Characteristics of the Suppression of Sloshing in a Vessel by a Bulkhead

Abstract

This paper investigates the characteristics of the suppression of sloshing in a vessel by a bulkhead that divides the vessel vertically into two sections but allows communication between two sections at the lower part of the vessel. The sloshing behavior is thus separated into a U-tube sloshing mode and a sloshing mode confined to each of the separated compartments. The effect of the aperture height beneath the bulkhead and the amplitude of the excitation on the characteristics of the suppression of the U-tube sloshing mode is investigated experimentally. As a result, the following phenomena are clarified. Three types of flow patterns were observed: flow pattern A, with unsteady vortices, flow pattern B, with a single swirl and a vortex, and flow pattern C, with twin swirls. The flow pattern changes from A to B or C as the amplitude of the excitation increases. The damping ratio with the bulkhead is much larger than that without the bulkhead. The damping generated by the bulkhead depends on the amplitude of the excitation. The flow pattern plays an important role in the dissipation of the energy of the sloshing. In particular, the vortices and swirls increase the rate of energy dissipation of the sloshing.