To evaluate the vibration coupling effect of the intershaft bearing on the dual-rotor system, this paper illustrates the expressions and relations of the coupling vibration of the two rotors and proposes the corresponding evaluation indexes or methods, from the perspectives of the mode shape change at the critical speed, the critical speed change, the change of the strain energy distribution between the mode shape and the steady-state unbalanced response, and the change of the bearing force of the intermediate shaft. The typical dual-rotor system of gas turbine engines is analyzed and evaluated. The results show that the mode shapes of single rotors may appear in three forms in the dual-rotor mode shapes:one-to-one corresponding, repeated, or coupled. The corresponding critical speed and strain energy distribution will also change accordingly. The peak value of the intermediate shaft bearing force appears at the critical speed position, while the speed position with the largest change of strain energy distribution is not consistent with the critical speed position of the system, and is affected by the unbalanced excitation position. The curve of the strain energy ratio of each element with the change of rotating speed can analyze the change of strain energy distribution of the system under the specific unbalanced excitation. The method can be used as a reference for the design and fault diagnosis of the dual-rotor intershaft bearing system.
[1] HIBNER D H. Dynamic response of viscous-damped multi-shaft jet engines[J]. Journal of Aircraft, 1975, 12(4):305-312.
[2] GUPTA K, GUPTA K D, ATHRE K. Unbalance response of a dual rotor system:Theory and experiment[J]. Journal of Vibration and Acoustics, Transactions of the ASME, 1993, 115(4):427-435.
[3] GUPTA K, KUMAR R, TIWARI M, et al. Effect of rotary inertia and gyroscopic moments on dynamics of two spool aero engine rotor[C]//ASME 1993 International Gas Turbine and Aeroengine Congress and Exposition. New York:ASME, 1993:1-14.
[4] GUSKOV M, SINOU J J, THOUVEREZ F, et al. Experimental and numerical investigations of a dual-shaft test rig with intershaft bearing[J]. International Journal of Rotating Machinery, 2007:1-12.
[5] 罗贵火. 反向旋转双转子系统振动特性分析与试验研究[D]. 南京:南京航空航天大学, 1999. LUO G H. Analysis and Experimental research on vibration characteristics of reverse rotating double rotor system[D]. Nanjing:Nanjing University of Aeronautics and Astronautics, 1999(in Chinese).
[6] 胡绚. 反向旋转双转子系统动力学特性研究[D]. 南京:南京航空航天大学, 2007. HU X. Research on the dynamical characteristics of counter-rotating dual-rotor system[D]. Nanjing:Nanjing University of Aeronautics and Astronautics, 2007(in Chinese).
[7] 胡绚, 罗贵火, 高德平, 等. 反向旋转双转子稳态响应计算分析与试验[J]. 航空动力学报, 2007, 22(7):1044-1049. HU X, LUO G H, GAO D P, et al. Numerical analysis and experiment of counter-rotating dual-rotor's steady-state response[J]. Journal of Aerospace Power, 2007, 22(7):1044-1049(in Chinese).
[8] 张力, 洪杰, 马艳红. 航空发动机转子系统建模方法和振动特性分析[J]. 北京航空航天大学学报, 2013, 39(2):148-153,163. ZHANG L, HONG J, MA Y H. Modeling method and vibration characteristics of aero-engine rotor system[J]. Journal of Beijing University of Aeronautics and Astronautics, 2013, 39(2):148-153,163(in Chinese).
[9] 洪杰, 王华, 肖大为, 等. 转子支承动刚度对转子动力特性的影响分析[J]. 航空发动机, 2008, 34(1):23-27. HONG J, WANG H, XIAO D W, et al. Effects of dynamic stiffness of rotor bearing on rotor dynamic characteristics[J]. Aeroengin, 2008, 34(1):23-27(in Chinese).
[10] 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 D Y, LIU Y H, LIANG Z C, et al. Method for solving critical speed of aeroengine dual-rotor system[J]. Propulsion Technology, 2015, 36(2):292-298(in Chinese).
[11] 章健, 张大义, 王永锋, 等. 共用支承-转子结构系统振动耦合特性分析[J]. 北京航空航天大学学报, 2019, 45(9):1902-1910. ZHANG J, ZHANG D Y, WANG Y F, et al. Coupling vibration characteristics analysis of shared support-rotors system[J]. Journal of Beijing University of Aeronautics and Astronautics, 2019, 45(9):1902-1910(in Chinese).
[12] 左彦飞. 航空发动机整机系统结构振动分析[D]. 北京:北京航空航天大学, 2016. ZUO Y F. Structural dynamic analysis of the whole aero-engine system[D]. Beijing:Beihang University, 2016(in Chinese).
[13] 李昊. 耦合双转子-组合支承系统动力学特性研究[D]. 大连:大连海事大学, 2016. LI H. Study on dynamics characteristics of coupled double rotor and composite support system[D]. Dalian:Dalian Maritime University, 2016(in Chinese).
[14] 王杰, 左彦飞, 江志农, 等. 支承非对称对双转子系统动力特性的影响规律[J]. 振动与冲击(2019-07-12)[2020-04-06]. WANG J, ZUO Y F, JIANG Z N, et al. Effect of asymmetrical support on dynamic characteristics of dual-rotor system[J]. Journal of Vibration and Shock(2019-07-12)[2020-04-06] (in Chinese).
[15] 邓四二, 付金辉, 王燕霜, 等. 航空发动机滚动轴承-双转子系统动态特性分析[J]. 航空动力学报, 2013, 28(1):195-204. DENG S E, FU J H, WANG Y S, et al. Analysis on dynamic characteristics of aero-engine rolling bearing/dual-rotor system[J]. Journal of Aerospace Power, 2013, 28(1):195-204(in Chinese).
[16] 陈果. 双转子航空发动机整机振动建模与分析[J]. 振动工程学报, 2011, 24(6):619-632. CHEN G. Vibration modeling and analysis for dual-rotor aero-engine, 2011, 24(6):619-632(in Chinese).
[17] 廖明夫, 刘永泉, 王四季. 中介轴承对双转子振动的影响[J]. 机械科学与技术, 2013, 32(5):641-646. LIAO M F, LIU Y Q, WANG S J. The vibration features of a twin spool rotor system with an inter-bearing[J]. Mechanical Science and Technology for Aerospace engineering, 2013, 32(5):641-646(in Chinese).
[18] 高朋, 侯磊, 陈予恕. 双转子-中介轴承系统非线性振动特性[J]. 振动与冲击, 2019, 38(15):1-10. GAO P, HOU L, CHEN Y S. Nonlinear vibration characteristics of a dual-rotor system with inter-shaft bearing[J]. Journal of Vibration and Shock, 2019, 38(15):1-10(in Chinese).
[19] 洪杰, 于欢, 肖森, 等. 高速柔性转子系统非线性振动响应特征分析[J]. 北京航空航天大学学报, 2018, 44(4):653-661. HONG J, YU H, XIAO S, et al. Nonlinear vibration response characteristics of high-speed flexible rotor system[J]. Journal of Beijing University of Aeronautics and Astronautics, 2018, 44(4):653-661(in Chinese).
[20] 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. MA Y H, HE T Y, ZHANG D Y, et al. Imbalance response of rotor system with nonlinear bearing stiffness[J]. Journal of Aerospace Power, 2014, 29(7):1527-1534(in Chinese).
[21] WANGER M B, YOUNAN A, ALLAIRE P, et al. Modal reduction methods for rotor dynamic analysis[J]. International Journal of Rotating Machinery, 2010:1-17.
CJA