Table of contents:
Video: From Water Lily To Aircraft Construction
Mother nature, father engineer: The family tree of a new component that is currently being developed by the aviation group Airbus can be described so briefly. "Weight is a crucial parameter in the aerospace industry," explains Prof. Josef Rosenkranz, Vice-Rector for Studies and Teaching at Aachen University of Applied Sciences and supervisor of Peter Petzold's bachelor's thesis. The researchers are looking for geometrical design laws and construction principles (“morphologies”) that allow maximum safety and strength to be achieved with the lowest possible weight.
Giant water lily carries people up to 70 kg
In his research work, the student Petzold, together with his Airbus supervisor Oliver Seack, examined the "Victoria cruziana" from the genus of giant water lilies. He looked at this freshwater plant on the leaf - more precisely: underneath. There are ribs and ramifications, which give the lily pad an astonishing stability, and with a low weight. “A person weighing 70 kg, whose weight is evenly distributed on the sheet, can stand on a sheet for several minutes. A large sheet can carry loads of approx. 10 kg without aids for several minutes without tearing or folding, since the ribbing divides the leaf skin into many small skin areas and effectively stiffens it,”explains the 27-year-old FH graduate of the air and space technology.
Petzold analyzed the construction principle of nature and figured out whether the structure of the water lily leaf can be transferred to the construction of aircraft components. Specifically, it's about spoilers. These are the components that are attached to the wings and that are folded up when landing. They reduce the lift of the wings and at the same time increase the air resistance. So far, these spoilers have been built as honeycomb sandwiches. The new concept provides that ribs attach to the attachment point of the spoiler and then branch off to the edges. This would reduce the weight by up to 7% and the strength would remain the same. Extrapolated over the life cycle of an aircraft, up to 350 t CO 2 emissions could be avoided.
17 exciting technology projects are waiting for their successors
3D printing enables complex structures
"This is only possible because industry can rely on new production processes," explains Prof. Rosenkranz. Specifically, it is about the additive layer manufacturing process (ALM), also known as 3D printing. Metallic materials are applied in thin layers and melted by laser, which enables the production of components with such complex structures as can be found in the new spoiler. "This is an area in which the Aachen University of Applied Sciences is a leader," says Rosenkranz, referring to the research and development work by Prof. Andreas Gebhardt and his team from the Goethe Lab in the Mechanical Engineering and Mechatronics Department.
Petzold's research is not just about taking nature as an example. "I checked the mathematical laws behind the biological design principles that could be of technical benefit," says the 27-year-old. At Airbus, this approach has fallen on fertile ground: as part of its “Smarter Skies” program, the aviation group wants to build an operational sample of the spoiler by 2018 and test it in practice. (kj)