Experimental Study On Flow Characteristics Of Confluence Perforated Pipe Along The Pipeline

Object: perforated pipe is a device which is used to collect and distribute fluid,and widely used in various industries.The hydraulic characteristics of the perforated pipe along the confluence are related to factors such as pipe length,pipe diameter,opening spacing,opening diameter and water depth.Because there is a functioning water head above the confluence pipe,the result of the porous outflow cannot be simply added to the confluence.How to analyze the influence of various factors on the hydraulic characteristics of porous fluid distribution pipes,use theoretical knowledge to explain and test indoor laboratory phenomena and give quantitative expressions,provide a basis for engineering design,operation and supervision,and promote the development of variable mass flow theory necessary.Methods: In this paper,the pressure data,flow velocity data and flow rate data of perforated pipes with different structures and sizes under different water depth were monitored through laboratory tests.The influence of the distribution;the numerical simulation technology was used to monitor the flow velocity distribution in the pipe and the flow velocity distribution law was analyzed;through the basic principles of fluid mechanics,momentum equations,energy equations and other mathematical knowledge,the flow rate and pressure distribution of the confluent porous fluid distribution pipe were established.mathematical model.Results:(1)In the case of a certain number of perforations,the number of perforations has little effect on the flow of the manifold of the porous fluid distribution.The flow of the manifold of the porous fluid distribution increases with the increase of the pipe length,increases linearly with the increase of the acting head,increases with the increase of the pipe diameter in the case of saturated flow,and decreases with the increase of the opening spacing,when the pipe length is less than 4 When the length of the pipe is more than 4 m,the flow will not increase and reach the limit value.(2)The pressure of the perforated pipe decreases along the flow path,and the decreasing speed is faster and faster,especially the pressure in the last 1/3 section of the pipe decreases rapidly.The pressure of the perforated pipe increases with the increase of the water depth,which is basically in a linear relationship;the larger the opening distance,the smaller the pressure and the smaller the pressure drop along the way.The velocity distribution index has a linear relationship with the number of perforations,and a functional expression of the velocity distribution is obtained.(3)When the inflow and the thickness of the filter layer are fixed,the flow rate of the perforated pipe increases with the increase of the water depth;when the inflow flow and the water depth must be the same,the permeability coefficient of the in-situ sandstone is less than the artificial filter layer At the minimum permeability coefficient,the flow volume of the porous fluid distribution manifold decreases with the increase of the thickness of the original sand and gravel material,and the trend is getting slower and slower.The manifold flow of the perforated pipe increases with the increase of the total permeability coefficient of the system.When the permeability coefficients on both sides of the interface differ greatly,the outflow of perforated pipe decreases.Conclusion: The calculated value obtained from the calculation formula of the perforated pipe along the confluence and the pressure distribution formula established in the article is close to the measured value,and all the maximum error are less than 10%.The calculation formula can be used in actual engineering.