Improved vibration performance of a nonlinear rotor-seal system with modified labyrinth seals by an interpolating database method

Abstract

Traditional studies for seal evaluation primarily focused on rotordynamic coefficients. We previously introduced two innovative labyrinth seals, the diaphragm labyrinth seal (DLS) and hole diaphragm labyrinth seal (HDLS), featuring enhanced rotordynamic and leakage characteristics. To delve into the dynamic response of these circumferentially discontinuous seals, which cannot be reduced to a 2D model, an interpolation database method (IDM) is proposed. Improved vibration performances are obtained in a nonlinear rotor-seal system with modified labyrinth seals. The Muszynska seal force model is compared with IDM for verification of accuracy. Comprehensive insights into the system's behavior were provided through metrics like the maximum Lyapunov exponent, time-domain waveform, spectrogram, Poincaré, displacement orbits, and phase maps. Results underscored IDM's accuracy for circumferentially continuous seals vis-a-vis Muszynska's model, showcasing exceptional solving abilities for discontinuous seals. Local subharmonic vibrations in rotor-DLS and rotor-HDLS systems were identified. Notably, HDLS demonstrated a 56.6% reduction in maximum amplitude compared to labyrinth seal (LS) and a 24.6% reduction compared to DLS. Maximum Lyapunov exponent outcomes emphasized HDLS’s superior stability among the three labyrinth seal types in rotor-seal system. Especially, HDLS maintained stability across diverse unbalanced mass conditions, further highlighting its versatility and application potential.