Time-Domain Simulation of Barge Capsizing by a Chimera Domain Decomposition Approach

摘要

A Reynolds-Averaged Navier-Stokes (RANS) numerical method has been employed in conjunction with a chimera domain decomposition approach for time-domain simulation of capsizing behavior of a pontoon barge under large amplitude waves. Calculations were performed first for a fixed rectangular barge in beam sea conditions. The computed wave elevations, velocity vectors, and vorticity contours were compared with the corresponding experimental data obtained from Particle Image Velocimetry (PIV) measurements to verify the accuracy of the simulation results. After successful validations for the fixed barge, the method was generalized for time-domain simulations of barge capsizing in regular waves. To facilitate the simulation of large amplitude barge heave and roll motions, a general chimera domain decomposition approach was developed to handle partial hull submergence and green water on the barge deck. The barge responses were close to harmonic before the green water passed over the barge deck. Once the deck is partially submerged, however, the green water greatly impeded the barge from rolling back to its equilibrium position. This leads to a sudden change in the phase angle between the incident wave and the barge roll response. The present simulation results also indicated a drastic change of vortex structures and flow separation patterns when the deck is partially submerged.