摘要
针对某型航空发动机试车过程中的稳态振动波动问题,开展了时域和频域分析,指出振动波动是由于低压2倍频和高压基频振动拍振所引起.推导了航空发动机拍振引起的振动响应,建立了某型航空发动机双转子动力学模型,并进行了仿真分析.仿真结果表明,当发动机两个激振力频率相近时,会产生拍振引起振动波动,仿真结果与试验结果相吻合.结合发动机结构和其工作特点,分析了发动机形成低压倍频-高压基频耦合拍振的条件,给出了拍振排除方法,并通过试验验证了方法的正确性.工程上可以通过调整高压和低压转子转差关系,将转速比调整到合理范围内即可消除拍振.
Abstract
In order to tackle the steady vibration fluctuation issues in engine tests,the thorough frequency-domain analysis and time-domain analysis are performed.It is found that the vibration fluctuation is induced by the beat vibration between the low-pressure(LP)bi-frequency and high-pressure(HP)fundamental frequency.The vibration response resulted from the beat vibration is calculated.The dual-rotor dynamic model of the aero-engine is established and the numerical simulation is carried out.Results show that the close in the frequencies of two exciting force would generate beat vibration and lead to vibration fluctuation,which is consistent with the experimental results.Combining the engine structure and working characteristics,the mechanism of beat vibra-tion resulting from the LP bio-frequency and HP fundamental frequency coupling is analyzed.The beat vibration elimination method is proposed and validated by the experiments.An effective approach is to adjust the shaft speed difference to accommodate the shaft speed ratio and eliminate the beat vibration.
NETL
NSTL
维普
万方数据