Changing demands among future passengers and developing trends in the global aviation market are resulting in the need for new, agile cabin designs and fuselage concepts. As such, aeronautics research is placing a stronger emphasis on the digitalisation of the aircraft cabin. The recently launched InDiCaD (Innovative Digital Cabin Design) project is establishing the technical foundation for creating digital links between the design and layout of cabin and fuselage concepts. At the same time, a large number of technological innovations and reconfigurable modules are being integrated into cabin concepts, with a view to enabling the agile and efficient use of the entire aircraft fuselage. These include options for using the underfloor area that was previously reserved for cargo. Ultimately, the aim is to promote reduce environmental impact and increase individual comfort. Previous DLR work on aircraft cabins, such as in the field of safety requirements, are being incorporated into the InDiCaD project.

Developing a digital chain

"InDiCaD's research approach is different to the way things are usually done in aeronautics research," says Christian Hesse of the DLR Institute of System Architectures in Aeronautics, based in Hamburg. "Until now, the entire aircraft served as the basis for the cabin design, but now we are looking at things from a different perspective. When thinking about the design, we are taking the cabin as our starting point." Concepts and designs for the passenger area of an aircraft are intended to emerge from the project and then be adapted – either entirely or in a modular fashion – to new aircraft. In the future, entire aircraft may be adapted to new cabin designs. This will be possible thanks to complete digital continuity between design and layout, whereby new designs can be flexibly adapted to future requirements using computers.

A database for cabin designs

InDiCaD will create the technological prerequisites for incorporating requirements into the cabin design concepts at an early stage in the development phase. "To this end, we are developing digital methods for fully visualising the cabin as a virtual project and assessing its potential," explains Frank Meller, Head of the Cabins and Payload Systems Department at the DLR Institute of System Architectures in Aeronautics. "One of the primary goals of the InDiCaD project is to achieve a digital information chain that runs from design to production, and all the way through to their demonstration and implementation in operation." The institutes of Aerospace Medicine, Air Transport and Airport Research, Flight Systems, Composite Structures and Adaptive Systems, Structures and Design, Materials Research and Software Methods for Product Virtualisation are combining their expertise in fields such as new materials and cabin and fuselage technology for this project. A database of various cabin designs will be available by the end of the project in 2022.

Sleeping below deck

Completely new uses may be conceivable as part of the further development of fuselage concepts. In future, airlines want to use the underfloor areas within the fuselage for cargo and the flexible transport of additional passengers. "To this end, we will be developing new design solutions over the coming years," says Hesse. "These kinds of unconventional approaches are only possible through the type of digital linking of design and layout offered by InDiCaD." The researchers involved in the project are also addressing the more advantageous distribution of passengers across two levels in the upper section of the aircraft fuselage.

Many key aspects, such as boarding, are specifically included as part of the overall design, including the turnaround time of an aircraft on the ground, which has a major bearing on its economic efficiency. For example, researchers may look at how turnaround times and passenger changes can be represented in the cabin concepts, and which options for design adaptations are associated with this. This will also take account of the passengers, for whom the boarding and disembarking times at the airport are a key factor in the way in which they assess airlines, together with cabin comfort.

Researching modified cabin acoustics for low-emission propulsion systems

InDiCaD is also concerned with new approaches for reducing cabin noise, as new engines that reduce fuel consumption and exhaust emissions may require new technological solutions for the fuselage and cabin design. The cabin acoustics of engines with extremely high bypass ratio engines or counter-rotating, open propellers, for example, have been the subject of very little research. Active and passive noise reduction methods are to be investigated as part of the project, with the aim of resolving the expected acoustic issues. These include the active control and suppression of vibration levels in the cabin structure, along with the use of innovative aerogel materials.