A DEM Analysis on Drag Reduction Characteristics of Paddy Field Machinery Surface with Bionic Microarchitectures
WU Li-yan;QI Sheng;SONG Yu-qiu;XIN Ming-jin;LIU Cui-hong;KONG Ai-ju;JIAO Zhi-bin;LIU Feng;REN Wen-tao;College of Engineering, Shenyang Agricultural University;
Research on drag reduction of farm machinery in paddy field has important energy conservation significance, but due to the discrete characteristics and mechanical characteristics of saturated soil layer in paddy soil are different from dry soil, the majority of simulation method cannot be directly applied to the study in paddy fields. In order to study drag reduction characteristics of paddy field machinery surface with bionic microarchitectures and find an analysis method suitable for the research in paddy field saturated soil-machine interaction, we established the discrete element model of paddy soil with EDEM and the interaction between the surface of machine parts and saturated soil layer, designed the surface of machine parts contacting with soil leaning the scales microarchitectures of Ctenopharyngodon idellus, and presented a simulation of the interaction between the surface of machine parts and the saturated soil layer. The tangential force of the two surfaces, soil particles migration and the distribution of the particles were obtained. We analyzed the drag reduction mechanism of the machine parts with bionic microstructures that contacted with soil through the theory of tribology and fluid lubrication. The simulation results showed that in the speed of 0.8m·s~(-1)(the average speed of high-speed transplanter), the average shear stress in the bionic plane was 1.59E-05 N, the average shear stress in the smooth plane was 3.71E-05 N, the bionic sample could reduce the total resistance by up to 49.84% under the condition of paddy field. The results showed that the bionic sample piece had a better drag reduction effect than the smooth sample piece, which could improve the lubrication conditions, form fluid lubrication effect, reduce the contact area and change the coefficient of friction and the way of the mud migration. This paper provided areference for the research on mechanism of drag reduction of farm machinery riding on paddy field and the research on the interaction between the surface of machine parts and saturated soil layer.