Navigation Safety Analysis Of Submarine After Underwater Vehicle Launching

In recent years,there have been frequent local wars,and sea dominance has become increasingly important.It is urgent to protect the security of territorial waters and build a powerful maritime force.As an important underwater combat platform,the submarine,known as “the ghost of the sea”,has extremely high value for the research and analysis of the safety of the submarine.In this paper,through a combination of theoretical analysis and numerical simulation,a multi-angle study on the underwater launch,underwater navigation process and safety of submarine is carried out.Based on STAR CCM+,a full-scale submarine and a moving body model are selected,and a numerical simulation model for the underwater launch of a moving body is established.The calculation ability,calculation accuracy and calculation efficiency are comprehensively considered,and this problem is decomposed into the underwater launch process of the moving body and the underwater launching process of the moving body.Simulate and analyze the navigation process one by one.When simulating the underwater launch process of a moving body,the boundary conditions are established according to the research problem,the calculation results are compared with the experimental data of the literature,the accuracy of the numerical calculation model is verified,the grid independence is verified,and the appropriate parameters are determined for the moving body.When simulating the underwater navigation process of a moving body,a threedimensional global grid is selected,and boundary conditions are set up according to the research problem and the actual situation to verify the independence of the grid and the independence of the computational domain.After many simulations,the safe speed of the moving body out of the cylinder under certain conditions is obtained and verified,and the dynamic characteristics of the moving body during the sailing process are analyzed in detail.The underwater navigation process of the moving body is studied from six aspects: different ocean current direction,launch position,launch angle,submarine speed,submarine size and moving body size,and the force,moment,acceleration and speed of the moving body under different conditions.Compare and analyze the law of changes in force,and obtain the distance between the moving body and the submarine and the safety level under different launch conditions according to the submarine safety level and calculation formula stipulated in this article.Finally,an optimization scheme for launching conditions under each variable is given.The results show that the farther the launching position of the moving body is from the middle position of the submarine,the larger the radius of the submarine,the greater the mass of the moving body and the higher the safety;while the launching angle of the moving body is not linear with its safety level,the safest is when the angle is 90° and 120°;there is a threshold for boat speed,and it is best to keep it at 4to 8 knots.Finally,an optimization scheme for launching conditions under each variable is given.