Characteristics of hydrodynamic resonance in a narrow gap between two heaving boxes

Abstract

To make a gap resonance problem closer to real engineering situations, in this study, the traditional double box fixed into two boxes going into free heave motion is changed. A water tank experiment was performed to study the influence of heave freedom on the double-box resonance, and a numerical wave tank was established based on the overset mesh technology through STAR-CCM+. The motion of two heaving boxes with different incident wave frequencies and the characteristics of the hydrodynamic resonance in a narrow gap between the two boxes were investigated based on the established numerical wave tank. The results show that the numerical model and experimental model used in the present study can accurately predict the resonance of the double-box heave motion under different incident wave frequencies and reflect the motion response and hydrodynamic resonance characteristics of the two boxes. Compared with the fixed boxes, changes happen to the resonance region of two heaving boxes, with the resonance frequency increasing and resonance amplitude decreasing. Hence, by taking the heave freedom of the two boxes into account, the gap resonance becomes much closer to that in reality, which has a positive significance to the design of marine engineering structures with a similar type of motion response.