Research On The Cavitation Jet Mechanism And Numerical Simulation Of Blade Type Pipeline Cleaner

With the popularization of pipeline transportation industrialization,the problem of pipeline scaling is more serious,which seriously affects the efficiency of pipeline transportation and reduces the transport capacity.Therefore,descaling is of great importance for pipeline transportation and popularization.The current physical and chemical descaling methods on pipelines have disadvantages such as high risk,shorter cleaning distance and polluted environment.The cavitation cleaning technology uses the strong impact force produced by cavitation burst to remove scale,which is an efficient pipeline cleaning technology of environment protection.The blade type cavitation cleaner is taken as the research object,and the cleaning mechanism is deeply studied.Based on the research results,a composite blade type cavitation cleaner is designed,and the experimental test system is built.The parameterized modeling method is used to simplify the flow field model of blade cavitation cleaner and to analysis the mechanism of cavitation cleaning.The blade type cavitation flow field is simplified with equivalent area method,and the flow field characteristics of bubble collapse was analysed under turbulent condition with Matlab software,the rules of bubble motion,bubble collapse pressure fluctuation,temperature and velocity of microjet flow field was obtained.Under different parametric conditions,with numerical simulation software Fluent to analyze the variation of flow field characteristics near the wall collapse,the variation of the flow field characteristics of cavitation,pressure pulsation,collapse time and the microjet velocity were obtained.At the same time,the results were compared with the results of Matlab,The results show that the turbulence phenomenon will change pressure fluctuation,temperature and jet velocity when the bubble collapse,improve the cleaning effect.A new type of the composite blade cavitation cleaner was designed.The structure of the composite blade cavitation cleaner was designed on the basis of the optimization parameters of the cavitation nozzle.Through the analysis of the flow field of the composite blade cavitation cleaner,the coupling of the flow field of the blade and the nozzle of the composite cavitation cleaner and the change rule of the cavitation region are obtained.Compared with the flow field characteristics of pure blade cavitation cleaner,the results show that the compound cavitation cleaner has better cavitation effect.The cavitation cleaning test system was set up to test the cavitation effect of the inspection area of the cleaner with the camera method and multiple pressure distribution test method.And the generation and variation of the bubble groups in the cleaner under different pressures inlet were observed.At the same time,the characteristics of pressure change at different positions of the flow field of the cleaner were obtained.