Short-Medium-Range Turboprop-Powered Aircraft as a Cost-Efficient Enabler for Low Climate Impact
Georgi Atanasov, Jennifer Wehrspohn, Markus Kühlen, Yannic Cabac, Daniel Silberhorn, Michael Kotzem, Katrin Dahlmann, Florian Linke
Abstract
View Video Presentation: https://doi.org/10.2514/6.2023-3368.vid The paper provides an insight into some of the latest findings of EXACT (Exploration of Electric Aircraft Concepts and Technologies), an internal German Aerospace Center (DLR) project. The main goal of the project is to create a roadmap of sustainable aviation concepts by comparing hybrid-electric configurations with conventional aircraft in terms of environmental impact and fleet operating costs. The results produced in EXACT so far indicate that a conventional turboprop could be a cost-efficient low-risk solution for achieving low climate impact in the short-medium-range aircraft class. At the cost of 10–15% lower cruise speed, a turboprop aircraft is around 20–30% more fuel-efficient than a turbofan of the same class and technology level. Furthermore, due to the slower cruise, a turboprop flies at significantly lower altitudes, which considerably reduces the non-CO2 impact on the environment, e.g., due to NOx emissions and contrail formation. The main disadvantage of the reduced speed is the increase in speed-related operating costs. The fleet-level assessment of the overall aircraft results shows that the fuel efficiency advantage outweighs the time-related penalties, especially considering the projections of rising fuel costs due to increased utilization of synthetic air fuels (SAF) or the implementation of carbon fees. A turboprop design offers 4–8% direct operating cost reduction for price projections of 100% SAF operation. These results imply that turboprop propulsion could potentially play an increasingly important role in the efforts of achieving an environmentally sustainable air transport system.