Dynamic similarity design method for an aero-engine dualrotor test rig

13th International Conference on Motion and Vibration Control; 12th International Conference on Recent Advances in Structural Dynamics

Miao, H.^1,2 ; Zang, C.^1,2 ; Friswell, M.I.^3

Jiangsu Province Key Laboratory of Aerospace Power System, Nanjing University of Aeronautics and Astronautics, Nanjing, China^1

Collaborative Innovation Center of Advanced Aero-Engine, Nanjing, China^2

College of Engineering, Swansea University, Singleton Park, Swansea

SA2 8PP, United Kingdom^3

关键词: Aero-engine structure;    Dimensional analysis;    Dynamic characteristics;    Dynamic equivalent models;    Dynamic similarities;    Geometrical shapes;    Parametric modelling;    Unbalance response analysis;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/744/1/012109/pdf
DOI  :  10.1088/1742-6596/744/1/012109

来源: IOP

【 摘 要 】

This paper presents a dynamic similarity design method to design a scale dynamic similarity model (DSM) for a dual-rotor test rig of an aero-engine. Such a test rig is usually used to investigate the major dynamic characteristics of the full-size model (FSM) and to reduce the testing cost and time for experiments on practical aero engine structures. Firstly, the dynamic equivalent model (DEM) of a dual-rotor system is modelled based on its FSM using parametric modelling, and the first 10 frequencies and mode shapes of the DEM are updated to agree with the FSM by modifying the geometrical shapes of the DEM. Then, the scaling laws for the relative parameters (such as geometry sizes of the rotors, stiffness of the supports, inherent properties) between the DEM and its scale DSM were derived from their equations of motion, and the scaling factors of the above-mentioned parameters are determined by the theory of dimensional analyses. After that, the corresponding parameters of the scale DSM of the dual-rotor test rig can be determined by using the scaling factors. In addition, the scale DSM is further updated by considering the coupling effect between the disks and shafts. Finally, critical speed and unbalance response analysis of the FSM and the updated scale DSM are performed to validate the proposed method.