The Simulation Of Gas-liquid Mixed Flow Impact Based On Lagrangian Particle Model

With the development of urbanization in our country,the problem of waterlogging is more and more serious during urban heavy rains.In order to solve the problem of waterlogging in urban areas,the construction and perfection of urban underground drainage system is paid more and more attention.In addition,for making full use of the rainwater resources and solving the supply problem of urban water,establishing an urban water storage system has become even more important.However,due to the instability of fluid flow,the drainage system mentioned becomes very difficult to implement.Therefore,in order to design and build the perfect drainage system,it is of great value to study the different flow conditions of the fluid in the pipeline system and which influence on the pipeline system.In order to study the fluid flow in the pipeline,especially the gas-liquid mixing and the impact to the pipeline,we introduced the Lagrangian mathematical model of the pipeline fluid during the movement,and introduced the governing equations that can describe the fluid flow state and boundary conditions.Then,the Smoothed Particle Hydrodynamics(SPH)and its modified algorithms are introduced,and the algorithms are deduced in detail.According to the SPH method,the fluid governing equations can be discretized,and then the numerical precision of SPH method and its modified algorithms is analyzed.Finally,the gas-liquid mixing and the impact problem is decomposed into five sub-problems,which are respectively solved with Lagrange modeling.The results are verified and analyzed.Through the experimental research and analysis in this paper,the availability of the meshless particle method based on the Lagrangian model in solving the pipeline fluid are verified,and the foundation of the study on the gas-liquid mixing and impact in the pipeline is also established,and it provides a theoretical basis for building the pipeline system.