Active control of fluid flows in gas turbines

The global appetite for power and for efficient transportation can only increase as nations industrialise and the world's population grows. This application is about making engines more efficient using game changing technology that enables sophisticated computer control of engine thermodynamic cycles. This research will address the technological building blocks required for computer controlled manipulation of power generating fluid flows.

The technical difficulties of modulating engine flows can be immense but the prize for control substantial. For example, the leakage flows at the tip of a gas turbine blade and the cooling airflows in a combustion chamber contribute significantly to engine fuel burn and emissions respectively. Many such engine flows are high speed, high pressures (20bar+) and at high temperatures (500 degC+) and reside in difficult to access parts of the engine. This means that conventional valves and actuators that have moving parts are not viable due to inadequate life and slow response time.
We shall consider here a novel concept of a valve that has no moving parts and works at the pressures and temperatures normally found in gas turbines or diesel engines. The Electro-fluidic-transistor-valves to be studied in this research use small plasma discharges in combination with fundamental fluidic effects to inject or switch off jets of air when commanded. One of the goals in this research is to understand the fundamental parameters that influence the operation and performance of such devices. How fast can such devices be made to operate? And how can control engineering be used to directly manipulate on the micro scale the flow past the turbine blade tip that is the single biggest contributor aero-engine inefficiency?
To answer these questions, this ambitious proposal uses an integrated approach that will research the science of the plasma switched fluidic valves, identify the key control laws and architectures for high bandwidth flow control and then demonstrate the concept experimentally in a challenging high speed turbine application. This will require close research collaboration between control engineers and thermo-fluid specialists, a direction well aligned with EPSRC strategy for both Control Engineering and Aerodynamics disciplines. The applicants are convinced that this multi-channel approach is the best way to propel this potentially disruptive technology into CO2 saving applications.

The proposed research will make state-of-the-art advances in the field of active flow control which is now one of the key factors in driving future improvements in reducing fuel consumption in transport systems. The benefits of this research will be realised through a number of pathways to ensure greatest overarching impact across diverse set of areas and beneficiaries. The pathways will be managed by Prof. Ireland together with Rolls-Royce as the industrial partner on this grant. The main elements of the pathways are
1. Industrial impact
a. Dr Bacic will ensure that the outcomes of the research are exploited at the earliest opportunity in Rolls-Royce.
b. All investigators will engage in yearly focussed meetings with technical specialists from automotive industry

2. Academic communications: The research results will be presented at leading international conferences and high-impact scientific journals

3. Public events
a. Maintain project website to disseminate results
b. Organise an International Symposium on 'Advanced active flow control for future aerospace, automotive and energy applications'

4. Environment: The research will be utilised by the industrial partner in the first instance to improve engine fuel burn and therefore reduced CO2 emissions globally.

5. Skills & Training:
a. Project will train to 2 PhD students and 2 PDRAs to acquire advanced control, fluid dynamics, instrumentation and experimental skillsets. These skillsets are widely used across a range of industries and academia
b. Final year MEng projects will be suggested to support the research
The global impact of research will be achieved through involvement with the industrial partner (Rolls-Royce), global automotive industry engagement (Jaguar Land Rover, Formula 1 teams), and by dissemination of research through international conferences and journals.