Parameter Identification And Hydrodynamic Performance Study Of Wave Glide

Wave glider is a new type of ocean unmanned observation platform,which uses wave energy to provide forward momentum and solar energy to supply power.Because of its long range,strong load,excellent survivability and the use of environmental energy,the wave glider has been widely used in marine scientific research,commercial and military fields.However,due to the under-actuated characteristic,the wave glider dependents on wave energy,and the wave environment restricts the navigation performance of wave glider.The wave glider has a special double-body structure,so how to consider the influence of the dynamic changes of the motion attitude of the submerged glider and its hydrodynamic parameters,and how to efficiently convert the wave energy obtained by the surface float into kinetic energy at the submerged glider to improve the hydrodynamic performance of the wave glider.Aiming at the above problems,the following research work was carried out in this thesis.Firstly,the dynamic models of the float and the submerged glider of the wave glider under vertical plane were established by Newton-Euler method.The force of the pitch motion of the hydrofoils was analyzed,and the umbilical cable with tension state and slack state was analyzed.Secondly,the theoretical basis of computational fluid dynamics was briefly explained,and the simulation model used in this thesis was introduced from the aspects of mesh generation,computational domain segmentation,mesh convergence and time step independence.The translational hydrodynamic data of the submerged glider under different hydrofoil pitch angles and different incidence angles of attack were simulated and calculated by using ANSYS FLUENT software.Using the dynamic mesh technique,the vertical planar motion mechanism(VPMM)was simulated and the additional mass coefficients under three degrees of freedom of the glider were obtained.In addition,the hydrodynamic characteristics of the float were simulated and analyzed by using ANSYS AQWA software.Thirdly,the structural parameters of the submerged glider were analyzed,the dynamic models with the simulated hydrodynamic data and structural parameter data were numerically simulated.The relationships among the forward speed of the wave glider,the average pitch angle,the amplitude of pitch angle and the pitch angle standard deviation of the submerged glider and the wave height and wave period conditions were analyzed,and the corresponding conclusions were drawn.Finally,the sea trial of straight line navigation was completed,and the experimental values and simulated values under the same wave height and wave period were compared and analyzed to verify the effectiveness of the simulated hydrodynamic data and the rationality of the numerical simulation results of the dynamic model,which provides a theoretical basis and reference for the structure parameter optimization of the submerged glider in future.