Dynamic Characteristics Of Typical Ship Pipeline System Based On Fluid-Effect

The pipeline system is an important part of the ship power system and a channel for mass and energy transmission.The vibration and noise of pipeline system will affect the stealth and comfort of the ship,and it has been one of the hotspots of research.In order to reduce the volume of the power plant,the layouts of pipeline system is very compact,and the sharp bending is one of the most typical layouts,which leads to large changes in the pipeline flow field and is easy to cause vibration.The vibration of pipeline belongs to fluid-solid coupling dynamic problem.The influence of fluid-solid coupling effect on structural characteristics should be considered when analyzing pipeline vibration.Based on the above reasons,this paper studies the dynamic characteristics of the typical ship pipeline system considering the fluid-solid coupling effect,aiming to explore the influence of the elbow on the flow field excitation in the ship pipeline and the dynamic characteristics of the pipeline system to provide theoretical support for the design and optimization of the ship pipeline system.The main work of this paper is as follows:(1)Study on flow field excitation characteristics of centrifugal pump.Study the hydraulic,performance impeller force and pressure pulsation of centrifugal pump with computational fluid dynamics method.The results show that the flow field excitation characteristics of centrifugal pump will change with the change of boundary conditions,which lays a theoretical foundation for the study of the influence of outlet elbow on the flow field excitation of centrifugal pump.(2)Study on the influence of elbow on flow field excitation characteristics of centrifugal pump.Study on the hydraulic performance,internal flow and pressure pulsation of the model pump under different layouts of elbow with computational fluid dynamics(CFD),and the influence of different elbows on the flow field excitation of the model pump was analyzed.It was found that the flow field excitation in the centrifugal pump changed significantly with the change of layout.Therefore,the influence of pipeline on the flow field excitation of pipeline system should be taken into account.(3)Study on dynamic characteristics of pipeline system considering fluid-solid coupling effect.Through modal analysis and fluid-solid coupling form analysis,the dynamic analysis model considering the influence of elbow and fluid-solid coupling effect is established,and the dynamic characteristics of pipeline system are studied by using this model.The research shows that under the influence of fluid-solid coupling effect,the flow field excitation of pipeline is significantly enhanced,and the simulation results of vibration acceleration are in good agreement with the measured results,which verifies the accuracy of the calculation model established in this paper.(4)Pipeline system structure optimization design.Considering the support position,support quantity and connection mode of pipeline system,three optimization schemes are proposed.The research shows that increasing the number of pipeline support and adding rubber damping pipe at the pump outlet have obvious damping effect on the pipeline system.The pipeline system studied in this paper can achieve 7 d B damping effect.Through the research of this paper,a dynamic model of typical ship pipeline system considering pump source excitation and pipeline coupling is established,which can be used to analyze the vibration response characteristics of complex pipeline systems including elastic connectors and bending channels,and provide theoretical support for the design and optimization of ship pipeline systems.