Introduction
The ultimate ambition of the LITECS research programme is to reduce the environmental impact of aviation and industrial gas turbine engines (GTEs). Aviation contributes <2% of greenhouse gases (less so now) but, in line with strategies for a low carbon future, the entire industry is committed to achieving challenging emissions reduction targets, including oxides of nitrogen and soot. Manufacturers of industrial / power generating GTEs are similarly committed.
Serious emissions reduction can only come from better understanding and modelling of the combustion and emissions generation processes and the role of fuels. At present, modelling provides the best insights we have to understanding the relevant processes within the engine, supported by some, but limited, contribution from qualitative experimental characterisation. In this programme, we are developing several non-disruptive quantitative chemical and particulate species measurement instruments to enable accurate and detailed characterisation of GTE combustion and exhaust species (gaseous and particulate), both spatially and in quasi-real time. The final integrated multi-species instruments will be installed and used in world leading combustion research facilities, bringing transformational quantitative measurement capability to the problem. Experimental data sets from these will inform new understanding and improve, test and perhaps validate new models of combustion and emissions generation processes. The outcomes will lead to advancing strategies to deliver improved engine and fuel technologies for reduced emissions.
The research is being delivered by six university partners, led by Professor Walter Johnstone of the University of Strathclyde, and supported financially and in an advisory capacity by five industry partners including two GTE manufacturers – end users and three technology suppliers. Guidance and advice are provided by the Industry Advisory Group (IAG comprising Engineers from our each of our Industry partners) who attend all quarterly review meetings and an International Steering Board (ISB) of ten technical experts in the field who meet with the core management group and the IAG once per annum. The ISB is chaired by Dr Simon Weeks, Chief Technology Officer of the Aerospace Technology Institute.
The Project details are as follows:
- Type: EPSRC Programme Grant
- Funding: £8M from EPSRC, industry and the various institutions in the consortium.
- Project leader: Professor Walter Johnstone of the University of Strathclyde
- Academic Partners: Strathclyde (Lead), Edinburgh, Manchester, Southampton, Loughborough and Sheffield universities
- Industry Partners: Rolls-Royce (aero-engine manufacturer), Siemens (industrial gas turbine engine manufacturer), OptoSci Ltd. (a laser instrumentation manufacturer), M Squared Lasers and Tracerco (imaging systems manufacturers).
Scope
Ideally, the GTE industries need non-intrusive, in situ, spatially and temporally resolved measurements of soot, CO2, CO, H2O, NO, NO2, SOx, N2O and formaldehyde plus temperature and stoichiometry in both the exhaust plume and combustion zones of GTEs. This is beyond the scale of a single project in both extent and risk. In the £2.8M EPSRC / Industry project, Fibre Laser Imaging of Turbine Engine Exhaust Species (FLITES), we demonstrated CO2 tomographic imaging in the exhaust plume of a full-scale commercial GTE. Tuneable diode laser spectroscopy (TDLS) measured the path-integrated concentration in each path of a multi-beam (126) tomographic system. Building on this achievement, this programme is focused on the species and quantities deemed by the industry to be of highest priority, i.e. CO2, CO, H2O, NO, NO2, plus temperature and stoichiometry. Establishing several new non-intrusive, in situ, time-resolved, 2D, imaging systems for simultaneous quantification of multiple gases (CO2, CO, H2O), soot and temperature (providing stoichiometry) in the exhausts and combustion chambers of GTEs (Strathclyde, Edinburgh and Manchester Universities, supported by Southampton delivering new optical fibre systems). In addition, single path systems are being developed and multi-path versions investigated for NO and NO2. The instrumentation will be installed and used at the world leading National Centre for Combustion and Aero-thermal Technologies (NCCAT, Loughborough University) and Low Carbon Combustion Centre (LCCC, Sheffield University), enabling, for the first time, spatially and temporally resolved measurements of the evolution of key combustion species and the determination of temperature maps and stoichiometry. Measurements will be made under a range of engine conditions (temperature, pressure, fuel/air mixtures etc.) for standard and alternative fuels. Through immediate and future engagement with the wider combustion / modelling community, data sets from such measurements will inform the understanding and modelling of combustion and emissions generation, advancing strategies for emissions reduction.
Impact
During the programme and far into the future, the new measurement systems installed at NCCAT and LCCC will be a platform for new research programmes to inform understanding of combustion and emissions generation processes. The outcomes and access to the systems themselves will be available to, and will directly benefit, all researchers working in these areas, whether involved in experimental investigation or in simulation, where experimental measurements can be used to inform models. We are seeking active engagement with these communities and proposals for experimental programmes to support the community will be welcomed and implemented if possible.
Economic impact is ensured by the support and commitment of our industry partners including the provision of specialist engineering expertise and advisory support, access to state of the art engine test facilities, testing of new systems on commercial GTEs and specialist equipment for testing. Rolls-Royce have arranged up to five weeks of access to full scale commercial engine test facilities at the Spanish Institute for Aerospace Technology (INTA) and Siemens are providing access to commercial engine test facilities at their Lincoln facility, both intended to expedite impact. The consortium benefit greatly from the GTE emissions, combustion and fuels expertise on our advisory group from Rolls-Royce (2 staff), Siemens (1) and a former Shell fuels expert. Rolls-Royce have also committed to support any extension of LITECS and other appropriate spin-off research programmes.
Benefits arising into the future include new capabilities in combustion process modelling, lower cost engine diagnostics, lower cost fuels evaluation, emissions reduction and advances in engine and fuel technologies for reduced emissions. In the longer term they will bring improved and lower cost emissions monitoring (engine certification), routine use in operational engine monitoring and, possibly, improved engine control.
