GTF发动机高速柔性转子系统支点动载荷控制方法

Bearing dynamic load control method for high speed flexible rotor system of GTF engine

针对齿轮驱动涡扇(geared turbofan,GTF)发动机高速柔性转子系统,建立力学模型与有限元模型,在分析支点动载荷组成与特征的基础上,提出临界转速支点动载荷控制方法与模态振型控制评估参数。通过控制临界转速模态振型中大质量惯性部件角向模态位移,降低转子对惯性主轴倾斜旋转惯性激励敏感度,以及控制弯曲振型节点位置靠近支点,实现高速柔性转子弯曲振型临界转速下支点动载荷控制。结果表明,通过在低压涡轮采用双支点布局,以及优化低压压气机轴颈刚度,可实现上述临界转速模态振型有效控制,转子弯曲振型临界转速下支点动载荷可降低约14%~65%,验证了本文方法有效性。

The mechanical model and finite element model of the high speed flexible rotor system of GTF(geared turbofan) engine were established.Based on analysis of the composition and characteristics of bearing dynamic load,the critical speed bearing dynamic load control method and modal shape control evaluation parameters were proposed.In this method,the angular motion of the large inertial component in the critical speed modal shape was controlled,the sensitivity of the rotor to couple unbalance excitation was reduced,and the node position of the bending modal shape was controlled close to the bearing,so as to realize the bearing dynamic load control under the lateral bending critical speeds of the high speed flexible rotor system.The results showed that the above critical speed modal shape control can be achieved by adopting the double supporting layout around the low-pressure turbine and optimizing the conical shell stiffness of the low-pressure compressor.The effectiveness of bearing dynamic load control method was verified by the 14%-65% reduction of bearing dynamic load under the lateral bending critical speeds.