The Research On Numerical Simulation About Water Entry Of3D Elastic Body

When researching into the problem of water entry, due to the structural forms, postures intothe water and structural materials are not identical, the impact loads of the structures sufferedalso are different. With the aid of ANSYS/Ls-dyna dynamic numerical simulation software,the processes of3D elastic revolver body and wedge body into the water are researched in thispaper. Different parameters on the influence of the elastic body and flow field are discussed,and the conclusions about design and optimization of structure shape, resistance and thesafety have certain reference values and guiding significances.By using ALE algorithm in Ls-dyna, the article carries on numerical simulation for theflat-bottom cylinder vertically into water experiment, finds that the pressure of cylinderbottom decreases in the radial direction, verifies the reasonableness of the model andparameters after comparing with the experiment datas, and discusses the issues related tostructure into the water, which provides the technical support for the subsequent dynamicnumerical simulation analysis. On this basis, the paper specifically researches postures intothe water and structural material of two kinds of structures: revolver body and wedge body,analyzes the postures into the water and structural materials influencing on structures andflow field in the process of bumping into water and water submerging into the water, andcompares the curves of structures’ pressure, velocity, acceleration, resistance coefficient,strain and flow field’s distribution, the spread of shock wave and changes of cavitation formunder different initial states into the water. The study finds that the elastic body oscillatessignificantly earlier, and due to initial velocity’s larger the shock pressure and waveincreases obviously. For rotor body, the changes of pressure and strain are similar, and theplanar area of head have a influence on pressure. Aluminium alloy elastic body sufferssmaller shock pressure than A3steel one. Finally, the paper uses FE/SPH method to study the problem of water entry, compares pressures and velocities calculated by FE method andFE/SPH method, and finds the pressure is smaller and velocity’ decay is faster by usingFE/SPH method.