Three-dimentional Simulation In Water Entry Of Small Scale Rotary Body

The research on the water entry has broad application value in military andcivilian, which covers, gas phase, vapor phase, liquid phase and the unsteady fluiddynamics problem briefly.It has been the focus of research in recent years. In orderto study the cavitation flow, dynamics and other correlative factors of water entry ofrevolving body, a CFD method is presented to numerically simulate the physicalprocess of revolving body entering water.Based on the basic control equation, the method to numerically simulate thephysical process of revolving body entering water is determined, including theselection of appropriate multiphase flow model, turbulent model and naturalcavitation model. The dividing method and the range of application of ICEMstructured grid and unstructured grid is studied in depth, dynamic mesh and six DOFsolver are researched, which provide the guarantee of numerically simulating thetilted water entry of revolving body of3D, six degrees of freedom.ICEM structured grid and dynamic mesh are used to simulate the physicalprocess of revolving body of the single degree of freedom vertically entering waterfreely.The development process of cavitation and the change laws of fluid dynamicsare analyzed and compared with the experimental data, which shows the simulatingmethod is validated. The influence of velocity of entering the water on cavitationmorphology and change of the pressure field is researched further.For the tilted water entry of revolving body of3D, six degrees of freedom,according to the differences of unstructured grid, hybrid grid and dynamic meshupdate, three numerical calculation methods are tried. Finally, the application ofhybrid grid and local remeshing are adopted to obtain the ideal cavity form, studythe change laws of velocity field and pressure field when cavity closure occurred onsurface and in the water, and research the influence of water entry angle oncavitation morphology and the laws of flow dynamics.