EXPERIMENTAL VERIFICATION OF THE SIMPLIFICATION METHOD OF A SPECIFIC TYPE OF DUAL-ROTOR AERO-ENGINE SYSTEM DYNAMIC MODEL

The structure of aero-engines is complex, and the dynamic characteristics are changeable. A reasonable dimensionality simplified model is a crucial issue for studying the dynamics of aero-engines. This paper takes a specific type of aero-engine dual-rotor testbed as the research object and establishes a solid finite element model. The rotor disc, shaft, and support structure are simplified. A simplified model of the dual-rotor aero-engine system is based on the method of structural dimensionality reduction and verifies the dynamics of the dimensionality reduction model through experiments characteristics, thus verifying the effectiveness of the simplified model. An aero-engine dual-rotor system's modal shape and natural frequency are measured experimentally, and the model error is less than 11%. The first-order critical speed error of the simplified model is less than 7.7% when the first-order critical speed is measured by superharmonic resonance. The results show that the solid finite element model and structural dimension reduction methods of the dual-rotor complete machine system are accurate and effective. The verified simplified model of the dual-rotor aero-engine system provides a basis for studying dynamic characteristics.