Analysis Of Flow Field Characteristics Of Submarine Launched Vehicle During Launching Out Of Cylinder

The volleying of submarine-launched vehicle is a process in which the submarine is used as the launch platform and the multiple sailing bodies are launched continuously in a very short time interval with a certain launch space interval by highpressure gas ejection.It not only has the complex flow phenomena such as the air mass oscillation at the nozzle and the "water hammer" effect involved in the conventional underwater launch,but also has the mutual disturbance of multiple vehicles and the coupling effect of flow field and motion,which is a typical dynamic fluid body interaction problem.The problem of underwater volleying has a strong engineering application background,which is a common way of modern underwater launch.In this paper,the theoretical analysis and experiments methods are used to study the development of air mass,the evolution of multiphase flow filed structure,the pressure characteristics in the launching cylinder and the mechanisation of "water hammer",analyzed the evolution and coupling of the flow field at the mouth of the two cylinders during the volleying of the submarine-launched vehicle,and obtained the influence of different launch conditions on the process of the submarine-launched vehicle.The specific research content and achievements are as follows:Time sequence controlled high-pressure ejection structure and adjustable speed device are used to design a experimental system that can realize the submarinelaunched vehicle volley at different launch time intervals,different pressures and different launch speeds.The experimental image data is collected by a high-speed camera and an underwater camera,and the test data is extracted by pressure sensor and Dong-hua data acquisition system.Based on the RANS equation,a numerical simulation method is established,the VOF method and six-degree-of-freedom model are introduced,and the overlapping grid method was used.Then the validity of the numerical method is verified by comparing the results of experiment and numerical simulation.Based on the experimental method,the process of submarine-launched vehicle launching in separate and in parallel is studied,the evolution characteristics of air mass is analyzed,the development of the air mass and its relationship with the pressure oscillation in the cylinder are obtained.The influence of the launch pressure on the evolution of the air mass and the pressure oscillation in the cylinder is analyzed,and the variation law of the air mass at the nozzle under different launching pressures is obtained.On this basis,the influence of launch pressure and launch time interval on the flow field characteristics and "water hammer" characteristics are discussed.Based on the numerical method,the characteristics of multiphase flow and launch platform pressure are researched.The evolution of flow field structure and local flow characteristics at the moment of air mass breaking are studied.The characteristics of pressure distribution and variation in cylinder and launch surface are analyzed.The law of "water hammer" effect is revealed.Then the process of submarine-launched vehicle launching in parallel is studied.The characteristics of flow evolution in the process of single and parral launching are compared and analyzed.The action law between the air mass of the first and the second cylinder is given.The characteristics of pressure distribution in cylinder and launch surface in the process of parral launching are analyzed.At last,the influence of launching sequence is studied.