To elucidate the relationship between pipeline erosion and wear during slurry transportation,this study considers three key influencing parameters,namely,the ratio of inlet to outlet pipe diameter,the length of the va...To elucidate the relationship between pipeline erosion and wear during slurry transportation,this study considers three key influencing parameters,namely,the ratio of inlet to outlet pipe diameter,the length of the variable diameter section,and the roughness of the pipe wall.The impact of these factors on pipeline erosion and wear is analyzed using a single-factor analysis approach.In particular,the Fluent software is employed to conduct the required numerical simulations for variable diameter elbows of varying morphologies.The results indicate that as the inlet to outlet diameter ratio increases,the wear on the pipe inlet and the outer wall of the elbow becomes increasingly pronounced.Notably,when the diameter ratio exceeds 0.8,there is a significant escalation in wear on both the inner and outer elbow walls.Initially,the maximum erosion rate decreases sharply with increasing diameter ratio before a stable condition is attained.Erosion wear in the variable diameter section exhibits a distinct layered distribution pattern.In this region,the wear range for a 40 mm length of the pipe body is relatively small;however,once this length exceeds 40 mm,the wear range expands,ultimately covering the entire pipe section.The length of the variable diameter section significantly influences the maximum erosion rate of the pipeline,with sections shorter than 80 mm experiencing the most severe effects,and showing an exponential decline in erosion rate.As the wall roughness gradually increases,the wear area on both cheeks of the bend section rapidly expands and tends to deepen further.When the roughness reaches 4 mm,the pipeline wear experiences a dramatic shift,resulting in extensive“spot-like”wear patterns emerging at the bottom and sides of the horizontal flow section,which previously exhibited no wear.展开更多
The design of the loading path is one of the important research contents of the tube hydroforming process.Optimization of loading paths using optimization algorithms has received attention due to the inefficiency of o...The design of the loading path is one of the important research contents of the tube hydroforming process.Optimization of loading paths using optimization algorithms has received attention due to the inefficiency of only finite element optimization.In this paper,the hydroforming process of 5A02 aluminum alloy variable diameter tube was as the research object.Fuzzy control was used to optimize the loading path,and the fuzzy rule base was established based on FEM.The minimum wall thickness and wall thickness reduction rate were determined as input membership functions,and the axial feeds variable value of the next step was used as output membership functions.The results show that the optimized loading path greatly improves the uniformity of wall thickness and the forming effect compared with the linear loading path.The round corner lamination rate of the tube is 91.2%under the fuzzy control optimized loading path,which was increased by 47.1%and 22.6%compared with linear loading Path 1 and Path 2,respectively.Based on the optimized loading path in the experiment,the minimum wall thickness of the variable diameter tube was 1.32 mm and the maximum thinning rate was 12.4%.The experimental results were consistent with the simulation results,which verified the accuracy of fuzzy control.The research results provide a reference for improving the forming quality of thin-walled tubes and plates.展开更多
In order to further reduce the damage rate in threshing seed corn,a seed corn threshing testbed with variable diameter and spacing that can realize dynamic adjustment of parameters,such as feed quantity,rotating speed...In order to further reduce the damage rate in threshing seed corn,a seed corn threshing testbed with variable diameter and spacing that can realize dynamic adjustment of parameters,such as feed quantity,rotating speed of the threshing device,threshing spacing of the threshing units,was designed in this research.The software of finite element analysis ANSYS Workbench was applied to do modal analysis on the threshing axis designed for variable diameter and spacing of seed corn.The first 8 orders of natural frequencies were distributed in 201.12-1640.20 Hz,with corresponding vibration amplitude in 5.86-27.04 mm,showing reasonable structural design of the threshing axis,which could realize effective seed corn threshing and conveying.Discrete element method was applied to do simulation analysis on the seed corn threshing and conveying process with variable diameter and spacing.Under the condition of different feed quantity,different rotating speed of the thresher,the moving speed of corn clusters and contact force among clusters were measured through simulation,and the working characteristics of the threshing testbed for low-damage and dynamic threshing and conveying of seed corn with variable diameter and spacing were revealed.Working performance test results of the testbed of seed corn with variable diameter and spacing showed that,when the rotating speed of the threshing axis was 190-290 r/min,feed quantity was 1.80-3.80 kg/s,the damage rate of seed corn was 0.32%-0.63%,threshing rate was 99.20%-99.82%,and content impurity rate was 4.23%-5.86%,the mass of threshed corn grains first increased and then decreased along the axial direction.The test verification process was in line with the simulation results;thus,the test results could satisfy the requirements in design and actual operation.展开更多
基金supported by the project of the Educational Department of Liaoning Province(No.LJKMZ20220825)the National Natural Science Foundation of China(51774199).
