Sloshing and Motion Analysis of a Modular Aquaculture Tank in Rough Inshore Seas

Abstract

Floating closed containment fish farms are highly susceptible to severe sloshing due to their large proportion of internal liquid mass. The coupled fluid-structure interaction is shown to be affected by the presence of internal liquid as the rigid body motion of a closed containment fish farm is subject of sloshing analysis through CFD simulations applying external wave loads.

The simulations demonstrate how internal fluid and external wave loads influence both the global motions of the tank and the internal sloshing dynamics. While the absolute accuracy of the simulations is limited by modeling assumptions and simplifications, comparative analyses across simulation cases offer credible insights into the system’s dynamic behavior.

Three configurations are examined: a tank with internal solid mass, a tank containing internal liquid and a tank containing liquid integrated with a floater structure to resemble a complete Postsmolt platform. The latter simulation case evaluates the wave-dampening effect of the floater structure and its impact on both rigid body motion and internal sloshing dynamics.

Results show a significant increase in surge motion when internal liquid is present compared to the case with solid internal mass. In the third case, the floater structure reduces the maximum surge displacement by 43% and pitch motion by 47%, which demonstrates an effectiveness in dissipating wave loads.

The inclusion of the floater structure also demonstrates a reduction of the internal sloshing amplitude by up to 72% for measuring points.