Research On Maneuverability And Motion Simulation Of Multifunction Vehicle

Maneuverability is not only an important part of integral performance of Autonomous Underwater Vehicle (AUV) but also the crucial criterion of AUV design quality. The motion model of AUV can be built up, the motion simulation of AUV can be realized and the maneuverability can be forecasted if the hydrodynamic coefficients of the AUV can be obtained, and it can pave the way for the intelligent control. Therefore, calculating the hydrodynamic coefficients becomes the focus of the analysis of maneuverability performance.Three kinds of methods can be applied to obtain the hydrodynamics, namely, Hess-Smith method based on potential flow theory, semi-theoretical and semi-practical method and the restricted model experiment method. Recently, great development has been achieved in computational fluid dynamics(CFD) and in the numerical computation of turbulent flows. Meanwhile the calculating speed has been greatly improved by parallel computing technics.In this thesis, User Defined Function (UDF) and the parallel technique of commercial software FLUENT are described. And hydrodynamic coefficients of the Multifunction vehicle are got by simulating hydrodynamic experiment using FLUENT and its great dynamic mesh technique. Firstly, hydrodynamic coefficients of a standard ellipsoid model were calculated by that way and the results proved that fairly accurate results can be attained by simulating PMM test using software FLUENT.And then, the hydrodynamic coefficients of the Multifunction Vehicle of a more complex outline are calculated by simulating the resistance experiment, oblique navigation experiment and PMM experiment and compared with the results made by panel method and approximate calculation. Some nonlinear coefficients can be evaluated based on the linear coefficients.At last, the maneuverability of the Multifunction Vehicle can be forecasted by the simulation results. The simulation platform is constructed based on Visual C++. The simulation results of the vehicle's motion ability on the zigzag movement, the turning movement and the vertical movement are figured out. And that's conducive to the vehicle's primary design and its latter control system design.