Physical model experimental study on the motion responses of a multi-module aquaculture platform

A series of physical model experiments were performed to investigate the characteristics of the motion responses of a multi-module aquaculture platform. A decay test in calm water and regular wave experiments were performed for the platform in a wave basin. The natural period, damping coefficients of the platform, horizontal stiffness of the mooring system in calm water, and motion responses of the platform modules in regular waves were obtained. Owing to the central enclosed cabin and greater mass, the living module of the platform has a larger natural period and damping coefficient than the aquaculture module. Furthermore, the existence of the nets has a significant effect on the motion characteristics of the modules, and the influence of the nets on the damping of the heave motion is larger than that of the pitch motion. The motion responses of the entire platform system in the surge (sway) and yaw directions exhibit obvious low-frequency characteristics. Under regular waves with two incident angles (45° and 180°), the three-degree-of-freedom motion responses of the two types of modules exhibit the same trend as the wave frequency increases. The surge and heave responses have low-frequency characteristics, whereas the pitch response exhibits wave–frequency characteristics.