NON-LINEAR FLUTTER ANALYSIS OF LABYRINTH SEALS
Publicated to:Proceedings Of The Asme Turbo Expo. 8-A - 2022-01-01 8-A(), DOI: 10.1115/GT2022-82142
Authors: Corral R; Greco M; Matabuena L
Affiliations
Abstract
A simple nonlinear model to describe labyrinth seal flutter has been developed to assess the aeromechanic stability of straight-through labyrinth seals subjected to large gap variations. The model solves the one-dimensional integral mass, momentum, and energy equations of the seal for a prescribed motion numerically until a periodic state is reached. The model accounts for the effect, previously neglected, of high clearance variations on the stability. The results show that when the vibration amplitudes are small, the work-per-cycle coincides with the prediction of the Corral and Vega model (2018, “Conceptual Flutter Analysis of Labyrinth Seals Using Analytical Models. Part I: Theoretical Background, ASME J. Turbomach.140(10), pp. 121006) and Corral et al. (2021, “Higher-Order Conceptual Model for Seal Flutter”, ASME J. Turbomach. 143(7), pp.071006), but for large vibration amplitudes nonlinearities alter the stability limit. In realistic cases, when the discharge time of the seal is much longer than the vibration period, the nonlinear effects are significant and tend to increase the unstable range of operating conditions. Furthermore, seals supported either on the high-pressure or low-pressure sides, stable for small vibration amplitudes, can destabilise when the vibration amplitude increases. The linear stability, though close in many situations to the nonlinear threshold, is not conservative, and attention must be paid to nonlinear effects.
Keywords
Quality index
Impact and social visibility
Leadership analysis of institutional authors
This work has been carried out with international collaboration, specifically with researchers from: Netherlands.
There is a significant leadership presence as some of the institution’s authors appear as the first or last signer, detailed as follows: First Author (CORRAL GARCIA, ROQUE) .
the author responsible for correspondence tasks has been GRECO, MICHELE.