A Study on the Steering Angle Optimization Considering Thruster Interaction in a Semi-submersible

摘要

Mobile offshore drilling units (MODU), such as semi-submersibles,usually employ multiple azimuth thrusters to maintain their positionduring drilling or exploration. However it is reported that there is aconsiderable degradation compared with its open water performance.This reduction results from thruster interactions with the hull, currentand other thrusts. Because it is essential for an accurate evaluation ofthe dynamic positioning capabilities (DP), researches have beenperformed to understand and quantify the thruster interaction itself.However these thrusters are often used as a self-propulsion device. Inthat case, thruster interaction affects the overall power, so the transitspeed would be decreased. In the present study, method to improve aneffective thrust during the transit operation by steering individualthruster considering the interaction was studied.