Liquid sloshing in a flexible tank subjected to a gabor wavelet type base accelerations
Résumé
Sloshing phenomenon refers to the motion of a liquid which has a free surface inside a container subjected to external perturbations. Some examples of sloshing consist of nuclear reactors, liquid storage, and transport of liquids in road vehicles or sea ships. The violent sloshing may be caused by high external excitation amplitude, or oscillations near the natural frequency of sloshing. The dangerous aspect that sloshing can present, especially in the case of resonance, makes this phenomenon a crucial matter for a good deal of research, engineering and industrial applications. Theoretical studies have led to a better understanding of the sloshing of liquids; however, they are known to be limited in the case of overturning and breaking waves in violent sloshing cases. For this reason, numerical analysis has become an important alternative approach in liquid sloshing studies, and much work has been done in the application of CFD (Computational Fluid dynamics) to liquid sloshing. In addition, the two-phase aspect of sloshing requires specific numerical techniques for the free surface tracking, which deforms under external excitations. In this work, we are interested in fixed-base storage tanks subjected to ground accelerations. Among the challenges facing storage tanks, are stability and mechanical resistance to external perturbations such as earthquakes. In order to reproduce a motion similar to that of an earthquake, the Gabor wavelet is used. A Gabor wavelet signal is a product of a harmonic oscillation and a bell-shaped function (Gaussian envelope). Having a pulse shape, the Gabor wavelet is used to simulate seismic excitations in several works, as can be found in [1]. A comparison between a rigid and a flexible tank cases subjected to a Gabor wavelet is carried out. The time evolution of the liquid oscillation for a rigid and a flexible tank cases is analyzed