Dynamic Characterization of an Adaptive Film-Riding Seal

Joshua Bird, Patrick S. Keogh, Carl M. Sangan, Aaron Bowsher, Peter Crudgington, James A. Scobie

Research output: Chapter or section in a book/report/conference proceedingChapter in a published conference proceeding


Shaft seals control the leakage of fluid between areas of high pressure and low pressure around rotating components inside turbomachinery. Static seals are often subject to damaging rubs with the shaft, caused by assembly misalignments and rotordynamic vibrations during operation. Adaptive seals aim to reduce leakage flows whilst minimizing wear. The Film Riding Pressure Actuated Leaf Seal (FRPALS) is one such design which utilizes a large installation clearance and is blown down towards the shaft under pressure.

This paper presents a numerical model which can be used in the design and development of adaptive shaft seals, validated by experimental data from the literature. The model uses a modified version of the Reynolds equation to predict the dynamic, frequency-dependent stiffness and damping coefficients of the fluid film. The dynamic coefficients have been solved for different operational clearances and pressure differences to generate coefficient maps. These maps have been incorporated into a blow down model with compliant mechanical leaves to predict the transient translational and angular displacement paths of the FRPALS when subject to an increasing pressure drop.

The blow down model has been compared against experimental measurements collected from a specially designed test facility for the characterization of shaft seal performance. Eddy current probes were used to measure the displacement paths of the FRPALS with the experimental values showing that the model can accurately predict the dynamic movement of the seal when subject to a pressure difference.
Original languageEnglish
Title of host publicationStructures and Dynamics - Aerodynamics Excitation and Damping; Bearing and Seal Dynamics
Subtitle of host publicationBearing and Seal Dynamics
Number of pages15
ISBN (Electronic)9780791887059
Publication statusPublished - 28 Sept 2023
EventASME Turbo Expo 2023: Turbomachinery Technical Conference and Exposition - Boston, Massachusetts, USA
Duration: 26 Jun 202330 Jun 2023

Publication series

NameProceedings of the ASME Turbo Expo


ConferenceASME Turbo Expo 2023: Turbomachinery Technical Conference and Exposition


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