Environment
Environmental issues have been linked continually with aviation development, primarily in relation to the noise and local pollution impacts of aircraft. More recently however, climate change has moved rapidly up the political agenda, and as a result, drawn attention to some of the more long-term environmental impacts of the aviation sector, particularly in relation to the various exhaust emissions. Research indicates that if these emissions remain unchecked, and other sectors respond successfully to climate change targets, then aviation will likely make a much more dominant contribution to climate change emissions. Aircraft exhaust emissions contribute to climate warming though emissions of CO2 from the combustion of kerosene. In addition, the altitude at which aircraft fly means that they cause additional impacts unique to this sector. These emissions and impacts can be summarised as follows:
- The altitude that the emissions are released at means that water vapour is released directly into the stratosphere where it causes warming.
- The nitrogen oxides released at altitude cause ozone formation in the upper troposphere which leads to warming. They also deplete methane causing cooling.
- Water vapour and soot released into the troposphere leads to the formation of contrails, which in turn cause additional warming
- Sulphur oxides, sulphuric acid and soot lead to an increase in the cirrus cloud cover, again further increasing the climate impact of the aircraft. However, sulphur oxides and sulphuric acid also have a direct radiative cooling effect in the troposphere.
A number of schools within the University contribute to a better understanding of the impacts of the various exhaust emissions, measures to reduce fuel burn through aerodynamic and engine design, as well as the socio-economic and climate change implications of a growing aviation industry. Some of these research areas are summarised below.
School of Mechanical Aerospace and Civil Engineering (MACE)
Aerospace engineering
The School of MACE has world-class expertise in aerodynamics and aircraft flight mechanics. Research within the school has developed a flight performance code that, among other things, is capable of providing:
- Detailed fuel consumption over specified missions and fuel breakdown, depending on aircraft and flight procedures.
- Full simulation of engine performance, with output and analysis of dozens of parameters.
- Landing and Take-off (LTO) emission cycles (HC, CO, NOx, CO2, soot) as a function of most aircraft, engine and operational parameters.
- Full aircraft noise analysis at take-off and landing, with noise trajectories at FAR points both in conventional flight and continuous ILS descent procedures.
- Optimisation procedures for flight conditions, to minimise fuel consumption (CO2 emissions), acoustic signature at reference points, cruise performance (altitude, cruise Mach number), contingency fuel depending on alternative airport scenarios, etc.
- The aircraft is fully defined by over 120 parameters and about 250 bitmap points. The airplane state is given at any time by at least a dozen performance parameters.
Aero-related turbulent flows
MACE’s expertise in turbulent flows impacts aerospace research in a number of ways. Current research includes Complex Fluid Dynamical modelling of aero-related turbulent flows, in particular: advanced models for complex separated/swirling flows; accurate and efficient near-wall modelling; unsteady flow modelling; fluid-structure interaction modelling. Recent applications include computation of wing-tip vortex development, synthetic jet simulation and unsteady separation from high incidence aerofoil. In another area of research, investigations are underway to better understand how to improve the thermal efficiency of turbine blades within aero-engines.
Combustion
With the possibility of alternative lower-carbon fuels on the horizon, research is required to better understand the combustion processes within aero-engines. Facilities in Manchester currently allow experimental investigation in the following areas: combustion instability, alternative fuels for industrial gas turbines, terahertz investigation of sooty flame at high pressure, combustion and flow diagnostics and impinging flames.
Tyndall Centre Manchester in MACE & Manchester Business School
Aviation policy studies
As an interdisciplinary research centre concerned with climate change, Tyndall’s research in aviation spans both science and social science disciplines. An investigation into the current high levels of growth within the EU’s aviation industries in the context of a decarbonising society drew attention to aviation as a growing contributor to climate change. Through scenario analysis, stakeholder engagement and policy evaluation, Tyndall continues to explore the role of aviation emissions within future climate change regimes, and, by conducting whole-system energy analysis, investigates how aviation’s energy consumption and emissions compare with those in other sectors.
