粘重土壤条件下铲式触土部件主动抗粘脱附减阻机理

Years of practical application discovery that the serious problem of soil adhesion on the spade-styling soil tillage components is appeared obviously in heavy-adhesional wetting soil region.For the purpose of solving serious problem of soil adhesion, from the viewpoint of changing hydrophobic property and its micro structure of surface on the soil tillage component,in this reseach new method of reduction of soil adhesion by coupling bionics based on biomimetic hydrophobic surface with its structures and differential geometry surface theory is proposed. The anti-adhesion hydrophobic surface and its structure as well as the material composition,etc ,of the bionic prototype were studied to explore their active anti-stick mechanism in heavy soil with high water content.The hydrophobic coating were coated on bionic specimens by mechanical alloying and cold spraying technique.Then combined with differential geometry surface theory, this project makes intensive study on coupling reducing adhesion mechanism in heavy-adhesional wetting soil region based on the bionic hydrophobic surface and its structure and the structure by differential geometry surface theory. Kinematics and dynamic models of adhesion and desorption were built to obtain the various factors and their relationship which effect the performance of reduction of soil adhesion.The main factors and appropriate parameters were identified by simulating.The structure and parameters of the bionic specimens were determined by testing. Then the typical spade-styling soil tillage components based on bionic structure and differential geometry were designed and manufactured. Thus to obtain primary and secondary factors which influenced the active anti-adhesion and desorption performance and its optimal level combination by testing, as well as to establish the regression equation of each factors affecting the anti-adhesive drag reduction performance. Also,multi-objective optimization design for the structure and operating parameters was carried on and the reliability and accuracy of optimization results were verified by experiment. This project develops theories and techniques of bionic coupling design for active anti-adhesion and desorption of spade-styling soil tillage components in heavy clay soil conditions.

针对粘重土壤中铲式触土部件由土壤粘附造成耕作阻力大的难题，项目以仿生疏水表面及其结构为切入点，结合微分几何曲面论，提出仿生疏水表面及结构与微分几何曲面论的耦合主动抗粘脱附减阻新方案。对仿生原型的疏水抗粘表面及结构、材料成分等进行研究，采用合金化和冷喷涂等技术制备具有疏水斥土涂层的仿生试件，探究其在含水率较高的粘重土壤中主动抗粘作用机理，再结合微分几何曲面论，综合探索铲式触土部件在粘重土壤下主动抗粘脱附机理，构建土壤粘附力学模型，明确影响其抗粘脱附减阻性能的各因素及其相互关系，仿真找出主要影响因素及其适宜参数范围，试验确定试件的结构方案及参数；设计制造基于仿生疏水表面结构-微分几何曲面论的典型铲式触土部件，试验确定影响其主动抗粘脱附性能的主次因素及最优水平组合，构建各因素的回归方程，综合优化结构及参数，试验验证优化结果的可靠性，形成适用粘重土壤条件的铲式触土部件主动抗粘脱附的设计理论与方法。

项目针对粘重土壤中铲式触土部件由土壤粘附造成耕作阻力大的难题，项目以仿生疏水表面及其结构为切入点，提出仿生疏水表面及结构的耦合主动抗粘脱附减阻新方案。项目以典型的铲式触土部件-马铃薯挖掘铲为研究对象，按研究计划实施并完成了相关研究内容，主要研究内容与结果有：.① 项目以白茅根为仿生原型，测试得到其表面润湿特性；从微观角度对疏水表面的抗粘机理进行了理论分析。对粘重土壤颗粒的离散元仿真参数进行了标定。试验验证并揭示了仿生结构与低表面能涂层在耕作中的减阻作用机制。 .② 依据仿生原型设计多种仿生挖掘铲，基于离散元法，通过设计相应的仿真试验方案进行仿真试验研究。通过仿真试验，初步确定了各减阻仿生铲的设计参数范围，结果表明多种仿生结构具有减阻性能。.③ 对定型的仿生纵波纹减阻结构进行优化设计，同时引入3种低表面能的涂层，以波纹结构的幅值与频率为关键设计参数，通过多梯次的多轮次土槽试验，系统研究了仿生结构在4种不同含水率土壤条件及不同表面涂层材料下的减阻性能，分析了不同含水率土壤条件下仿生结构参数及表面涂层对减阻性能的影响，最终得到了最优的仿生结构参数及仿生减阻结构适宜的参数范围。.④ 以传统平铲为参照对象，通过设计油耗对比试验及阻力对比试验，对仿生减阻挖掘铲进行田间性能验证。试验验证得到，在粘重土壤条件下，仿生挖掘铲比传统平铲具有较优的减阻性能，耕作阻力减少了10%以上，综合油耗降低了10%以上，达到预期研究目标。.⑤ 在仿真试验与物理试验的结果分析基础上，提出了从能量守恒的宏观角度，对土壤与仿生结构之间的动力学进行分析，建立了仿生减阻结构与黏土之间的力学分析模型，理论分析了在粘重土壤中仿生减阻结构的减阻机理，揭示了仿生结构与低表面能涂层在耕作中的减阻作用机制，从理论上验证了仿真试验与物理试验的结果。形成适用粘重土壤条件的铲式触土部件主动抗粘脱附的设计理论与方法。