Numerical Simulation of Self-Propelled Dive Motion of a Virtual Mooring Buoy

To verify the feasibility of the variable wing actuator for a virtual mooring buoy, this paper investigates the self-propelled dive motion of a virtual mooring buoy under hydrostatic variable density conditions using a computational fluid dynamics (CFD) approach. The virtual mooring buoy developed by our research group is used in this study, and the numerical simulation is performed using the Reynolds-averaged Navier–Stokes (RANS) equation and the SST K-Omega turbulence model to capture the turbulent flow. Grid convergence studies were conducted at three grid resolutions to ensure the accuracy of the numerical simulations. The effects of different wing angles on the self-propelled dive motion of the buoy are focused on and analyzed. The results show that the maximum velocity of the buoy in the horizontal direction can reach 0.31 m/s, with a wing angle of −8°, which is about 35% higher than that of 0°, effectively enhancing the buoy’s anti-disturbance capability against the horizontal currents. In addition, this study further analyzes the self-propelled dive motion of the buoy with variable wing angles. The results show that the velocity and attitude of the buoy at any moment are basically the same as those under the corresponding fixed wing angle. This shows that it is possible to change the motion of the buoy by varying the wing angle, verifying the feasibility of the variable wing actuator.