Reinvigorating regional aviation through alternative propulsion concepts
The European Union is invested in achieving a European transport system that is resource-efficient, climate- and environmentally friendly, safe and seamless for the benefit of all. In the case of aviation, these goals are supported by the European Commission’s Flightpath 2050, which sets forward ambitious targets, including fuel burn reduction and 90 % of travellers within Europe completing their journey door to door within four hours, amongst other key targets. Working towards these targets is the EU-funded ELICA project. “We set out to provide a concept design of a 19 passenger commuter aircraft with near-zero emissions in terms of CO2, nitrogen oxides (NOX) and noise,” explains Qinyin Zhang, project coordinator. It was important for the concept to be environmentally friendly, i.e. with measurable reduction in estimated emission values, and economically feasible. For instance, the aircraft requirements should be derived from the market demands. It also had to be technologically innovative, i.e. the flexibility in the aircraft design space provided by new propulsion technologies should be explored and exploited.
New aircraft concept design
The ELICA project started with an economic study on the future Regional Air Mobility (RAM) market. “The study showed that the dense network of airfields in Europe and the United States can enable scheduled or on demand RAM and thin-haul air cargo services,” says Zhang. Based on the subsequent business case analysis, the top-level aircraft requirements for a future zero-emission commuter aircraft were derived. Furthermore, an extensive technology survey in the project identified the technological building blocks that will contribute to an innovative aircraft design. “For the implementation of new technologies, efficient and innovative methodologies were developed, verified and integrated into the existing aircraft design tool chain. Based on the expected technological maturity, two aircraft concept designs were developed,” reports Zhang. For 2025, combining existing mature technologies such as gas turbines, high energy-density batteries and electric motors will enable the utilisation of aero-propulsive advantages on aircraft design. “A reduction of 50 % for CO2 and NOX and 37 % less noise emission can be expected. For 2035, due to the forecasted availability of hydrogen infrastructure and high-temperature fuel cell technology, elimination of CO2 and NOX emissions, as well as 73 % noise reduction, are expected for the fuel cell powered commuter aircraft,” says Zhang.
Ambitious emission reduction goals
The ELICA project results showed that the ambitious emission reduction goals of the European Commission formulated in the Flightpath 2050 document can be achieved. “That is if the politics and the industry are willing to take determined actions,” adds Zhang. The ELICA project results also indicated that the most promising technology to achieve zero emissions for future subregional aviation would be the usage of hydrogen as fuel and the utilisation of the associated energy conversion (fuel cell) and storage technologies. “By sharing all the findings with the public, ELICA project results will help start-ups (e.g. ZeroAvia, H2FLY) and established aerospace companies (e.g. Airbus, Rolls-Royce) who are already active in introducing hydrogen into aviation and accelerate the aircraft development process, and finally contribute to emission-free future aviation,” concludes Zhang. The final concept design will help the aeronautical industry to define the next R&D steps and pave the way for innovative flying aircraft demonstrators.
Keywords
ELICA, aviation, commuter aircraft, hydrogen, fuel cells, aeronautical industry, propulsion technologies, near-zero emissions, noise reduction, Regional Air Mobility
