What will the aircraft of the future look like? Researchers at the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) are trying to answer this question. One possible option is known as a Blended Wing Body (BWB), an aircraft whose fuselage merges with the aerofoil section of its wings. These aircraft will be lighter, use less fuel and provide more space for passengers. For the first time, DLR researchers have generated computer-based designs for both the fuselage and cabin, establishing a theoretical basis for an enhanced and integrated aircraft design.
Theoretical design calculations - including, for example, aerodynamics and aeroelasticity – are essential for every innovation in aviation. Computer simulations allow the design team to approximately determine how the 'real' aircraft will behave, reducing development costs. "With a Blended Wing Body, we could reduce fuel consumption by around 20 percent and the operating costs by roughly 30 percent – all this while increasing engine power by up to 43 percent," says project leader Volker Gollnick, Head of the DLR Institute of Air Transportation Systems in Hamburg. The advantages of this aircraft lie primarily in its aerodynamic design. Since almost the entire aircraft is an aerofoil, lift is improved, the engines have less work to do and it is easier to construct. "Because a Blended Wing Body has no empennage or tail assembly, it must be stabilised by means of special aerodynamic techniques and flight control systems; the geometry and profile are designed so that the aircraft will be stable in flight – with the help of the control systems," explains Gollnick.
Björn Nagel and Pier Davide Ciampa's team at the DLR Institute of Air Transportation Systems has been developing preliminary designs for possible BWB configurations since 2009. Now, for the first time, they have brought together the cabin and fuselage designs, as well as the aerodynamic configuration, for this early development phase. Previous research focused on just one of the two parts, albeit at a more detailed level. "The next step will be to optimise the aircraft and integrate the required subsystems into the model: air conditioning, hydraulics and control surfaces – all this will be addressed next," says Gollnick. "It's about finding out how to make simple models of these unconventional configurations in the early design phases to provide good input for further development. In other words, we want to know, beyond the classic aerodynamic design, which functions and parameters of the structure, engines and aircraft systems – including the cabin – we need to map out early on, in order to make persuasive arguments in favour of this aircraft concept as a whole during the initial design phases. I believe the aircraft design must be further developed from a classic aerodynamic design to a functional aeroplane design, incorporating the electronic systems, cabin functions and so forth from the very beginning. These elements already make up 30 percent of the value of an aircraft and must therefore be dealt with early on."
Research institutes across the various DLR locations have been involved in national and international research on the topic of 'wing-only aircraft' for more than 10 years. Together with research partners and industry, numerous advances have been made in the different specialist disciplines and in understanding the overall system; realistic assessments of these configurations can now be made.
DLR researchers have recently completed successful tests on the flight characteristics of such a configuration as part of an in-flight simulation campaign conducted using the ATTAS (Advanced Technologies Testing Aircraft System) aircraft, which is based at Braunschweig.