Brush seal Resistance to Inlet Swirl and Transient Loading Effects (BRISTLE)
Lead Research Organisation:
University of Surrey
Department Name: Mechanical Engineering Sciences
Abstract
Air and other travel must become more energy-efficient to meet ambitious environmental targets set by the UK government and internationally. One key technology, which is important in determining efficiency and fuel burn, is engine seals. Challenges remain in deploying seals in the highest value locations, and in developing highly efficient novel system architectures which are enabled by reliable seals.
Advanced shaft seals with compliant flexible elements can offer several advantages over the prevalent state-of-the-art, the labyrinth seal. These include increased tolerance of radial movements and shaft contact, and reduced leakage for a significantly reduced weight and space envelope. This research seeks to demonstrate that it is possible to expand the operating range and improve the robustness of one seal type, the brush seal, such that this can be used more widely in rotating machinery. Such sealing solutions can be used to improve the efficiency of current products, and also apply to future concepts including those with alternative working fluids and systems which are more electric.
The Surrey University Brush Seal Iterative Simulator (SUBSIS) is able to capture the complex fluid-structure interaction within these adaptable seals, and shall be modified to investigate the resistance of the brush seal to high levels of inlet swirl consistent with those found at high shaft speed locations, for conventional and pressure-balanced brush seal configurations. The updated method will also allow for an assessment of the bristle-rotor tracking and seal leakage properties of these seal types under transient shaft incursion, associated with an offset (sweeping) or distorted rotor. These methods can be adapted to simulate any seal type with flexible elements in future research. Via academic and industrial collaboration, this work will contribute a significant forward step in delivering the sealing and power and propulsion technologies of the future.
Advanced shaft seals with compliant flexible elements can offer several advantages over the prevalent state-of-the-art, the labyrinth seal. These include increased tolerance of radial movements and shaft contact, and reduced leakage for a significantly reduced weight and space envelope. This research seeks to demonstrate that it is possible to expand the operating range and improve the robustness of one seal type, the brush seal, such that this can be used more widely in rotating machinery. Such sealing solutions can be used to improve the efficiency of current products, and also apply to future concepts including those with alternative working fluids and systems which are more electric.
The Surrey University Brush Seal Iterative Simulator (SUBSIS) is able to capture the complex fluid-structure interaction within these adaptable seals, and shall be modified to investigate the resistance of the brush seal to high levels of inlet swirl consistent with those found at high shaft speed locations, for conventional and pressure-balanced brush seal configurations. The updated method will also allow for an assessment of the bristle-rotor tracking and seal leakage properties of these seal types under transient shaft incursion, associated with an offset (sweeping) or distorted rotor. These methods can be adapted to simulate any seal type with flexible elements in future research. Via academic and industrial collaboration, this work will contribute a significant forward step in delivering the sealing and power and propulsion technologies of the future.
Publications
Phan H
(2024)
Insights Into Frictional Brush Seal Hysteresis
in Journal of Engineering for Gas Turbines and Power
Phan H
(2025)
Modeling of Frictional Interbristle Contact in Brush Seals With Shaft Radial Movements
in Journal of Engineering for Gas Turbines and Power
| Description | Brush seals were successfully modelled with inter-bristle and bristle backing ring friction culminating in a tool which largely replicates experimental trends and which may be used for future research. Aerodynamic grooves were developed and numerically demonstrated for flow conditioning and inlet swirl reduction in sealing applications, since swirl may be detrimental to sealing performance and component integrity. |
| Exploitation Route | In the form of further research and incorporation of rules, tools and methods. Groove designs may be adopted for testing immediately in industry. This work is applicable to both gas and steam turbines. |
| Sectors | Aerospace Defence and Marine Energy Manufacturing including Industrial Biotechology |
| Title | Surrey University Brush Seal Iterative Simulator (SUBSIS) |
| Description | Mechanical model development for use in fluid-structure interaction problems updated to incorporate frictional contact between structural elements. |
| Type Of Material | Computer model/algorithm |
| Year Produced | 2024 |
| Provided To Others? | Yes |
| Impact | Improved understanding of brush seal behaviour considering the importance of friction in determining deflection response to aerodynamic loading. |
| URL | https://doi.org/10.1115/1.4067863 |
| Description | UK Manufacturing Collaboration |
| Organisation | Cross Manufacturing Company (1938) Ltd |
