Sloshing Dynamics in Sway Excited Rectangular Scaled Tanks

Abstract

The present paper presents the sloshing oscillation behaviour and sloshing force in three different tanks of model scales of 1:86, 1:57 and 1:43. The rectangular tank is mounted on shake table, to study the scale effect of sloshing with sway excited motion. The tests are carried out for the aspect ratio (h _s/l, where h _s liquid depth and l is the length of the tank) of 0.162 5, 0.325, and 0.487 5 which represents 25%, 50% and 75% of liquid fill levels, respectively. Seventeen excitation frequencies ranging from 0.456 6 Hz to 1.975 7 Hz are considered, which covers up to the fifth sloshing mode. The sloshing oscillations occurs in the longitudinal axis when subjected to sway excitations. An experimental setup is designed and devised to measure sloshing force by the concept of ballast mass. The inertia forces are measured by load cells and sloshing oscillation time histories are measured by capacitance probes. It is found that violent sloshing is experienced for 50% filled condition irrespective of scaled tanks, excitation amplitudes and excitation frequencies. The sloshing force is maximum in 1:43 scaled tank than other scaled sloshing tanks irrespective of the excitation frequency and amplitude for 50% fill level. Based on the experimental observations and analysis of results, it is concluded that proportionate volume of water and tank size decides the severity of sloshing in the partially filled tanks.

Keywords

Rectangular scaled tanks / Sloshing dynamics / Sloshing force / Scale effects / Free surface response