Understanding how modern airliner wings respond to dynamic loads when carrying fuel
The wings of large passenger aircraft are highly flexible structures that can significantly deform when, for example, the plane encounters atmospheric turbulence or gusts. Most aircraft wings also house the fuel tanks and generally carry an amount of fuel comparable in weight to that of their structural components. Standard engineering practices for wing design do not consider the effect fuel movement, or sloshing, has on an aircraft’s design loads – in this case, the maximum amount of deformation a wing is designed to handle. “This, in large part, is due to a lack of maturity in the toolsets currently available to the industry,” says Francesco Gambioli, an expert on loads and aeroelastics at Airbus. With the support of the EU-funded SLOWD project, Gambioli is coordinating an industry-wide effort to investigate the use of fuel slosh as a means of reducing the design loads on aircraft structures. The project focused its research on the wings of large civil passenger aircraft, which are designed to withstand loads occurring from atmospheric gusts and turbulence, as well as landing impacts.
Experimental set-ups and innovative numerical and analytical tools
The primary goal of the project was to quantify the extent to which liquid sloshing in aircraft tanks affects the structural dynamic behaviour of an airliner. To achieve this goal, researchers developed experimental set-ups complemented by innovative numerical and analytical tools. “The fact that this research topic hadn’t been addressed in the past was a big challenge, but the combination of skills and expertise of the consortium members was quite incredible,” adds Gambioli. “It led to the novel application of well-established methods as well as to the development of radically new techniques for understanding and modelling the complex physical behaviour of sloshing in aircraft wings.”
Better understanding dynamic wing behaviour
Amongst those applications and methods were state-of-the-art numerical techniques that aided the design of the experimental campaign. These methods were further used to construct a sophisticated digital twin of the wing set-up. The project also developed and evaluated various reduced-order and analytical models for simplifying intricate numerical frameworks, many of which can be seamlessly integrated into a holistic design framework. “These tools allowed us to explore dynamic wing behaviour and uncover how modern airliner wings respond to dynamic loads when carrying fuel,” explains Gambioli.
Available for application in actual aircraft design
The outcomes of this research include a comprehensive database of measurements, which serves as a benchmark for the project’s numerical and analytical methods. The project also produced more than 100 articles, many of which have been published in prestigious peer-reviewed journals. According to Gambioli, the quantity and quality of the research speaks for itself. “Our work is not limited to academia but, thanks to the engagement of the project’s industrial partners, is available for application in actual aircraft design,” he concludes. The project team is currently preparing to launch a full-scale test of its solutions using a prototype wing structure.
Keywords
SLOWD, airliner, wings, fuel, fuel slosh, sloshing, aircraft, aircraft wings, aircraft design, design loads, Airbus, digital twin
