MOVING GRID MODEL FOR SIMULATION OF FREE SURFACE BEHAVIOR INDUCED BY HORIZONTAL CYLINDERS EXIT AND ENTRY

Computationnal fluid dynamics (CFD) analysis is applied to investigate the two dimensional entry and exit of horizontal cylinders in calm water. Free surface interaction with the moving cylinders is modelled using the volume of fluid method (VOF) and the dynamic mesh technique (DMT) is adopted to follow the bodies motions. The developed model is validated by following series of numerical experiments conducted by the fixed grid model of Lin (2007), with a single moving horizontal cylinder in calm water moving with constant or variable velocity. The computed free surface profiles were in very good agreement with those of Lin (2007) for both cases of an immersed cylinder moving upward or downward. For the case of water impact and entry, numerical results showed that the splash jet is adequately simulated along with the associated impulsive forces and the high pressures reported by Lin (2007). Once validated, this model was applied to study the interaction between the free surface and the entry and exit of twin cylinders. Compared to the single cylinder cases, the two cylinders simulations results showed that their impacts were much more significant for the entry case where a large central jet was observed.