GTF 发动机高速柔性转子系统支点动载荷控制方法

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.