| With the rapid development of national economy,people’s material demand is gradually increasing,people’s demand for logistics transportation is also higher and higher,the traditional mode of transportation has been unable to meet the needs of social development,people urgently need to find a new mode of transportation to improve the current situation,the barrel loading pipeline hydraulic transportation technology came into being.The transportation technology has the advantages of high efficiency,environmental protection,economy,energy saving,safety and so on,and has broad application and development prospects.In this paper,the Particle Image Velocimetry(PIV)is used to measure the hydraulic characteristics of the cross-section spiral flow between the double piped carriages under the conditions of different diversion vanes lengths,and the test data are analyzed with the help of relevant theories and analysis software,and the following conclusions are obtained:(1)Under the condition of different length of the diversion vanes,the law of the contour map of the axial velocity of the same section in the pipeline carriage workshop is basically the same.In section 1(3mm from the rear of the pipeline)closest to the rear of the pipeline,the axial velocity distribution is the most disordered.In section 1,the axial velocity has obvious zoning phenomenon.The axial velocity of the area corresponding to the gap between the pipeline truck and the pipe wall is large.There are three positions in this area where the axial velocity is relatively low.The three positions are 120° apart,corresponding to the installation position of the feet,near the axis of the pipeline The axial velocity is small and negative.The axial velocity distribution of section 2(39mm away from the rear of the pipeline)is close to that of section 1,but the negative value area is much smaller than that of section 1.When it comes to section 3(75mm away from the rear of the pipeline),the axial velocity is basically positive.From section 1 to section 4(111mm away from the rear of the pipeline),the axial velocity distribution becomes more uniform along the way,while that of section 5(147mm away from the rear of the pipeline)is much smaller Compared with section 4,the axial velocity distribution becomes disordered again.(2)With the increase of the length of the diversion vanes,the fluctuation of the axial velocity on the same test section is more and more big,and the change rule of the axial velocity of the characteristic points of the section is basically the same with the increase of the length of the diversion vanes,showing the wave type distribution.In the same section,the axial velocity increases first and then decreases with the increase of the radius of the measuring ring in the direction of the measuring axis.The axial velocity along the measuring ring angle is wavy.The axial velocity of 0°,120°,240° is larger,and the axial velocity of 60°,180°,300° is smaller.(3)When the radius of the measuring ring is 45 mm,the axial velocity of the measuring point decreases first and then increases.When the radius of the measuring ring is 36 mm,the axial velocity of the measuring point decreases first and then increases and then decreases.When the radius of the measuring ring is 27 mm,18mm and 9mm,the axial velocity of the measuring point increases first and then decreases.The longer the length of the diversion vanes is,the larger the change of the axial velocity along the distance is.(4)Under the condition of different length of the diversion vanes,the change rule of the circumferential velocity distribution along the test section is basically the same.From section 1(3mm from the rear of the pipeline)to section 4(111mm from the rear of the pipeline),the contour line of circumferential velocity becomes sparse along the route,the gradient of circumferential velocity change decreases along the route,the position with larger circumferential velocity moves from the gap to the center of the pipe axis,the area with negative circumferential velocity of the test section also decreases along the route,and section 5(147mm from the rear of the pipeline)is more than section 4 The distribution of circumferential velocity becomes uneven,the gradient of circumferential velocity increases,and the area with negative circumferential velocity increases.(5)With the increase of the length of the guide strip,the change gradient of the circumferential velocity of the same test section increases,and the circumferential velocity of the characteristic test points of the test section basically shows an increasing trend.With the increase of the radius of the measuring ring,the circumferential velocity of each measuring point tends to increase first and then decrease in different directions of the measuring axis.The maximum position of the circumferential velocity moves from the position near the pipe wall to the direction of the pipe axis along the way.The circumferential velocity of the cross-section survey points is distributed in a wave shape along the angle of the survey ring,and the fluctuation range of the circumferential velocity distribution in the same survey ring gradually decreases along the course.For the same measuring ring,with the increase of the length of the guide strip,the fluctuation range of the circumferential velocity increases.(6)measuring ring,the circumferential velocity of each measuring point tends to increase first and then decrease in different directions of the measuring axis.The maximum position of the circumferential velocity moves from the position near the pipe wall to the direction of the pipe axis along the way.The circumferential velocity of the cross-section survey points is distributed in a wave shape along the angle of the survey ring,and the fluctuation range of the circumferential velocity distribution in the same survey ring gradually decreases along the course.For the same measuring ring,with the increase of the length of the diversion vanes,the fluctuation range of the circumferential velocity increases.(7)Under the condition of different length of the diversion vanes,the change rule of the radial velocity of each test section along the course is basically the same.In Section 2(39mm away from the rear of the pipeline),the area with negative radial velocity accounts for a large proportion,while the area with positive radial velocity is near the pipe wall and a small part of the pipe axis.The radial velocity distribution of section 3(75mm away from the rear of the pipeline)and section 4(111mm away from the rear of the pipeline)is similar to that of section 2 in general,but the proportion of negative value area is reduced.Section 5(distance)is similar to that of section 2 in general The area with positive radial velocity occupies most of the area.The radial velocity of different measuring rings on each section presents a wavy distribution with the increase of the angle of the measuring axis.The range of the wave along the measuring ring decreases and tends to zero.(8)Under the condition of the length of each diversion vanes,the distribution of vorticity in the section of the double carriage workshop is basically the same.The vorticity in the middle part of the tube is smaller than that in the tube wall.The vorticity in the middle part of the tube rotates in the direction of the tube axis.The vorticity along the tube wall decreases gradually.The vorticity distribution of horizontal section is more uniform than that of vertical section.With the increase of the length of the diversion vanes,the average vorticity of the cross-section of the pipeline double carriage workshop shows an increasing trend.This paper enriches and perfects the theory of hydraulic conveying technology of cylinder loading pipeline,and provides a theoretical basis for the application of pipeline truck in actual production. |
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