| Country | United Kingdom |
| Sector | Private |
| PI Contribution | Our team is developing state of the art models to capture the dynamics of brush seals, which are severely lacking in the design phase, and to provide physical insight into the operation of complex gas turbine sealing solutions so as to improve their robustness. |
| Collaborator Contribution | We are partnering with leading UK manufacturers to be able to deliver real impact. The in-kind support (equivalent to £50,000 over the duration of the project) allows for quarterly meetings with Cross Manufacturing and Rolls-Royce company specialists, and for the provision of test data for model validation. The in-kind support from Rolls-Royce plc, for which this technology is applicable to both civil and defence applications, allows for the exchange of information related to the end use and operating environments of sealing components. In terms of impact, this collaboration will serve to improve the reputation and future revenues of Cross-Manufacturing and Rolls-Royce through the sale of higher quality, higher efficiency and more reliable sealing and propulsion system solutions. The collaboration with Rolls-Royce will help to ensure the following: + A platform for the internal dissemination of project outcomes, + A potential route to market for advanced brush seal design concepts delivered by the project. |
| Impact | Meetings held at partner site in Cross Devizes, Rolls-Royce Bristol, and Rolls-Royce Derby to discuss technical progress and obtain feedback. |
| Start Year | 2022 |
| Description | UK Manufacturing Collaboration |
| Organisation | Rolls Royce Group Plc |
| Country | United Kingdom |
| Sector | Private |
| PI Contribution | Our team is developing state of the art models to capture the dynamics of brush seals, which are severely lacking in the design phase, and to provide physical insight into the operation of complex gas turbine sealing solutions so as to improve their robustness. |
| Collaborator Contribution | We are partnering with leading UK manufacturers to be able to deliver real impact. The in-kind support (equivalent to £50,000 over the duration of the project) allows for quarterly meetings with Cross Manufacturing and Rolls-Royce company specialists, and for the provision of test data for model validation. The in-kind support from Rolls-Royce plc, for which this technology is applicable to both civil and defence applications, allows for the exchange of information related to the end use and operating environments of sealing components. In terms of impact, this collaboration will serve to improve the reputation and future revenues of Cross-Manufacturing and Rolls-Royce through the sale of higher quality, higher efficiency and more reliable sealing and propulsion system solutions. The collaboration with Rolls-Royce will help to ensure the following: + A platform for the internal dissemination of project outcomes, + A potential route to market for advanced brush seal design concepts delivered by the project. |
| Impact | Meetings held at partner site in Cross Devizes, Rolls-Royce Bristol, and Rolls-Royce Derby to discuss technical progress and obtain feedback. |
| Start Year | 2022 |
| Description | Rolls-Royce Annual Review - Bristol |
| Form Of Engagement Activity | A formal working group, expert panel or dialogue |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Postgraduate students |
| Results and Impact | Dissemination of seals research findings and progress concerning both de-swirl technologies and understanding the effect of internal friction on performance, to a substantial group of industry specialists and academia in Europe, the United Kingdom and the United States. Positive feedback received and discussions about potential future work and collaboration. |
| Year(s) Of Engagement Activity | 2024 |
| Description | Rolls-Royce Annual Review Derby |
| Form Of Engagement Activity | A formal working group, expert panel or dialogue |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Industry/Business |
| Results and Impact | Dissemination of seals research findings and progress concerning both de-swirl technologies and understanding the effect of internal friction on performance, to a substantial group of industry specialists and academia in Europe, the United Kingdom and the United States. Positive feedback received and discussions about potential future work and collaboration. |
| Year(s) Of Engagement Activity | 2023 |
| Description | Technical Review Meeting and Strategy Session with Cross Manufacturing and Rolls-Royce |
| Form Of Engagement Activity | A formal working group, expert panel or dialogue |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Professional Practitioners |
| Results and Impact | Technical Review Meeting and Strategy Session with Cross Manufacturing and Rolls-Royce - discussion of work conducted, interesting findings, opportunities for further work and opportunities for future projects and funding. |
| Year(s) Of Engagement Activity | 2024 |
| Description | Visit and Research Discussion |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Industry/Business |
| Results and Impact | Preliminary research discussion, presentation of initial findings and work scoping with the leading compliant seals manufacturer in the UK, Cross Manufacturing. |
| Year(s) Of Engagement Activity | 2022 |