Influence of structural features on oil film dynamics of elastic ring-supported rotor systems

Abstract

Elastic ring squeeze film dampers (ERSFDs) are widely used in high-speed aero-engine rotor systems for multi-critical speed vibration control. This study proposes a time-efficient fluid-structure interaction framework combining elastic ring deformation modeling with oil film hydrodynamics. A fast-solving iterative oil film analysis, capturing rotor deflection, ring deformation, fluid flow, and orifice throttling effects, is conducted. Experimental validation on a custom ERSFD rotor test rig confirms the variation tendency of the proposed methodology. Parametric studies reveal that increasing bulge count enhances radial stiffness but reduces damping by restricting circumferential flow. Optimal oil film thickness improves damping, while excessive thickness increases flow impedance. Orifice diameter impacts damping speed-dependently: larger diameters enhance low-speed damping but degrade it at higher speeds, with minimal effects from orifice distribution. An optimal design approach of a flexible rotor system with multi-ERSFD support based on the parametric analysis results, reducing vibration amplitudes at critical speeds by over 40%, as validated in simulated power turbine rotor tests, further proves the accuracy of the proposed methodology and its application value in engineering.