Vibration characteristics of complex aero-engine rotors considering support constraints
-
摘要:
针对航空发动机转子复杂的结构特征及支承动力学设计问题,基于有限元 (FE)、分段线性拟合和自由度 (DOF)降维法,采用主子单元对复杂转子进行合理地等效,构建了航空发动机等复杂转子-支承系统的动力学模型,并对模型的有效性进行了试验验证。从转子固有特性、应变能分布、支承传递力和振动响应等方面对支承刚度进行了设计,并开展了弹性支承并联挤压油膜阻尼器 (SFD)非线性减振效率分析。结果表明:动力学模型能较好地反映复杂转子的动力学特性,支承刚度合适取值范围为1.5×104~2.8×104 N/mm,弹性支承并联SFD设计减振和降支承力效果显著,满足临界转速设计准则、应变能约束条件和变形要求,该研究为航空发动机支承刚度和SFD并联设计提供了定量的参考依据,具有重要的工程应用价值。
Abstract:In view of the complex structural features and support with dynamic design problems for aero-engine rotors, based on finite element (FE), piecewise linear fitting and degree of freedom (DOF) reduction, the dynamic model of complex rotor-support system of the aero-engine was built by using the main and sub-units to reasonably equivalize the complex rotor, and the validity of the modeling was verified through experiments. The supporting stiffness was designed from the aspects of rotor natural characteristics, strain energy distribution, supporting force and vibration response, and the nonlinear vibration reduction efficiency analysis of elastic support parallel squeeze film damper (SFD) was carried out. The results showed that the dynamic model can reflect the dynamic characteristics of complex rotors well. The appropriate range of support stiffness was 1.5×104−2.8×104 N/mm, and the elastic support parallel SFD design had a significant effect on reducing vibration and supporting force, which met the critical speed design, strain energy constraint and deformation requirement. It provides a quantitative reference basis for aero-engine supporting stiffness and SFD parallel design, which has important engineering application value.
-
表 1 前4阶固有频率
Table 1. The first four-order natural frequencies
阶次 固有频率/Hz 相对误差/% 计算值 实测值 1 6.88 6.70 2.74 2 19.40 19.10 1.57 3 97.32 96.13 1.23 4 139.15 134.88 3.16 表 2 临界转速阈值与支承刚度的关系
Table 2. Relationship between the critical speed threshold and the support stiffness
转速/(r/min) 刚度/(N/mm) 增长率/% 1#支承 2#支承 29166 45538 61502 35.06 35000 99742 118309 18.62 50000 2474491 表 3 临界转速随支承刚度变化率
Table 3. Change rate of critical speeds with stiffness
阶次 临界转速/(r/min) 增长率/% 刚度缩小5倍 刚度增大5倍 1 5119.40 18967.56 270.50 2 10744.53 43539.55 305.23 3 69793.74 86253.47 23.58 表 4 支承刚度对位移振幅的影响
Table 4. Effect of support stiffness on displacement vibration amplitude
转速/(r/min) 位移振幅x/μm 增长率/% K1 K2 1阶转速点 26.27 43.24 64.59 2阶转速点 3.24 8.64 166.64 35000 0.14 0.38 179.87 40000 0.29 0.38 30.03 45000 0.53 0.52 −1.75 50000 0.90 0.77 −14.48 表 5 支承刚度对支承力的影响
Table 5. Effect of support stiffness on the support force
转速/(r/min) 支承力/N 增长率/% K1 K2 1阶转速点 394.07 1513.30 284.02 2阶转速点 48.62 302.42 521.99 35000 2.03 13.26 552.40 40000 4.42 13.40 203.01 45000 8.00 18.31 128.88 50000 13.52 26.92 99.16 表 6 有SFD时支承刚度对振幅的影响
Table 6. Effect of support stiffness on displacement vibration amplitude with SFD
转速/(r/min) 位移振幅x/μm 增长率/% K1 K2 1阶转速点 2.00 3.19 59.2 35000 0.13 0.311 140.29 40000 0.29 0.36 26.71 45000 0.52 0.51 −1.84 50000 0.86 0.75 −13.28 表 7 有SFD时支承刚度对支承力的影响
Table 7. Effect of support stiffness on the support force with SFD
