黏重黑土条件下马铃薯挖掘铲仿生减阻特性分析与试验

    Analysis and experiment of the bionic drag reduction characteristics of potato digging shovels on clayey black soil conditions

    • 摘要: 针对黏重黑土地区马铃薯挖掘铲挖掘阻力大、能耗高等问题,以白茅根膜质叶鞘为仿生原型,设计了一种基于仿生波纹结构的马铃薯减阻挖掘铲。基于离散元(DEM)法仿真和土槽试验,确定减阻性能最优的设计参数;通过田间试验以油耗和阻力为指标验证仿生挖掘铲的减阻效果和挖掘性能。离散元仿真得到仿生挖掘铲最佳布置方式为纵向布置;在相同纵向布置方式下,通过土槽试验得到仿生挖掘铲的波纹参数在幅值为2.5 mm、频率为0.5时表现出较为优异的减阻性能。根据最佳参数研制仿生纵波纹铲,进行普通平铲和仿生纵波纹铲的作业对比试验,结果表明仿生纵波纹铲阻力减少了14.45%,单位油耗减少了17.15%。研究表明仿生纵波纹铲具有较好的减阻特性,仿生结构设计合理,能实现黏重黑土条件下马铃薯收获挖掘作业,可为整机节能减耗的研究奠定基础。

       

      Abstract: Digging resistance can dominate the energy consumption of potato-digging shovels in clayey black soil areas. In this study, a drag-reducing potato-digging shovel was designed using a bionic ripple structure. Among them, the rhizoma imperatae membranous sheath was taken as a bionic prototype. The optimal parameters were also determined for the drag reduction performance using the discrete element method (DEM) and soil trench test. The drag reduction and digging performance of the bionic digging shovel were then verified by the field test with the indexes of fuel consumption per unit time and drag force. The longitudinal arrangement was optimized for the better performance of the bionic digging shovel. Specifically, the optimal parameters of the bionic digging were A=2.5 mm, ω=0.5 in the soil trench test. The results show that the ripple shovel (y=2.5cos(0.5x)) achieved excellent properties of drag reduction at the soil moisture content under the condition of 35%, where the ordinary flat shovel drag reduction rate increased by 12.69%. In the soil moisture content of 65%, the spraying coating viscosity ripple shovel (y=2.5cos(0.5x)) still showed excellent properties of drag reduction, whereas the drag reduction rate of ordinary flat shovel increased by 18.27%. A comparison test was carried out between the ordinary flat and the bionic longitudinal ripple shovel. The drag-reduction rate of the bionic longitudinal corrugated shovel increased by 14.45%, and the fuel consumption rate was reduced by 17.15%. Bionic shovels presented better accumulation in the soil on the surface of the shovel rather than that in the shovel in the process of the mining operation. The bionic structure reduced the contact area and time between the soil on the surface of the shovel. The bionic shovel was performed on the short stagnation of the clod time under driving force in the same circumstances. The mining operation time of the shovel body was reduced to realize the energy-saving drag reduction in the same trip. The surface tension of the soil was also reduced using a bionic shovel surface with a low surface energy coating. The adhesion force of soil per unit area greatly contributed to the shovel of soil adhesion. There was a great decrease in the static friction coefficient between the shovel and the soil plane. Soil retention or accumulation was reduced for the soil conditions of movement and space on the surface of the shovel. Therefore, the bionic longitudinal ripple shovel performed better drag reduction, indicating the reasonable design of the bionic structure. The bionic structure of soil touching parts is of great significance in the application of potato harvesting and digging operations under clay and heavy black soil. The findings can lay a sound foundation for the energy saving and consumption reduction of the whole machine.

       

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