OMA analysis for the identification of the damping properties of a sloshing fluid

In this paper, the modal characteristics of a sloshing fluid at different operating conditions are estimated using Operational Modal Analysis (OMA) methods. The chosen system is characterized by a plexiglass tank filled with water mimicking the fuel tank inside an aircraft wing. Specifically, the considered tests are aimed at evaluating the sensitivity of the eigen-properties of the fluid to the random excitation levels and the liquid filling levels. Such experimental investigations are carried out at the environmental test facility available at the Department of Mechanical and Aerospace Engineering of the University of Rome “La Sapienza” which provided the closed-loop control vibrations at the base of the tank. Because the chosen tank system can be considered fully uncoupled with the dynamics of the sloshing fluid, these tests can be considered as a preliminary laboratory representation of the fluid sloshing inside an actual aircraft wing, thus contributing to the formation of the experimental database for the European funded project SLOshing Wing Dynamics (SLOWD).