Modeling and Contribution Analysis of Vibration Transfer Paths for a Dual-Rotor Aeroengine

In order to study the vibration transfer characteristics of a dual-rotor aeroengine system, an aeroengine system dynamic model containing high- and low-pressure rotors as well as inner and outer casings is established. The Newmark-beta method is used to solve the developed model and obtain the dynamic characteristics of the system. This paper proposes a dynamic model and operational transfer path analysis (OTPA) method to analyze the vibration transfer path of a dual-rotor aeroengine system. The concept of insertion loss is introduced, and Cramer's rule is used to improve the computational efficiency of dynamic equations for systems with variable stiffness and damping matrices. The vibration contribution of three vibration transfer paths is calculated separately. A dual-rotor-casing vibration transfer path test bench is built to make experimental research on vibration transfer characteristics and verify the accuracy of simulation results. The results indicated that among the three vibration transfer paths, the first vibration transfer path has the highest contribution to the vibration of the outer casing of the system. Due to the nonlinear superposition of responses, the overall response amplitude of the outer casing shows an increasing trend as the rotational speed ratio increases. The contribution rate of the three paths does not change with the rotational speed, and the vibration contribution of each path at different rotational speed ratios fluctuates slightly near the mean.