Analysis Of Fluid-solid Coupling Vibration Of Several Typical Flow Pipeline Structure

As a safe,economical and efficient fluid delivery system,fluid pipeline system is widely used in many fields in modeRN industry and daily life.In the operation of the pipeline system,when the fluid passes through the pipeline,the fluid flow condition can be forcibly changed due to the changes of the pipeline structure,the pipeline diameter and the influence of the valve,which can induce the vibration of the pipeline,even leakage or other disastrous consequences in more serious circumstances.In order to improve the reliability of the pipeline system,it is necessary to study the vibration characteristics of the pipeline system,to analyze the coupling vibration mechanism between the fluid and the pipeline theoretically,and to find the vibration isolation and damping methods of the pipeline system.Based on these requirements,this paper focuses on the numerical simulation and experimental research on the fluid-solid coupling vibration characteristics of the conveying flow pipe.It analyzes the mechanism of coupling vibration and verifies the fluid-solid coupling calculation method,and provides theoretical and technical support for the engineering problems of the vibration analysis and control of the conveying pipe.In this paper,the theoretical basis of fluid-structure interaction,calculation platform and numerical method are briefly introduced first.The numerical simulation model of fluid-solid coupling of pipeline structure and the determination method of pipeline constraints are also given.A reservoir-pipe-valve-reservoir system was designed and set up to experimentally study the fluid-solid coupling vibration characteristics of pipeline system induced by conveying liquid medium in RPVR system.Corresponding to the pipeline structure of RPVR experimental system,a three-dimensional fluid-solid coupling numerical simulation of the typical pipeline structure was carried out.The results of fluid-structure interaction agree well with the experimental results,which has verified the feasibility of the three-dimensional fluid-solid coupling modeling and calculation method.To analyze the coupling vibration characteristics of typical diversion pipelines delivering gaseous medium,an experimental system of air compressor-air tank-valve-flexible conduit-flow meter(CAVFF)system was designed and set up.The fluid-structure interaction vibration induced by two kinds of shunt pipeline systems were studied.The vibration characteristics of typical CAVFF pipelines were analyzed by the modal analysis of pipelines and the numerical simulation of three-dimensional fluid-structure interaction respectively.The results show that there is a large error in the modal analysis because of its failure to consider the fluid-structure interaction between the fluid and the pipe wall,so it is only suitable for rough estimation of the natural frequency of the structure.The conditions of transporting gas is similar with transporting liquid,and the results of fluid-solid coupling of typical pipeline structure agree with the experimental results well.The fluid-solid coupling analysis of the typical pipe structure,structural modal analysis and experimental results show that fluid-solid coupling effect of the three-way,T-tube and other typical pipeline is remarkable.In the engineering application,the vibration characteristic analysis of piping system can be roughly calculated by structural modal analysis,while the fluid-solid coupling method is more suitable for the analysis of vibration characteristics and vibration mechanism of complex piping structures.