文摘To elucidate the relationship between pipeline erosion and wear during slurry transportation,this study considers three key influencing parameters,namely,the ratio of inlet to outlet pipe diameter,the length of the variable diameter section,and the roughness of the pipe wall.The impact of these factors on pipeline erosion and wear is analyzed using a single-factor analysis approach.In particular,the Fluent software is employed to conduct the required numerical simulations for variable diameter elbows of varying morphologies.The results indicate that as the inlet to outlet diameter ratio increases,the wear on the pipe inlet and the outer wall of the elbow becomes increasingly pronounced.Notably,when the diameter ratio exceeds 0.8,there is a significant escalation in wear on both the inner and outer elbow walls.Initially,the maximum erosion rate decreases sharply with increasing diameter ratio before a stable condition is attained.Erosion wear in the variable diameter section exhibits a distinct layered distribution pattern.In this region,the wear range for a 40 mm length of the pipe body is relatively small;however,once this length exceeds 40 mm,the wear range expands,ultimately covering the entire pipe section.The length of the variable diameter section significantly influences the maximum erosion rate of the pipeline,with sections shorter than 80 mm experiencing the most severe effects,and showing an exponential decline in erosion rate.As the wall roughness gradually increases,the wear area on both cheeks of the bend section rapidly expands and tends to deepen further.When the roughness reaches 4 mm,the pipeline wear experiences a dramatic shift,resulting in extensive“spot-like”wear patterns emerging at the bottom and sides of the horizontal flow section,which previously exhibited no wear.
基金supported by the Shenyang Science and Technology Program(grant number 22-301-1-10).
文摘The design of the loading path is one of the important research contents of the tube hydroforming process.Optimization of loading paths using optimization algorithms has received attention due to the inefficiency of only finite element optimization.In this paper,the hydroforming process of 5A02 aluminum alloy variable diameter tube was as the research object.Fuzzy control was used to optimize the loading path,and the fuzzy rule base was established based on FEM.The minimum wall thickness and wall thickness reduction rate were determined as input membership functions,and the axial feeds variable value of the next step was used as output membership functions.The results show that the optimized loading path greatly improves the uniformity of wall thickness and the forming effect compared with the linear loading path.The round corner lamination rate of the tube is 91.2%under the fuzzy control optimized loading path,which was increased by 47.1%and 22.6%compared with linear loading Path 1 and Path 2,respectively.Based on the optimized loading path in the experiment,the minimum wall thickness of the variable diameter tube was 1.32 mm and the maximum thinning rate was 12.4%.The experimental results were consistent with the simulation results,which verified the accuracy of fuzzy control.The research results provide a reference for improving the forming quality of thin-walled tubes and plates.
基金financially supported by Key Science and Technology Project of Gansu Province(Grant No.21ZD10NF003-4-01)Department of Agriculture and Rural Areas of Gansu Province Agricultural Machinery Equipment Remediation Project(Grant No.niyf2022-02)+1 种基金Fuxi Young Talents Fund of Gansu Agricultural University(Grant No.Gaufx-03Y01)Youth Tutor Fund of Gansu Agricultural University(Grant No.GAU-QDFC-2021-08).
文摘In order to further reduce the damage rate in threshing seed corn,a seed corn threshing testbed with variable diameter and spacing that can realize dynamic adjustment of parameters,such as feed quantity,rotating speed of the threshing device,threshing spacing of the threshing units,was designed in this research.The software of finite element analysis ANSYS Workbench was applied to do modal analysis on the threshing axis designed for variable diameter and spacing of seed corn.The first 8 orders of natural frequencies were distributed in 201.12-1640.20 Hz,with corresponding vibration amplitude in 5.86-27.04 mm,showing reasonable structural design of the threshing axis,which could realize effective seed corn threshing and conveying.Discrete element method was applied to do simulation analysis on the seed corn threshing and conveying process with variable diameter and spacing.Under the condition of different feed quantity,different rotating speed of the thresher,the moving speed of corn clusters and contact force among clusters were measured through simulation,and the working characteristics of the threshing testbed for low-damage and dynamic threshing and conveying of seed corn with variable diameter and spacing were revealed.Working performance test results of the testbed of seed corn with variable diameter and spacing showed that,when the rotating speed of the threshing axis was 190-290 r/min,feed quantity was 1.80-3.80 kg/s,the damage rate of seed corn was 0.32%-0.63%,threshing rate was 99.20%-99.82%,and content impurity rate was 4.23%-5.86%,the mass of threshed corn grains first increased and then decreased along the axial direction.The test verification process was in line with the simulation results;thus,the test results could satisfy the requirements in design and actual operation.
