Experimental and numerical study of the sloshing motion in a rectangular tank with a perforated screen

Rectangular tanks partially filled with water and fitted with vertical perforated screens have been proposed as Tuned Liquid Dampers to mitigate the vibratory response of land buildings, under wind or earthquake excitation. Similar devices are used as anti-rolling tanks aboard ships. Experiments are performed on a rectangular tank with one screen at mid length. The tank is subjected to forced horizontal and rolling motions, harmonic and irregular. The open-area ratio of the screen is kept constant while the motion amplitudes and frequencies are varied. The frequency range covers the first three natural sloshing modes of the clean tank (without screen). Force measurements are converted into matrices of added mass/inertia and damping coefficients. A simple numerical model is proposed, based on linearized potential flow theory and quadratic discharge equation at the screen, following earlier works by the first author. Good agreement is reported between experimental and numerical hydrodynamic coefficients.