The construction of demand for aviation
Drawing on Polanyian theories of instituted economic processes and complexity, interactions between the various actors within the aviation system, from manufacturers and airlines through to air traffic control, airports and consumers can be explored. In relation to consumers in particular, practice theory is used to provide a better understanding of individual and group drivers leading to high growth within the aviation industry. The relevance of demand elasticity, importance of airport locality and ideas behind trophy tourism are just some of the areas currently providing insights into the construction of demand for aviation.
Socio-economic aviation studies
The economic importance of airports and national aviation industries is often taken for granted, but given this new era of climate change-related damages and mitigation costs, the socio-economic benefits of airport expansion requires investigation. Issues relating to apportioning emissions from the aviation sector to regions within the UK in order that regional development agencies can better plan their climate change strategies have also become important. As such, work funded by the North West’s Joule Centre, based in MACE, is conducting a socio-economic assessment of the region’s airports. Employment, inward and outward investment, the flow of tourism money into and out of the region, and issues surrounding development and emission apportionment are being explored through collaboration within researchers within MACE and MBS.
School of Chemical Engineering and Analytical Science
Carbon-neutral flying using renewable energy
As part of it’s research portfolio on sustainability in chemical processing, research is being undertaken on the re-synthesis of jet fuel (kerosene) from sequestrated CO2 . Coal-fired power plants can be run in oxy-fuel mode (using pure oxygen instead of air for combustion) to produce a pure CO2 stream which because of its purity becomes a useful chemical resource. This clean pure CO2 can be reacted with hydrogen to produce jet fuel as well as other transport fuels like petrol and diesel. Renewable electricity from offshore wind is available to electrolyse water to produce the hydrogen. The by-product oxygen from this electrolysis is available “free”, making the co-process oxy-fuelling inexpensive.
Re-use of CO2 from power generation is better than underground long-term sequestration. Conventional aircraft can thus fly net carbon-neutral, with the additional benefit that the power plants are rendered zero-emission. The re-synthesised jet fuel is cleaner than that sourced conventionally from crude oil. This approach means that new generation aircraft, like the Airbus Super-jumbo 380 and the Boeing 787 Dreamliner, can fly carbon-neutral for the whole of their anticipated 50 year life. Current results show that this approach will become competitive as the cost of wind generated electricity goes below 2p per kWh. Plans are being formulated to build a pilot-scale demonstration unit in conjunction with power companies and renewable energy suppliers.
Centre for Atmospheric Science
Aerosol cloud interactions: Cloud microphysical measurements
Aircraft contribute to climate change through the emission of water vapour, soot and sulphur compounds forming contrails and cirrus clouds. Understanding the how these clouds are formed and their radiative properties is therefore essential. At SEAES, there are a number of important facilities for carrying out experimental work. For example, an AIDA Large Cloud Chamber, Airbourne Cloud Particle Imager and a BAeS 146 FAAM Research Aircraft.
Environment facilities in Manchester
The Facility for Airborne Atmospheric Measurement (FAAM) is a new NERC NCAS facility. Full details of the facility and specifications of the aircraft can be found on the FAAM web pages.
Academic Members
| Name | Research Areas |
|---|---|
| Dr K Anderson | Energy and Climate Change |
| Dr M Bleda | Environmental Economics |
| Dr A Bows | Energy and Climate Change |
| Professor T Choularton | Atmospheric Sciences |
| Dr P Bonello | Dynamics and Aeroelasticity |
| Dr A Filippone | Aerospace Engineering |
| Dr M Gallagher | Atmospheric Sciences |
| Dr S Mander | Energy and Climate Change |
| Professor R Mann | Chemical Engineering and Analytical Science |
| Dr S Randles | Instituted Economic Process |
| Dr P T Mativenga | Sustainable manufacturing |
| Professor P N Sharrat | Chemical Engineering and Analytical Scienc |
| Dr P Upham | Energy and Climate Change |
| Professor G Vaughan | Atmospheric Science |
