Investigation on rub-impact response characteristics of gas generator rotor system under external excitation

Gas turbine engines of tanks, which are land-based derivatives of aero-turboshaft engines, share core gas generator rotor structures but face significantly higher external impact loads due to combat environments, require enhanced dynamic performance, especially in resisting rotor-casing rub-impact response. To address this, a dynamic model of the rotor system is established, employing the equivalent ring principle for the circular arc end-teeth connection structure, the differential quadrature finite element method (DQFEM) for variable-section blades, and the lumped parameter method for modeling the disks. The supporting system, which incorporates squeeze film dampers (SFDs), is constructed based on oil film and short bearing theory. Using Coulomb's friction law, a blade-casing rub-impact dynamic model is developed. The accuracy of the model is verified through modal testing. A parametric study is conducted to explore the influence of impact load amplitude, support damping, blade-casing stiffness and clearance, and unbalanced mass on the rub-impact response of the rotor-casing system. The proposed model and findings are applicable to both vehicle-mounted gas turbines and aero-turboshaft engine rotors. The results are useful in the design and optimization of vehicle-mounted gas turbines under high external impact loads.