带中介轴承双转子系统“可容模态”优化设计及实验

Optimization Design and Experiment of Workable Mode for Dual-Rotor System with Inter-Shaft Bearing

关键词:  航空发动机  双转子系统  可容模态  优化设计  实验验证

Key words:  Aero-engine  Dual-rotor system  Workable mode  Optimization design  Experimental verification

摘要:

为解决航空发动机双转子系统无法避开临界转速的问题，提高双转子系统容忍振动的能力，根据带中介轴承双转子系统的“可容模态”优化设计方法，以某型带中介轴承双转子发动机相似模型为初始模型进行优化设计，并以此搭建一套双转子实验器系统。通过模态测试、响应测试、连续变转速以及长时间“共振”实验，先后验证了带中介轴承双转子系统的“可容模态”优化设计方法的准确性、有效性、稳定性和可靠性。研究发现，双转子实验器测试结果与计算结果临界转速误差最高3.06%、模态振型误差最高9.6%；工作范围内任意转速下，即使频繁穿越临界转速，振动幅值均不超过50μm；在6阶临界转速处各完成了不少于3790s的“共振”实验，所容忍的不平衡量最大为设计不平衡量的5.2倍，振幅平稳，且可容度评价函数值越高，容忍共振能力越强。实验结果充分验证了带中介轴承双转子系统的“可容模态”优化设计方法是可行的。

Abstract:

In order to solve the problem that the dual-rotor system of aero-engine cannot avoid the critical speed， and improve the vibration tolerance of the dual-rotor system， according to the optimization design method for the workable mode of dual-rotor system with inter-shaft bearing， the similar model of a dual-rotor engine with inter-shaft bearing is used as the initial model for optimization design. Based on the optimization results， a dual-rotor test rig system was built. The accuracy， effectiveness，stability and reliability of the optimization design method for the workable mode of dual-rotor system with inter-shaft bearing were verified by modal test， response test， continuous variable speed experiment and long time resonance experiment. According to research findings， the maximum error of the critical speed between the experimental results and the calculation results of the dual-rotor test rig system is 3.06%， and the maximum error of the modal shape is 9.6%. The vibration amplitude is less than 50 μm at any speed even though the critical speed is frequently passed in the working range. The resonance experiments at the sixth critical speed are completed at no less than 3790s. The maximum tolerated amount of unbalance mass is 5.2 times the designed amount. The amplitude is stable， and the higher the tolerability evaluation function is， the higher the tolerance to resonance is. The results indicate that the established optimization design method of workable mode for aero-engine dual-rotor system with inter-shaft bearing is effective.