Numerical and experimental study on the influence of a moonpool on motion performance and stability of a drillship

The existence of a moonpool may affect motion characteristics and stability drillship. This paper presents numerical experimental study on the influence configuration performance drillship under condition constant displacement. Ship hydrostatics three-dimensional (3D) potential flow theory are employed to calculate static curves (GZ curves) response amplitude operators (RAOs) with conjoined double moonpools, separated moonpools single rectangular respectively. Numerical model is validated by sea-keeping tests carried out in towing tank. It found that there critical heeling angle for curve variation opening size merely have significant effect heave RAOs near piston mode resonance period, while slightly pitch sloshing period. demonstrated smaller or larger openings displacement can reduce dramatically roll around natural period bow quartering waves beam waves, coupling leading decreasing as well heave, observed results. results presented this provide references design