Modeling of Unmanned Underwater Vehicle with Rotating Thrusters for Offshore Rig Inspection

The offshore rig preservation and inspection are critical tasks conducted to accomplish the safety standards followed by the rig contractors and operators. The underwater vehicles can help the oil companies to inspect and keep the system safe for operations and maintenances. Controllability and maneuverability of the vehicles depends on various forces including hydrodynamic forces applied on them. This paper investigates the modeling of an Unmanned Underwater Vehicle (UUV) in virtual 3D platform and conducts analysis on horizontal and vertical rotating thrusters. It also highlights the challenges involved in balancing the thrusters against the forces during execution of safety inspections. The Computational Fluid Dynamics (CFD) and Finite Element Method (FEM) were carried out in propellers to confirm the effect of forces. The structure of the full model of the thrusters was analyzed with and without nozzles. The thrust force generated by horizontal and vertical thrusters was compared to identify the optimum performance. The roles of vehicle size, weight and operating depth in the design of UUV were also considered. It was observed that UUV equipped with camera and sensor can detect any kind of oil spillage and monitor the health of the underwater structure of the offshore rigs.