ABSTRACT Wave impact tests were performed in the flume tank of Ecole Centrale Marseille in order to investigate whether bubble curtains could be a relevant solution as an anti-sloshing device on board membrane LNG carriers for low and partial filling conditions, when associated to a sloshing monitoring system. Bubble curtains were generated by bubblers located at the foot of the instrumented wall. Parameters related to the wave generation (focalization or solitons) and to the bubblers (type, location and gas flow rate) were screened in order to measure their influence on the impact pressures. The range of gas flow rates studied was restricted to an economically feasible range at full scale. Whatever the wave generation, the current induced by the bubble curtains favors the overturning of the wave crests and, therefore, accelerates the wave breaking process. The location of the bubblers and the gas flow rate make this process more or less efficient. The variability of the loads is increased and the size of the high loaded areas is reduced. The added compressibility of the aerated water does not seem to be of significant influence. Depending on the advancement of the wave breaking process for an incident wave, the influence of a bubble curtain on the wave impact loads turns out to be either positive or negative. Consequently, bubble curtains are not considered as a relevant principle for designing an anti-sloshing device on board LNG carriers.
INTRODUCTION Wave impact tests were performed in the wave channel of Ecole Centrale Marseille (ECM) in 2009, at two different scales (see Kimmoun et al., 2010), in order to study the scaling effects on impact pressures. During this campaign, a preparatory work consisted in enabling the generation of deterministic inflow conditions for the wave impacts at both scales.