A coupled analysis of sloshing in floating structures by integrating moving particle semi-implicit (MPS) method with a time domain multibody dynamic analysis software

Sloshing effects inside partially filled tanks on LNG carriers and FPSOs motions cannot be ignored. It is necessary to analyze the floating structures motion with the sloshing behavior simultaneously to obtain more accurate stability predictions because the phenomenon may affect the safety and the operability of the vessels in seaways and during loading and offloading process. In the present study, in order to model the coupled effects of platforms motion in waves and the liquid sloshing inside its tank, a hybrid timedomain simulation approach based on the integration of two simulators is proposed. The Numerical Offshore Tank (TPN) simulator, which is a time domain multibody dynamic analysis software, is used for the simulation of open domain hydrodynamic forces. It is able to perform calculations of coupled floating structures motion with the dynamic of mooring and connection lines and risers considering environmental condition such as wave, current and wind. In the other hand, due to the highly nonlinear aspect of the sloshing phenomenon, the Moving Particle Semi-implicit (MPS) method, which demands huge computing resources and it is more suitable to confined domain problems, is used to simulate the sloshing motion and to calculate the loads on the tank walls. The effects due to sloshing is then feed-backed to the TPN simulator as additional force and moment to solve the motion equation of the floating structure. The calculation can be distributed in a PCs cluster and each sloshing tank is solved in a different node. In this way, it allows the calculation of many tanks without increasing the computational time. Simulations were carried out with and without considering the coupled sloshing motions, and the results were compared to assess the effects of the liquid cargo sloshing on the motion of the floating structure

A coupled analysis of sloshing in floating structures by integrating moving particle semi-implicit (MPS) method with a time domain multibody dynamic analysis software

Sloshing effects inside partially filled tanks on LNG carriers and FPSOs motions cannot be ignored. It is necessary to analyze the floating structures motion with the sloshing behavior simultaneously to obtain more accurate stability predictions because the phenomenon may affect the safety and the operability of the vessels in seaways and during loading and offloading process. In the present study, in order to model the coupled effects of platforms motion in waves and the liquid sloshing inside its tank, a hybrid timedomain simulation approach based on the integration of two simulators is proposed. The Numerical Offshore Tank (TPN) simulator, which is a time domain multibody dynamic analysis software, is used for the simulation of open domain hydrodynamic forces. It is able to perform calculations of coupled floating structures motion with the dynamic of mooring and connection lines and risers considering environmental condition such as wave, current and wind. In the other hand, due to the highly nonlinear aspect of the sloshing phenomenon, the Moving Particle Semi-implicit (MPS) method, which demands huge computing resources and it is more suitable to confined domain problems, is used to simulate the sloshing motion and to calculate the loads on the tank walls. The effects due to sloshing is then feed-backed to the TPN simulator as additional force and moment to solve the motion equation of the floating structure. The calculation can be distributed in a PCs cluster and each sloshing tank is solved in a different node. In this way, it allows the calculation of many tanks without increasing the computational time. Simulations were carried out with and without considering the coupled sloshing motions, and the results were compared to assess the effects of the liquid cargo sloshing on the motion of the floating structure