Effect of asymmetrical supports on the dynamic characteristics of a dual-rotor system
WANG Jie1，ZUO Yanfei1，JIANG Zhinong2，FENG Kun2，HU Minghui3，ZHANG Wenhai3
1.Key Lab of Engine Health Monitoring-Control and Networking of Ministry of Education, Beijing University of Chemical Technology, Beijing 100029, China;
2.Beijing Key Laboratory of High-end Mechanical Equipment Health Monitoring and Self-Recovery, Beijing University of Chemical Technology, Beijing 100029, China;
3.Aero Engine Vibration Health Monitoring-Control Joint Lab, AVIC Shenyang Engine Design Institute-Beijing University of Chemical Technology, Beijing 100029，China
Abstract：The asymmetry of support stiffness widely exists in the rotor support system. However, the complex influence of asymmetric support on the dynamic characteristics of the dual-rotor system in engineering is not clear. For this reason, the dual-rotor support system with typical engine rotating in the same direction is taken as the research object. According to the characteristics of the thin-walled flexible casing support of the engine, the index of support asymmetry coefficient is proposed, and the effects of the existence of support asymmetry and its variation on the critical speed, steady-state unbalance response, whirling direction and whirling trajectory of the dual-rotor support system are studied. It is found that the asymmetry of the support will lead to the increase of the forward critical speed and the decrease of the backward critical speed corresponding to the relevant modes. The response peak of some pivots appears near the critical speed of whirling and it is accompanied by the change of vibration phase in the whirling plane. The whirling of the rotor is more complex. The forward and backward whirling occur simultaneously on the same rotor, and the whirling trajectory of the specific node of the rotor will change more complex with the rotational speed. Further study shows that the increase of the asymmetric coefficient will result in an overall increase in the speed and position regions where the backward whirling occurs, but the area of the backward whirling may also decrease in the specific speed or position. The obtained influence can provide reference for the dynamic design of engine dual-rotor system under complex support conditions and the explanation of the special vibration phenomena.
王杰1，左彦飞1，江志农2，冯坤2，胡明辉3，张文海3. 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, 2020, 39(18): 27-33.
WANG Jie1，ZUO Yanfei1，JIANG Zhinong2，FENG Kun2，HU Minghui3，ZHANG Wenhai3. Effect of asymmetrical supports on the dynamic characteristics of a dual-rotor system. JOURNAL OF VIBRATION AND SHOCK, 2020, 39(18): 27-33.
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