In the quest to decarbonize aviation, a groundbreaking study led by Gabriele Sirtori from the Department of Aerospace Science and Technology at Politecnico di Milano is paving the way for innovative aircraft propulsion technologies. Published in the journal Aerospace, the research, part of the European Commission’s Clean Sky 2 initiative, explores how hydrogen and electric propulsion can revolutionize the aviation industry, from small general aviation planes to long-range airliners.
The study, titled “Innovative Aircraft Propulsive Configurations: Technology Evaluation and Operations in the SIENA Project,” delves into the scalability of hybrid-electric concepts for next-generation aircraft. Sirtori and his team have been working on identifying and accelerating the development of propulsion technologies that can be scaled across five aircraft categories. Their findings suggest that hydrogen could be the key energy source for the future of aviation.
“Hydrogen can be efficiently used by fuel cells for propulsive and system power for smaller aircraft, typically driven by propellers,” Sirtori explains. “For short- to long-range jet aircraft, direct combustion of hydrogen combined with a fuel cell to power the on-board subsystems appears favorable.”
The research evaluates various propulsive architectures, considering components such as batteries, fuel cells, electric motors, and jet engines. The goal is to find feasible aircraft architectures that meet certification constraints and deliver the required performance. The study assesses the impact of key technology performance indicators on aircraft performance, highlighting technology switching points and the potential for scaling up technologies from smaller to larger aircraft.
One of the significant challenges identified in the study is the lack of applicable regulations for these innovative architectures. The research assesses the level of maturity in current regulations for the different technologies and aircraft categories, providing insights into the regulatory gaps that need to be addressed.
The study’s findings have implications for the energy sector, particularly in the development of hydrogen production and distribution infrastructure. As the aviation industry moves towards hydrogen-based propulsion, there will be a growing demand for hydrogen as an energy source. This shift could open up new opportunities for energy companies to invest in hydrogen production technologies and infrastructure.
Moreover, the research highlights the need for a family of system architectures consisting of hydrogen combustion gas turbines, hydrogen fuel cells, and batteries. Supporting systems, such as electric power management and thermal management, will also be crucial for the successful implementation of these technologies.
The study’s results are based on two different temporal scenarios, 2030 and 2050, and are assessed using Payload-Range Energy Efficiency as the key performance indicator. The research suggests that hydrogen-burning gas turbines are a promising option for larger aircraft, while fuel-cell-electric systems are preferred for smaller aircraft.
As the aviation industry continues to strive for net-zero emissions, the findings of this study could shape the future of aircraft propulsion technologies. The research provides a comprehensive analysis of the impact of key technology performance indicators on aircraft performance, highlighting the potential for scaling up technologies across different aircraft categories. The study’s insights into the regulatory gaps and the need for a family of system architectures could guide the development of new propulsion technologies and the necessary infrastructure to support them.
In the words of Sirtori, “The integration of hydrogen radically changes the aircraft architecture, affecting the performance as well. However, the selected family of system architectures shows the potential to decrease the mission energy demand of commercial aircraft if certain technology advancements are achieved.”
As the aviation industry looks towards a more sustainable future, the research led by Sirtori and his team at Politecnico di Milano could play a pivotal role in shaping the development of innovative aircraft propulsion technologies. The study’s findings provide valuable insights into the potential of hydrogen and electric propulsion, paving the way for a more sustainable and efficient aviation industry.
