179 / 2021-03-31 18:43:40

Investigation on dynamic characteristics of a dual-rotor-casing-bearing coupled system considering rub-impact fault in presence of non-uniform initial gap

Dual-rotor,non-uniform initial gap,rub-impact fault,dynamic characteristic

Due to coating inhomogeneity, coating wear, machining error and thermal deformation of parts, the initial gap between blade tips and casing appears non-uniform. On the other hand, a dual-spool arrangement is a common configuration adopted in aero engines to pursue higher thrust-weight ratio and better aerodynamic stability. To lower vibration noise and enhance overall performance of aero engines, it is essential for engineers to determine dynamic characteristics of dual-rotor systems in advances. Under this circumstance, the purpose of this paper is to predict the vibration behaviors of a dual-rotor-casing-bearing coupled system with rub-impact fault in presence of non-uniform initial gap. Firstly, the governing equations of the system are derived by the finite element method. For the contact analysis, a novel contact force model is utilized and the effect of non-uniform initial gap is taken into account. On this basis, the dynamic responses are obtained by the numerical simulation and then are analyzed by the waveforms, whirling orbit and spectrum. Finally, the sensitivity analysis of rub-impact parameters is conducted as well.