转速/(r/min) 支承力/N 增长率/% K1 K2 1阶转速点 33.07 116.67 252.85 35000 3.59 13.11 264.98 40000 8.79 16.04 82.42 45000 17.50 23.63 35.02 50000 31.68 36.36 14.76 表 8 SFD减振和降支承力效果
Table 8. Effect of SFD reducing vibration and support force
参数 同相不平衡 异相不平衡 1#支承 2#支承 1#支承 2#支承 无
SFD有
SFD减振率/
%无
SFD有
SFD减振率/
%无
SFD有
SFD减振率/
%无
SFD有
SFD减振率/
%振动
峰值/μm1阶 31.3 2.3 92.5 56.5 4.7 91.7 7.6 0.8 89.1 13.8 1.5 89.3 2阶 4.6 3.2 75.6 3.5 95.4 51.6 2.4 95.4 支承力
峰值/N1阶 624.9 50.5 91.9 1129.7 94.1 91.7 151.9 2.5 98.4 275.5 29.6 89.3 2阶 92.0 64.6 1511.7 94.5 93.8 1032.5 49.3 95.2 -
[1] WANG Longkai,WANG Ailun,JIN Miao,et al. Vibration prediction and failure analysis based on refined modeling of turbocharging rotor system with variable cross sections[J]. European Physical Journal Plus,2021,137(1): 1-24. [2] 洪杰,宋制宏,王东,等. 高速转子系统支承结构及力学特性设计方法[J]. 航空动力学报,2019,34(5): 961-970. doi: 10.13224/j.cnki.jasp.2019.05.001HONG Jie,SONG Zhihong,WANG Dong,et al. Design method for bearing-support structure and mechanical properties of high-speed rotor system[J]. Journal of Aerospace Power,2019,34(5): 961-970. (in Chinese) doi: 10.13224/j.cnki.jasp.2019.05.001 [3] 雷冰龙,李超,何康,等. 共用支承-转子系统耦合振动特性分析及试验[J]. 航空动力学报,2020,35(11): 2293-2305.LEI Binglong,LI Chao,HE Kang,et al. Coupling vibration characteristics analysis and experiment of shared support-rotors system[J]. Journal of Aerospace Power,2020,35(11): 2293-2305. (in Chinese) [4] 陈果. 航空发动机整机振动耦合动力学模型及其验证[J]. 航空动力学报,2012,27(2): 241-254.CHEN Guo. A coupling dynamic model for whole aero-engine vibration and its verification[J]. Journal of Aerospace Power,2012,27(2): 241-254. (in Chinese) [5] 罗贵火,周海仑,王飞,等. 含滚动轴承的同向和反向旋转双转子系统动力学响应[J]. 航空动力学报,2012,27(8): 1887-1894.LUO Guihuo,ZHOU Hailun,WANG Fei,et al. Dynamics response of co-rotating and counter-rotating dual-rotor system supported on ball bearing[J]. Journal of Aerospace Power,2012,27(8): 1887-1894. (in Chinese) [6] WANG Longkai,WANG Ailun,YIN Yijun,et al. Effects of unbalance orientation on the dynamic characteristics of a double overhung rotor system for high-speed turbochargers[J]. Nonlinear Dynamics,2022,107(1): 665-681. doi: 10.1007/s11071-021-07068-w [7] 张大义, 刘烨辉, 梁智超, 等. 航空发动机双转子系统临界转速求解方法[J]. 推进技术, 2015, 36(2): 292-298.ZHANG Dayi, LIU Yehui, LIANG Zhichao, et al. Prediction for critical speed of double spools system in aero engines[J]. Journal of Propulsion Technology, 2015, 36(2): 292-298. (in Chinese) [8] 王龙凯,王艾伦,金淼,等. 含内阻的拉杆组合转子双稳态振动特性[J]. 中国机械工程,2021,32(5): 512-522,564. doi: 10.3969/j.issn.1004-132X.2021.05.002WANG Longkai,WANG Ailun,JIN Miao,et al. Bistable vibration characteristics of rod fastening rotor with internal damping[J]. China Mechanical Engineering,2021,32(5): 512-522,564. (in Chinese) doi: 10.3969/j.issn.1004-132X.2021.05.002 [9] WANG Longkai,WANG Ailun,JIN Miao,et al. Nonlinear effects of induced unbalance in the rod fastening rotor-bearing system considering nonlinear contact[J]. Archive of Applied Mechanics,2020,90(5): 917-943. doi: 10.1007/s00419-019-01645-7 [10] WANG Longkai,WANG Ailun,JIN Miao,et al. Nonlinear dynamic response and stability of a rod fastening rotor with internal damping effect[J]. Archive of Applied Mechanics,2021,91(9): 3851-3867. doi: 10.1007/s00419-021-01981-7 [11] SINHA S K. Rotor dynamic analysis of asymmetric turbofan rotor due to fan blade-loss event with contact-impact rub loads[J]. Journal of Sound and Vibration,2013,332(9): 2253-2283. doi: 10.1016/j.jsv.2012.11.033 [12] 廖子豪,宾光富,李超,等. 