What would electromobility be like in the sky to drastically reduce the emissions caused by air traffic? How can aircraft with alternative propulsion systems be ecological and economical at the same time?
- A concept for the perspective of sustainable aviation will emerge in four years.
- The focus is on propulsion concepts for short-haul aircraft with significantly reduced emissions and less noise when considering batteries, fuel cells, and hydrogen.
- Effects on the entire eco and aviation system, i.e. on airports, airlines, as well as air traffic control and the atmosphere, are examined.
- Focus: aviation, digitization, climate-friendly flying
Are such new aircraft changing the aviation system, for example, airports or maintenance halls? The German Aerospace Center (DLR) intends to provide answers to these questions within the next four years.
Since the beginning of 2020, 45 scientists from 20 DLR institutes have been working together on the EXACT project (Exploration of Electric Aircraft Concepts and Technologies) to develop new technology modules for an eco-efficient commercial aircraft.
The overarching goal is to bring the required technologies for such an aircraft with at least 70 seats and a range of 2,000 kilometers to maturity by 2040. In the first step, different hybrid-electric drive concepts and possible aircraft configurations will be examined. However, interactions with the airport infrastructure are also considered, just as new drives affect the atmosphere and thus the climate. “DLR has unique expertise in the conduct of such a complex study. Our 45-strong team combines our expertise in the different research areas. In this way we achieve both the necessary thematic breadth and the scientific depth, ”says Dr. Johannes Hartmann from the DLR Institute of System Architecture for Aviation, which is responsible for leading the project.
Digital design process
With the help of data from the entire life cycle of an aircraft, from design through production to operation and subsequent disposal, the researchers have information from which they can derive knowledge for aircraft design. The specified goals are that the emissions of the aircraft do not negatively influence the climate and at the same time, it is to be operated economically. The design process is viewed holistically and aligned with these goals. The planning of production, operation, and maintenance are included in the design from the start. In the past, aircraft were primarily cost-driven, and their climate impact was only analyzed afterward. “We are turning this process around for the first time and are therefore choosing a revolutionary approach to our work,”
Climate-neutral drive concepts
Aircraft with an improved carbon footprint requires fundamentally new propulsion technologies. The project team is investigating which drive concepts for short-haul aircraft would result in significantly reduced emissions and less noise during operation and which are compatible with the interests of the economy. Batteries, fuel cells, or hydrogen-powered aircraft offer the potential to bring these requirements into harmony.
The DLR Institute of Technical Thermodynamics has been analyzing and evaluating the performance classes of fuel cells for aviation for several years. With this in mind, fuel cells are characterized in the laboratory and examined in the four-seater Hy4 passenger aircraft. With the help of simulation models and pilot applications, the knowledge developed in the EXACT project should now evaluate the interaction of the hybrid energy concepts in a larger performance class and make them usable.
Air traffic system 2040
Novel aircraft will affect the entire current aviation system and vice versa. Dr. Kai Wicke from the DLR Institute for Maintenance and Modification examines the operational and ecological integration of the new aircraft configurations in the EXACT project: “Whether a new aircraft is powered by hydrogen, fuel cell or battery – we take a holistic view of the effects this will have on the entire eco and Aviation system would have, so at airports, airlines as well as air traffic control and atmosphere. ”
His team sets up models for climate impact, noise, and product and energy life cycles. Here, environmental impacts, as well as investment, operating and maintenance costs, are examined. If an aircraft were refueled with hydrogen, special refueling systems would be required. Batteries should be able to be charged, stored and recycled. It has to be clarified what requirements the existing infrastructure places on the operation of a new aircraft.
In four years, the first holistic concept for environmentally compatible air traffic should be ready. Aircraft engineers, atmospheric researchers, and electrical engineers from 20 different DLR institutes work together to create valid models and develop solutions.