coupling of vibration characteristics between the rotor and flexible foundation, making it necessary to include the flexible support structure in the overall dynamic analysis. However, the modeling process of high accuracy flexible support structures needs to take considerable time, and the simplified support model cannot represent the dynamic characteristics of real support structures. Therefore, a simulation method for rotor system dynamic modeling integrated with flexible foundation transfer functions is proposed. The measured transfer functions of the flexible foundation are fitted by the state subspace method to obtain a low-dimensional mathematical model with time-domain and frequency-domain representation. The flexible foundation model is coupled to the rotor finite element model through the support force model to form a hybrid rotor dynamic model based on physical transfer functions. At the same time, a model transformation strategy for flexible foundations from steady-state to transient is proposed, and a fast transient numerical integration method with linear-nonlinear (explicit-implicit) node separation is used to solve the problem. Based on the proposed model and computational method, numerical simulations of steady-state and transient dynamics of the flexible foundation-rotor system are conducted, as well as vibration testing experiments with the sweep frequency excitation at a stable speed and unbalance excitation during shut-down. The results show that the measured vibration characteristics of the flexible foundation can be effectively coupled in the overall dynamic analysis, and the transient dynamic response predicted by the rotor dynamic model, considering the flexible foundation characteristics, is more consistent with the experimental results. The proposed method provides an effective approach for modeling and simulating the overall system with complex flexible foundations.

Key words: rotordynamics, flexible foundation, transient simulation, transfer function, fast transient numerical integration

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