基于临界转速与振型相似的涡轴发动机模拟转子实验台设计方法[J]. 机械设计,2021,38(6): 45-50.LIAO Zihao,BIN Guangfu,LI Chao,et al. Design method of the simulated-rotor test rig for the turboshaft engine based on the critical speed and the similarity of vibration mode[J]. Journal of Machine Design,2021,38(6): 45-50. (in Chinese) [13] 邓旺群,吴施志,刘文魁,等. 带柔性静子结构高速转子支承刚度修正方法[J]. 振动与冲击,2020,39(7): 29-35, 66. doi: 10.13465/j.cnki.jvs.2020.07.005DENG Wangqun,WU Shizhi,LIU Wenkui,et al. Support stiffness modification method for a high-speed rotor with flexible stator[J]. Journal of Vibration and Shock,2020,39(7): 29-35, 66. (in Chinese) doi: 10.13465/j.cnki.jvs.2020.07.005 [14] 唐虎标,邓旺群,刘文魁,等. 航空发动机燃气发生器转子不平衡响应分析及试验研究[J]. 长沙航空职业技术学院学报,2021,21(2): 1-5. doi: 10.13829/j.cnki.issn.1671-9654.2021.02.001TANG Hubiao,DENG Wangqun,LIU Wenkui,et al. Research on unbalance response and experiment of gas generator rotor of an aero engine[J]. Journal of Changsha Aeronautical Vocational and Technical College,2021,21(2): 1-5. (in Chinese) doi: 10.13829/j.cnki.issn.1671-9654.2021.02.001 [15] 马艳红,何天元,张大义,等. 支承刚度非线性转子系统的不平衡响应[J]. 航空动力学报,2014,29(7): 1527-1534. doi: 10.13224/j.cnki.jasp.2014.07.003MA Yanhong,HE Tianyuan,ZHANG Dayi,et al. Imbalance response of rotor system with nonlinear bearing stiffness[J]. Journal of Aerospace Power,2014,29(7): 1527-1534. (in Chinese) doi: 10.13224/j.cnki.jasp.2014.07.003 [16] 《航空发动机设计手册》总编委会. 航空发动机设计手册: 第19册 转子动力学及整机振动[M]. 北京: 航空工业出版社, 2000: 210-220. [17] 刘展翅,廖明夫,丛佩红,等. 航空发动机转子挤压油膜阻尼器设计方法[J]. 航空动力学报,2015,30(11): 2762-2770. doi: 10.13224/j.cnki.jasp.2015.11.026LIU Zhanchi,LIAO Mingfu,CONG Peihong,et al. Design method of squeeze film damper for aero-engine rotors[J]. Journal of Aerospace Power,2015,30(11): 2762-2770. (in Chinese) doi: 10.13224/j.cnki.jasp.2015.11.026 [18] CHEN W J,RAJAN M,RAJAN S D,et al. The optimal design of squeeze film dampers for flexible rotor systems[J]. Journal of Mechanisms Transmissions and Automation in Design,1988,110(2): 166-174. doi: 10.1115/1.3258922 [19] NELSON H D. A finite rotating shaft element using Timoshenko beam theory[J]. Journal of Mechanical Design,1980,102(4): 793-803. doi: 10.1115/1.3254824 [20] CHEN W J, GUNTER E J. Introduction to dynamics of rotor-bearing systems[M]. Victoria, Canada: Trafford Publishing, 2010. [21] 王海,王艾伦,马伍,等. 组合转子变态模型动力学相似设计方法研究[J]. 机械设计,2020,37(9): 7-11.WANG Hai,WANG Ailun,MA Wu,et al. Research on the dynamic similarity design for the abnormal model of combined rotors[J]. Journal of Machine Design,2020,37(9): 7-11. (in Chinese) [22] 宋明波,夏商周,赵海凤,等. 典型燃气发生器转子平衡状态与振动特性分析[J]. 航空发动机,2021,47(2): 79-83.SONG Mingbo,XIA Shangzhou,ZHAO Haifeng,et al. Analysis on balancing state and vibration characteristics of a typical gas generator rotor[J]. Aeroengine,2021,47(2): 79-83. (in Chinese) [23] 王正. 转动机械的转子动力学设计[M]. 北京: 清华大学出版社, 2015.