Research On Flexible Rotor Dynamic Balancing And Rotor Dynamical Characteristic

Rotor unbalancing is one of the main causes of vibration and noise in aero-engine, especially in micro-turbojet engine, which affects work performance and fatigue life directly. So it is of engineering value to research flexible rotor dynamic balancing. Least square influence coefficient method is improved in the paper. Restrained adjust mass least square method and least square method based on genetic algorithm are put forward. The former can be used to reduce adjust mass not more than allowable mass, and the latter can optimize balancing adjust mass and residual vibration value altogether. Flexible rotor dynamic balancing tests are performed in ZT-3 rotor vibration simulation test-bed to be verified the advantage of the least square method based on genetic algorithm. Balance adjust mass would be much large if balance planes are non-independent, which leads balancing to be failed. Gram-Schmidt orthogonalization decomposition method and singular value decomposition method can be used to eliminate and avoid non-independent balance planes. When nonlinear-bearing is considered, nonlinear-bearing rotor dynamic balancing method based on the principle of equivalent linearization in vibration area is presented, by which equivalent stiffness of bearing under the balancing speed can be gained; Rotor dynamic balancing tests are performed based on the theory of dynamic balancing. Centripetal turbo and centrifugal compressor of micro-engine are balanced practically. Rotor critical speed should be calculated, because flexible rotor dynamic balancing ought to be performed nearby critical speed. Program is compiled to calculate critical speed based on the theory of finite element method. ANSYS software is also used to calculate critical speed compared with the program. At last, imbalance response of micro-engine Sonic8000 is calculated to make sure of the balancing precision.