Research And Protection On The Propagation Law Of Shockwave Load In Submarine Pipeline

As a special kind of pipeline system on ships,the sea-going pipeline system is very important to the vitality of ships,especially submersibles.Because it is not only connected to internal equipment,but also connected to external waters,its impact load is different from general piping systems.Studying the impact load of sea piping systems will help to understand the damage mechanism for them Carried out protection design.At present,domestic and foreign researchers mainly focus on the impact load transmitted from the hull structure to the pipeline when studying the impact load of the pipeline system,and there is little research on the impact load that is transmitted by the external fluid along the sea port into the pipeline.For this reason,this paper studies the shock wave load that propagates into the pipeline from the external fluid along the Tonghaikou,and proposes anti-shock protection measures for the pipeline system.The details are as follows:Firstly,the relevant theories of shock wave propagation in water,the theory of shock wave propagation in pipelines and the simulation principle of acoustic-structure coupling method are briefly introduced,and the accuracy of acoustic-structure coupling method for simulating underwater explosion shock wave propagation is verified.Laid the foundation for the research in the following chapters.Secondly,the approximate solution formula for cylindrical shell wall pressure is derived,and the theoretical formula and numerical simulation are used to calculate the wall pressure distribution of rigid cylindrical shell.In addition,the shock wave propagation law in three typical pipe structures of straight pipes,elbow pipes and tee pipes in rigid pipes with open cylindrical shells is studied.In straight pipes,the shock wave load distribution law at the nozzle and inside the pipe when the shock wave is incident and obliquely incident is studied;in the bend pipe,the shock wave propagation law at the elbow is studied,and the bending radius of the bend pipe is analyzed.The impact of the shock wave load at the elbow;in the three-way pipe,the propagation law of the shock wave when incident from different nozzles and the change of the pressure peak in each branch pipe with the pipe diameter are studied.Thirdly,the shock wave propagation law inside the three typical pipe structures of straight pipe,elbow pipe and tee pipe in the elastoplastic pipe with a perforated cylindrical shell is studied,and the propagation law in the elastoplastic pipe is compared with the rigidity.The pipelines were compared to provide a basis for the anti-impact protection of the submersible pipeline to the sea.Finally,on the basis of the predecessors,a protection plan for installing bypass pipes in the sea-connecting pipeline system was proposed,and its protection effect was studied.In addition,a simplified shock resistance test model was proposed and corresponding Argument.