The Impact of Uncertainty on Zero-Emission Aircraft Design

As the aviation industry is looking to reduce its climate footprint, progress is hindered by a lack of consensus on which pathways are most likely to lead to fast, impactful results. This is underpinned by a discrepancy in views regarding the timeframes, costs and climate effects associated with the development and implementation of novel aviation technologies and fuels, amongst other factors. The discrepancy in views, in turn, is caused by the absence of a formalised way of dealing with aviation-related uncertainties, which are present at all scales within the aviation system.
The key objective of the project is the identification and quantification of uncertainties within the aviation industry in a systematic manner, with a view to creating an uncertainty assessment framework that could be used in the development of roadmaps to achieve net zero aviation by 2050.
The project aims to understand and categorise the main types of uncertainty that are present within aviation through the analysis of historical and literature-based case studies concerning the development of aviation technologies. Metrics will be developed to assess the impact of each uncertainty type in a manner that enables different types of uncertainties to be compared despite their different characteristics. In parallel, comprehensive graphs outlining interactions between the main stakeholders involved in the aviation system, together with the technical and socioeconomical factors that drive their actions, will be created. Uncertainties will be mapped on these graphs in order to understand their propagation throughout the system at different scales, as well as the way each type of uncertainty influences the others.
By quantifying the effect of each uncertainty in isolation, together with the effect of interactions between multiple uncertainty types, their overall impact on the design, development and implementation of new aviation technologies will be determined. This could serve to highlight the combinations of technological, operations and policy strategies that are most likely to succeed in reducing aviation-related emissions in a timely, cost-effective and high-impact manner.

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.