Research On Floating Methods And Motion Law Of The Submarine With Rudder Jammed Downward

With the development of modem society and the resources and energy on the surface being increasingly scarce,the ocean,which is rich in resources has attracted the attention of all countries in the world.Therefore,the 21st century is called the century of the ocean.As an important part of the maritime military force,the submarine is an extremely important deterrent force of the modem navy.It plays an important role both in the present and in the future maritime war.The rudder is an important malfunction of the submarine and it is one of the three basic emergency operations of the submarine.The emergency upswing of a submarine generally refers to a submarine that sails underwater.When encountering a malfunction or being attacked and unable to maintain the original navigational state,it actively discharges all or some of the seawater in the main ballast tank,which in turn makes the submarine do vertical motion to the surface of the sea.This process is likely to have large heel and trim,which is very dangerous,so it is necessary to analyze the emergency upswing in order to get possible dangerous situations in advance and take corresponding measures to reduce some losses.The submarine emergency floating motion belongs to the three-dimensional rigid body nonlinear strong maneuvering motion in the six-degree-of-freedom space.Considering the above situations,the purpose of this research is to obtain the motion law of the emergency floating up after the submarine rudder got stuck downward.The numerical prediction method of the submarine’s emergency floating after the submarine rudder got stuck downward is given and its effectiveness is verified,finally the law of motion is given,which provides a reference for the emergency floating process of the submarine.In order to ensure the safety of the submarine during the emergency floating process,it is necessary and valuable in engineering to accurately predict the motion characteristics of the submarine during the floating process.The specific research contents are as follows:Firstly,the submarine model of six-degree-of-freedom space motion in the emergency floating process is established.In the light of characteristics of the emergency floating motion problem of the submerged body,the underwater emergency floating test of the submerged body under different working conditions was designed and completed.The data of the test was analyzed.Secondly,according to the characteristics of the emergency floating motion problem of the submerged body,a set of applicable numerical calculation methods are developed,including the control equation based on RANS,the free surface processing technique based on fluid volume fimction method(VOF),Semi-implicit method for solving pressure-coupled equations(SIMPLE),the SST k-w turbulence model,the overlapping grid technique,the division of the computational domain grid,the setting of boundary conditions and so on.The selected numerical calculation method was applied to numerically simulate the emergency uplifting movement of the submerged body.The numerical simulation results are analyzed and the numerieal results are compared with the pool test results.The feasibility of the numerical calculation theory of the emergency uplift is verified.Finally,the validated numerical calculation method is applied to numerically predict the movement of the emergency uplift process of the submerged body under more working conditions,and the relevant laws are given.The effects of different factors on the hydrodynamic performance of the emergency uplift process of the submerged body are analyzed.The law of the emergency floating process when rudder of the submarine gets stuck downward is given,and the emergency floating method that the submarine can refer to is given.