Modeling And Simulation Of Salvage Vessel Maneuvering Motion Based On Virtools

The thesis aims to conduct vessel maneuvering motion modeling and simulation in the background of salvage vessel simulator application. Firstly, it is to establish a 3-DOF linear model in the horizontal plane and a rolling linear model in regular waves. Secondly, using the 3D interaction software Virtools realizes the models numerical calculation and simulation, then the simulation results are tested and theoretically analysed. Finally, a vessel 3D motion simulation is performed in the Virtools virtual environment.In the case of establishing the 3-DOF linear model,the integrated modeling method is taken by using Taylor formula for a linear model, which considers the fluid power on the vessel hull, propeller and rudder as a whole.It is simple to consider the mutual interference effect in the hydrodynamic coefficients by this way.In the case of establishing the rolling linear model, the stress analysis of vessel is finished and the rolling linear model is built based on the regular waves and small rolling angle hypothesis. In calculating the parameters of the model, irregular wave theory is used to handle the actual waves in regular method.Using Virtools SDK and four-order Runge-Kutta method, the model is numerically solved, and the motion simulation is realized. On the 3-DOF linear model verification.the author compares the result of the 3-DOF linear model simulation with experimental data. It shows that the precision of 3-DOF linear model is enough for slight motion prediction and simulation.A rolling motion analysis on the vessel called "South Sea rescued 111" is finished. After the author’s working on the theoretical calculation and analysis of rolling-performance parameters, a simulation is provided. And it shows that the analysis and the results of simulation are consistent.Based on the above two numerically solved models, a 3D dynamic simulation of the "South Sea rescued 111" is achieved in the Virtools virtual environment.