Fast Aircraft Load Calculations

Air transportation is becoming more accessible to a greater number of people who can afford to travel by air. The air transportation sector forecasts that passenger and freight traffic will increase at an average rate of 4-5% per annum over the next two decades, leading to a doubling of the aircraft fleet by 2034 with respect to 2015. Formidable progress has been made since the introduction of jet-propelled aircraft about 65 years ago, but much of this improvement is offset by the huge increase in air traffic today. The Advisory Council for Aviation Research and Innovation in Europe (ACARE) "FlightPath 2050" calls for reductions of 75% in fuel burn, 65% in perceived noise, and 90% in oxides of nitrogen emissions by 2050 compared to the year 2000. NASA has proposed similar goals in the US for the "N+2" (service-entry 2025) and "N+3" (service-entry 2030-2035) generations of aircraft. These environmental constraints have generated a large effort to reduce the aerodynamic drag and to generate more efficient engines. A small reduction in fuel burn multiplied by the total number of transport aircraft leads to a significant reduction of emissions into the atmosphere.

The FALCon project will develop new methods and tools to design a new generation of transport aircraft that take advantage of wing flexibility to improve the global aircraft efficiency. The project is specifically developed around a long-standing industrial challenge: assessing the impact of aerodynamic changes on the structural loads used for structural sizing of aircraft components is an expensive process (from several weeks when low-order methods are employed, to several months when employing higher-fidelity methods). Generally, the computing cost of an aeroelastic analysis is largely dominated by the aerodynamic analysis. The novelty of the FALCon project lies in the development of a computationally-efficient aerodynamic solver that reduces the computational time by, at least, 80% compared to current state-of-the-art methods.

The FALCon project will contribute to:

- Improved realism of predictions earlier in the aircraft design process, reducing the risk of not meeting customers' expectations and shortening the time to bring new aircraft on the market.

- Reduce current conservatism in aircraft design by performing dynamic (time-domain) aeroelastic analysis, which are today neglected because of the computational costs.

- Implement a paradigm change in aircraft design through the development of enhanced design tools for conceptual and preliminary phases, including aero-servo-elastic design constraints from the start of the design process. A new design paradigm is proposed, shifting the structural deformability from a performance limitation to a design opportunity.

- A close collaboration with industry guarantees that the outcomes of the project will feed back to the UK and European aviation sector, strengthening its competitiveness. A seamless integration within the existing industrial design process is expected, adding no complications to current procedures.

The proposed research programme is expected to enable and facilitate a wide range of new technologies, many of which are likely to have a major future impact in a number of spheres beyond academia.

1) Society. The impact here is through: a) contributing toward environmental sustainability and protection; and b) improving the quality of life, health, and well-being.

Commercial aviation is one of the fastest growing sources of greenhouse gas emissions and yet a critical component of the global economic infrastructure. In addition to current growth of CO2 emissions, that will easily outstrip any gains made by improved technology, more than 30 million people will also be exposed to serious aircraft noise by 2025. The need for next-generation aircraft is readily evident from the cumulative impact of the current global fleet. Building upon the work carried out in the FALCon project, the global aircraft efficiency will be increased through the reduction in drag and in structural weight by means of enhanced design procedures. A further enhancement can be expected by increasing the load control capability using morphing devices, such as those based on a trailing edge adaptive camber mechanism. Although the project is not focused on developing morphing technologies, the aircraft configurations and the adopted tools will be able to include and quantify the gain in load alleviation due to the morphing capabilities. The expected benefits can be quantified as a reduction in aircraft drag greater than 8% together with a reduction of the structural weight greater than 10%. This combination will provide a reduction in fuel burn and pollutant emissions of at least 20% using today's engines.

2) Economy. The impact here is through enhancing the efficiency and performance of businesses, contributing toward wealth creation and economic prosperity.

Innovation in industrial aircraft design is hindered by the lack of adequate methodologies to be employed in the development of new design concepts and technologies. Hence, there is an immense potential for new methodologies, overcoming limitations of current methods and enhancing physical insights, to be integrated within an industrial environment. Any improvements, in particular, in the areas of aeroelastics and loads can lead to: a) reduction in structural weight compared to today's reference aircraft; b) reduction in induced drag, hence a reduction in fuel burn; and c) reduction in flight tests for assessing the flight control laws, hence a reduction in the time to bring new aircraft on the market.

The PI will continue to work closely with the Project Partner (Airbus Operations Ltd) to transfer and implement new methods within an industrial environment. A demonstration on current aircraft configuration will be carried out to highlight expected improvements. These actions will foster global economic performance, in particular, the economic competitiveness of the UK, and increase the effectiveness of the aerospace sector (see Letter of Support from Airbus Operations Ltd).

3) Knowledge. The impact here is through: a) enhancing the research capacity, knowledge and skills of businesses and organisations; and b) training of skilled people for non-academic professions.

Throughout the duration of the FALCon project, the PI will be engaged with the Project Partner to conduct a review of the industrial aircraft design process, as well as to facilitate the transfer of research methods to industry. During this phase, the PI will train a number of qualified engineers to use effectively the new methodologies, and explore potential ways to enhance the current design loop. In addition to this, the wider community of the CEASIOM software will benefit from improved methods (see Letter of Support from CFSE).