Modeling And Simulation Of Azimuth Stern Drive Tug For Shiphandling Simulator

Tug plays an important role in assisting other ship. Azimuth stern drive tug has become favorable. Azimuth tug’s maneuver ability needs deeper exploration. Full-mission shiphandling simulator need incorporate interactive tug model to improve the personnel training and engineering. This thesis focuses on ship horizontal motion mathematical model, and the main contributions of this thesis are summarized as follows.(1) This thesis builds equations of azimuth tug’s horizontal motion based on separated theory. The simulation result of mathematical model can be used to measure maneuvering performance. This thesis discusses the standard maneuver in deepwater, and divides hydrodynamic force into inertia force and viscous force. Because azimuth tugs have two azimuth propellers, this thesis should take into account resultant force when calculating thrust.(2) This thesis calculates residual resistance and ducted propeller’s thrust for azimuth stern drive tug. residual resistance is based on Target’s charts. The prismatic coefficient is an important parameter to determine residual resistance. In this thesis, reasonable value of prismatic coefficient is obtained by SHIPPOWER. By using MATLAB and interpolation method, this thesis converts resistance curve into polynomial that can be used to computer simulation. Azimuth stern drive tug’s maneuver ability largely depends on azimuth propeller system. This thesis discusses the propulsion performance of ducted propeller, and proposes a method for calculating thrust. This thesis also analyses the implication of wake and trust deduction.(3) The simulation platform is established via Visual C++6.0for testing the model’s accuracy. This thesis carries out typical tests, including spiral test, zigzag test and turning test. The model is satisfactory and reasonable in comparison with simulation results and data bought from Danish Maritime Institute.