Double Wall Effusion Turbine Cooling: The impact of deterministic unsteadiness and transients.

Lead Research Organisation: University of Oxford
Department Name: Engineering Science

Abstract

This project will seek to determine the impact of flow unsteadiness that emanates from wake passing and changes in the flow field experienced by the rotor blades positioned downstream of the nozzle guide vanes. The combustor can also develop significant turbulence and flow unsteadiness. The work will evaluate the impact of unsteadiness on the effectiveness of the active cooling system to be implemented in the double wall effusion cooled turbine blade. The research will use both computational fluid dynamics and low speed experiments in a large-scale wind tunnel. This research will explore the use of novel techniques for generating unsteadiness including fluidic devices as well squirrel cage or rotating bar apparatus that previous studies have employed. The aim is to better represent the necessary bandwidth to study this phenomenon and will reduce the experimental complexity involved in the aforementioned apparatus.

This research will provide unique data on the effects of ingestion on film cooling, as well as the threshold necessary in the double wall system to prevent ingestion. The impact of this research will be to enable to design of a high-pressure turbine blade with significant reduction in coolant supply. Coolant, whilst necessary, is a source of loss and the reduction of its injection into the working fluid of a gas turbine engine can have dramatic effects on the efficiency and power of the machine. An understanding of the likely response of the double wall system to engine representative unsteadiness is therefore pertinent to the assessment of double wall performance.

Planned Impact

1. Impact on the UK Aero-Propulsion and Power Generation Industry
The UK Propulsion and Power sector is undergoing disruptive change. Electrification is allowing a new generation of Urban Air Vehicles to be developed, with over 70 active programmes planning a first flight by 2024. In the middle of the aircraft market, companies like Airbus and Rolls-Royce, are developing boundary layer ingestion propulsion systems. At high speed, Reaction Engines Ltd are developing complex new air breathing engines. In the aero gas turbine sector Rolls-Royce is developing UltraFan, its first new architecture since the 1970s. In the turbocharger markets UK companies such as Cummins and Napier are developing advanced turbochargers for use in compounded engines with electrical drive trains. In the power generation sector, Mitsubishi Heavy Industries and Siemens are developing new gas turbines which have the capability for rapid start up to enable increased supply from renewables. In the domestic turbomachinery market, Dyson are developing a whole new range of miniature high speed compressors. All of these challenges require a new generation of engineers to be trained. These engineers will need a combination of the traditional Aero-thermal skills, and new Data Science and Systems Integration skills. The Centre has been specifically designed to meet this challenge.

Over the next 20 years, Rolls-Royce estimates that the global market opportunities in the gas turbine-related aftercare services will be worth over US$700 billion. Gas turbines will have 'Digital Twins' which are continually updated using engine health data. To ensure that the UK leads this field it is important that a new generation of engineer is trained in both the underpinning Aero-thermal knowledge and in new Data Science techniques. The Centre will provide this training by linking the University and Industry Partners with the Alan Turing Institute, and with industrial data labs such as R2 Data Labs at Rolls-Royce and the 'MindSphere' centres at Siemens.

2. Impact on UK Propulsion and Power Research Landscape
The three partner institutions (Cambridge, Oxford and Loughborough) are closely linked to the broader UK Propulsion and Power community. This is through collaborations with universities such as Imperial, Cranfield, Southampton, Bath, Surrey and Sussex. This will allow the research knowledge developed in the Centre to benefit the whole of the UK Propulsion and Power research community.

The Centre will also have impact on the Data Science research community through links with the CDT in Data Centric Engineering (DCE) at Imperial College and with the Alan Turning Institute. This will allow cross-fertilization of ideas related to data science and the use of advanced data analytics in the Propulsion and Power sectors.

3. Impact of training a new generation of engineering students
The cohort-based training programme of the current CDT in Gas Turbine Aerodynamics has proved highly successful. The Centre's independent Advisory Group has noted that the multi-institution, multi-disciplinary nature of the Centre is unique within the global gas turbine training community, and the feedback from cohorts of current students has been extremely positive (92% satisfaction rating in the 2015 PRES survey). The new CDT in Future Propulsion and Power will combine the core underlying Aero-thermal knowledge of the previous CDT with the Data Science and Systems Integration skills required to meet the challenges of the next generation. This will provide the UK with a unique cohort of at least 90 students trained both to understand the real aero-thermal problems and to have the Data Science and Systems Integration skills necessary to solve the challenges of the future.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/S023003/1 01/10/2019 31/03/2028
2779317 Studentship EP/S023003/1 01/10/2022 30/09/2026 Emilios Lemonaris