Sloshing & Slamming

The accelerations and loads induced by internal sloshing motions on global seagoing vessels such as LNG carriers are an important factor in safety design of such vessels. Ships can experience significant internal forcing due to such wave sloshing dynamics, where cargo tanks may experience additional loads on their containment system and supporting structures. FLOW-3D‘s non-inertial reference frame model allows complex motion parameters to be prescribed in order to accurately track fluid motion in a container. FLOW-3D accurately predicts liquid cargo and propellant motion in fuel tanks.

Slamming analysis as well as “green water” (water covering the deck as a result of wave spray or hull over-topping) is a common application of FLOW-3D where FLOW-3D‘s TruVOF approach to these problems provides unique capabilities for engineers in the maritime engineering industry.

This simulation shows the complex, fully-coupled motion of an LNG tanker moving in waves, as captured by FLOW-3D. The sloshing of fluid in the tanks affects the dynamics of the vessel, which contains bilge keels and a bulbous bow to help it maintain stability in incident waves. Notice also that the fluid sloshing in the tanks has a phase shift from the motion of the ship, as expected. The moving object model, the density evaluation model and the wave generation boundary conditions in FLOW-3D can assist maritime engineers in analyzing similar problems.