The maneuverability analysis of the wave glider with a propeller-rudder system

The wave glider (WG) is an ocean observation platform that utilizes wave energy drive and solar energy power supply. The propeller of the WG with a propeller-rudder system partly compensates maneuverability limitation of the WG with single-rudder or single-propeller. To accurately analyze the maneuverability of the WG, the influence of oblique flow on the propeller is considered. Computational Fluid Dynamics (CFD) method is used to calculate the hydrodynamic coefficients of the propeller, and the fitting formula for the thrust coefficient is obtained using the least squares method. To improve the accuracy of the dynamic model, the torsional force of the umbilical cable is considered and an eight degree-of-freedom (DOF) dynamic model of the WG with a propeller-rudder system is established. Numerical simulations are conducted to compare the forward speed and turning performance of the WG with the propeller-rudder system under different sea conditions, and the accuracy of the dynamic model is verified through sea trial. Results show that compared to the inactivated propeller, the mean forward speed of the WG can increase by a maximum of 3.5 times, and the average turning diameter can be reduced by 2.52 times under different sea conditions.