Abstract
Unraveling the flow physics pertaining to hot gas ingress in turbines is crucial in enabling designers to realize global decarbonization targets in aerospace. A turbine rim seal is fitted at the periphery of the rotor–stator cavity to minimize the ingress of annulus gas, which detrimentally affects cycle’s efficiency. The inherent unsteadiness in rim seal flows, arising from shear gradients between contiguous flow paths, introduces a consequential, yet presently unestablished, influence on sealing characteristics. A single-stage axial turbine facility in conjunction with an aeroengine architecture is employed to assess the steady and unsteady sealing characteristics of a range of industrially relevant rim seals. Time-averaged measurements of gas concentration and swirl, acquired over a range of flow coefficients (C F), exhibited an inverse relationship between sealing performance and the purge-mainstream swirl difference (Db). Spectral analysis of unsteady pressure signals revealed an associated unsteadiness, induced by the strength of the annulus-cavity interaction. Across all C F, a low-frequency harmonic range consistently displayed proportionality between spectral activity and Db. Thus, a relationship between steady and unsteady characteristics was established. Examining a series of rim seal configurations with varying radial clearances signified that sealing performance was predominantly influenced by the radially outermost clearance. The configurations exhibiting superior performance presented heightened spectral activity, ascribed to an increased radial purge mass flux and establishing a definite relationship with concurrent steady measurements.
| Original language | English |
|---|---|
| Article number | 041031 |
| Number of pages | 12 |
| Journal | Journal of Engineering for Gas Turbines and Power |
| Volume | 147 |
| Issue number | 4 |
| Early online date | 11 Dec 2024 |
| DOIs | |
| Publication status | Published - 30 Apr 2025 |
Data Availability Statement
Due to confidentiality agreements with research collaborators, supporting data can only be made available to bona fide researchers subject to a nondisclosure agreement. Details of how to request access are available at the University of Bath data archive.Acknowledgements
The authors would like to acknowledge the technical expertise and support of Andrew Langley and Sam L'esteve who enabled the continued running of the experimental facility and its instrumentation. The authors would also like to thank Safran Aircraft Engines, especially Clément Jarrossay, Damien Bonneau, and Fatoumata Bintou Santara for their close collaboration and for providing an industrial perspective to this study, in addition to funding this work in its entirety.Funding
The authors would like to acknowledge the technical expertise and support of Andrew Langley and Sam L\u2019esteve who enabled the continued running of the experimental facility and its instrumentation. The authors would also like to thank Safran Aircraft Engines, especially Cl\u00E9ment Jarrossay, Damien Bonneau, and Fatoumata Bintou Santara for their close collaboration and for providing an industrial perspective to this study, in addition to funding this work in its entirety.
| Funders | Funder number |
|---|---|
| Safran Aircraft Engines | |
| Fatoumata Bintou Santara |
Keywords
- aeroengine turbine rim seals
- cavity flows
- clearance changes
- spectral analysis
- turbulent flows
ASJC Scopus subject areas
- Nuclear Energy and Engineering
- Fuel Technology
- Aerospace Engineering
- Energy Engineering and Power Technology
- Mechanical Engineering