Dynamics Of Water Entry For Deflated Cavity Shell

Deflated cavity shell is a kind of open at one end the other end closed but are frustrated hole of the cylindrical shell structure,and in the open end collision free liquid surface,low-speed vertically into the water,in the process of gas inside the cylindrical cavity condensed and released from frustrated hole,to form a gas and liquid two phase flow coupling space,and the external flow field through the open end.Flow in this complex environment,frustrated cavity shell into the phenomenon of water flow and water flow into the traditional semi-enclosed cavity solid movement of body phenomenon is different,so in frustrated cavity shell into the water multiphase flow characteristics research has important theoretical significance and practical value.This article adopts the combination of theoretical analysis,numerical calculation and experimental methods,the problem such as hydrodynamic research,the main research content is as follows:By means of high speed camera test,the flow pattern and evolution characteristics of water cavitation are studied.In this paper,an experiment was carried out for the inlet water of a shell with a deflated cavity under different inlet water velocities.The inlet water experiments of different deflator holes and asymmetric open end shells were carried out.The effects of floating weight ratio on the entry trajectory and the entry cavitation are studied.The flow mode of two-phase flow field inside the cavity was obtained and its formation mechanism was revealed.Based on computational fluid dynamics method,has conducted a frustrated cavity shell vertically into the numerical simulation of water problem,numerical calculation model is established,with reference to the experiment conditions to carry out the corresponding simulation,compared with the experimental data to verify the validity of the numerical method.Through the analysis of the results of the deflated low-speed vertical cavity shell into water cavity shape evolution characteristics,and flow field distribution of velocity field and vorticity field,the structure of the flow field within the parameters of the analysis;The open end pressure concentration and wall pressure distribution in the pressure field are described.The influence of the size of the deflator hole on cavitation shape,flow field structure and motion characteristics of the shell was analyzed.