Numerical Simulation Of Torpedo Structure And Transient Flow Field During Underwater Launch

Torpedo,as one of the important weapons in naval operations in China,has always been paid attention to by military units.Among all kinds of launching technologies,the research and development of torpedo launching technology focuses more on underwater launching because of its better concealment.This topic comes from a domestic research institute,and mainly focuses on hydraulic cylinder-driven weapon launching system.However,this new launching system is still in the stage of design and development,and there are many technical problems.On the one hand,it is the structural problem of torpedo.Whether the structural strength and stiffness of torpedo shell can meet the requirements of launching and underwater combat environment when using this new launching system to launch torpedo;On the other hand,it is the safety of torpedo launching.Torpedoes launched in deep sea environment will be disturbed by seawater,and may collide with submarines,resulting in launching failure.If these technical problems are not solved scientifically,there will be serious security risks in launching,which will directly affect the success or failure of naval forces in underwater operations.These problems are urgent scientific problems to be solved.In the research and development stage,there is no condition for large-scale launch test.In order to solve the above technical problems,the research work related to torpedo structure and underwater launch flow field is carried out.The main research contents of this paper are as follows:1.The transient dynamic finite element analysis of torpedo under three launching conditions is carried out,and the stress,strain and displacement of torpedo at different times are calculated.The results are analyzed,and the strength and stiffness of torpedo shell are checked according to relevant evaluation standards and methods.The results show that the strength and stiffness of torpedo shell meet the requirements of launching and underwater combat environment under three launching conditions.2.Aiming at the underwater torpedo launching problem of hydraulic cylinder-driven launcher,the unsteady calculation model of underwater torpedo launching is established,and the transient flow field of underwater torpedo launching under the most dangerous working conditions is numerically simulated by CFD using FLUENT combined with UDF.According to the calculation results,the evolution characteristics of pressure and velocity in the flow field during launching process,the loading characteristics of the structural surface during launching process,the safety of torpedo movement in the initial stage and the safety of torpedo leaving the boat during launching process are deeply studied.The results mainly show that the torpedo can be safely launched under the most dangerous working conditions,without colliding with the submarine outlet under the interference of the flow field,and the torpedo can smoothly exit the pipe and safely leave the submarine.