MEASUREMENT FOR THE HYDRODYNAMIC COEFFICIENTS OF THE MODEL OF AN ULTRA-DEEP WATER WORK-CLASS ROV IN THE O-TUBE FACILITY

摘要

Remotely-operated vehicles (ROVs) play an important role in offshore engineering, marine research, submarine rescue, etc., whose hydrodynamic coefficients are significant to their manoeuvrability and stability. The measurements for the hydrodynamic coefficients of an ultra-deep water work-class ROV were conducted using the O-tube facility. The O-tube has a test section with dimensions of 1 m×1 m× 17.6 m, in which the current velocity up to 3m/s can be generated. A 1/10 ROV model was held in the centre of the cross-section via a supporting bar with diameter 25 mm. The force signals were acquired from a load cell that could sense three-dimensional forces and moments simultaneously. The measurement strategy was validated via an alternative cuboid model. The three-dimensional forces and moments were obtained subsequently with respect to the bow, stern, top, bottom, and port faces of the ROV model under two steady incoming flow velocities. The results show that the drag coefficient varies within 0.8-1.2 for different faces and the bow face design has significant influence on the drag and pitch moment coefficients when piloting forward.