Experimental study of the liquid damping effects on a SDOF vertical sloshing tank

The analysis of violent sloshing is of great interest for European aeroplane manufacturers. It has been widely reported that aircraft fuel sloshing significantly damps wing vibrations, but the complexity of the fluid–structure phenomena still demands further research. The aim of this work is to define an experimental methodology to quantify the sloshing force acting on a vertical Single Degree Of Freedom (SDOF) tank when the accelerations are similar to the ones found in a real wing. In this work, two different methodologies are presented for the calculation of the sloshing force involved in the SDOF tests, finding a very good level of agreement between them. A Froude scaled SDOF experiment has been devised for sloshing study, confirming first that the fluid presence increases the damping of the system notably, and second that the slosh-induced damping force is composed of an inertial term and a dissipative term. The sloshing force study also shows that this force is shifted with respect to position measurements, and this phase-shift is a key element in fluid-induced energy dissipation. A global energy study connecting the sources of energy dissipation with the forces involved in the dynamics of the system is performed, obtaining a quantitative contribution of the fluid’s role in the system. Finally, a numerical model has been tested using the experimentally obtained sloshing forces as an input exhibiting good agreement with the previously obtained experimental results