Two-dimensional numerical study on fluid resonance in the narrow gap between two rigid-connected heave boxes in waves

This paper considers the motion response and hydrodynamic characteristics of two rigid-connected boxes freely heaving in waves. Two numerical models were established for the numerical simulation, namely an in-house Constrained Interpolation Profile (CIP) method-based code and a commercial Computational Fluid Dynamics (CFD) tool STAR-CCM+ combined with the overset mesh approach. Based on the developed numerical models, the motion response and hydrodynamic forces of the rigid-connected boxes were simulated under incident waves of different frequency. The effects of the body draft and the distance between the connected boxes were also discussed. Numerical results demonstrated that the developed two numerical models can accurately predict the motion response and hydrodynamic resonance characteristics of the rigid-connected boxes in waves. A systematic analysis proved that the hydrodynamic characteristics of the rigid-connected boxes are quite different under free heave condition and under motion constrained condition.