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水田作业机械的减阻研究具有重要节能意义,但因水田饱和泥土层的离散特性、力学特性等不同于旱作土壤,目前多数的模拟方法都不能直接应用到水田相关的研究中。为了研究水田作业机械仿生表面的减阻机理,并找到适用于水田饱和泥土-机具交互作用相关研究的仿真分析方法,利用离散元软件EDEM建立了水田泥土的离散颗粒模型,构建了水田机械部件表面与水田饱和泥土层相接触的力学模型,对机械触泥部件表面进行了仿鱼鳞微结构表面减阻设计,通过离散元理论,对水田饱和泥土-机具交互作用过程进行了仿真分析,获得了样件所受切向剪切力、泥水颗粒运动轨迹及不同分布规律。运用流体润滑理论和摩擦学理论对水田机械触泥部件仿生微结构表面的减阻机理进行了分析。分析结果表明:在前进速度为0.8m·s~(-1)时(高速插秧机一般前进速度),仿生平面的平均剪切应力为1.59E-05N,光滑平面的平均剪切应力为3.71E-05N,可计算出仿生样件在水田泥土条件下所受的总阻力减少49.84%。对比光滑表面样件,仿生样件具有更好的减阻效果,可以改善润滑条件,形成流体润滑效果;减少接触面积;改变摩擦系数并改变泥水运移方式。本研究可为水田作业机械的减阻研究并水田饱和泥土-机具交互作用的相关研究提供理论借鉴。
However, most of the simulation methods can not be directly applied to paddy fields because of their different dispersion and mechanical properties from paddy soils. In order to study the drag reduction mechanism of the biomimetic surface of paddy field work machinery and to find the simulation analysis method suitable for the study of the interaction between paddy soil and saturated soil-tool, the discrete particle model of paddy soil was established by the discrete element software EDEM, The mechanical model of contact with the saturated soil layer in paddy field was used to simulate the drag reduction of the mechanical mud-permeable component surface. The discrete element theory was used to simulate the interaction of saturated soil-tool interaction in paddy field. Shear shear force, mud particles movement trajectory and different distribution. The fluid-drag theory and tribology theory were used to analyze the drag reduction mechanism of bionic micro-structure surface of mud-contacting parts of paddy field. The results show that the average shear stress of the bionic plane is 1.59E-05N and the average shear stress of the smooth plane is 3.71E at the forward speed of 0.8m · s ~ (-1) (the general forward speed of the high speed transplanter) -05N, it can be calculated that the total resistance of bionic samples under paddy soil conditions decreased by 49.84%. Compared with the smooth surface sample, the bionic sample has a better drag reduction effect, which can improve the lubrication conditions, form the fluid lubrication effect, reduce the contact area, change the friction coefficient and change the migration mode of the muddy water. This study can provide theoretical reference for the research on the drag reduction of paddy farm machinery and the research on the interaction between paddy soil and saturated soil-tool.