A SPH simulation of the sloshing phenomenon inside fuel tanks of the aircraft wings

The wings of large civil passenger aircrafts, which are designed to withstand the loads occurring from atmospheric gusts and turbulence to landing impacts, still demand further research. This goal will be achieved through investigating the damping effect of sloshing on the dynamics of flexible wing-like structures carrying liquid via the development of experimental set-ups complemented by numerical models. The aim of this work is to analyze the effect of sloshing in reducing the design loads on aircraft structures using SPH as the main numerical tool. The first step of this research was performed inside the Airbus Protospace Lab in Filton (UK), where a scaled model of the problem was tested. The wing is represented by a cantilever with a liquid tank attached at its tip. The behaviour of the system once deformed and released and the accelerations at the free end of the beam were registered for different configurations. In this work, a numerical model of a fully coupled fluidstructure interaction problem is developed. In order to understand and analyse the damping mechanisms, the structure is modelled through beam theory and solved by two different methods: a mass-spring-damper system and modal analysis. For the fluid, the δ-LES-SPH model is used, which has been implemented for the boundary integrals methodology in order to simulate complex geometries. A set of cases are simulated in order to reproduce trends noticed in the experiments, including different inner tank configurations, for the two beam models tested. SPH as numerical tool demonstrates that the presence of liquid in tanks attached to flexible structures introduces a damping effect