齿轮传动风扇发动机转子系统结构与动力学分析

考虑齿轮传动风扇发动机(GTF)风扇转子与低压转子的耦合关系,提出了转子系统简化整体模型,针对该模型给出了GTF发动机转子系统的临界转速计算方法.揭示了整体模型与单转子模型临界转速计算结果的差异,以及典型力学特征参数对GTF转子系统临界转速与模态特征的影响.计算结果表明:相比考虑耦合关系的整体模型,将风扇转子与低压转子分开计算会导致转子系统固有频率值偏移及部分临界转速丢失;齿轮箱安装支承刚度增大会使得系统临界转速上升,保持安装刚度大小在106N/m量级以下可使系统动力特性较优;传扭轴段刚度与齿轮径向啮合刚度对系统动力特性影响较小. 

Structure and dynamics analysis of rotor system in geared turbofan engine

Taking the coupling between fan and low-pressure rotors of geared turbo fan (GTF) engine into consideration, a simplified model of rotor system and a critical speed calculation method for the model were proposed. Differences of critical speed results between the overall rotor system and the single rotor system were clarified. Influence of typical parameters on critical speed and dynamics of the rotor system was discussed. From the results, calculating the fan and low-pressure rotors separately causes deviation of natural frequency and loss of critical speed. Increase of the gearbox support stiffness leads to rise of critical speeds, while keeping the stiffness value below 10⁶N/m may provide better dynamic characteristics. The flexural rigidity of the torque transmission shaft and radial stiffness of the gearbox have less impact on system's dynamic characteristics.