Simulation And Test Research On Lubricating Drag Reduction Of Curved Subsoil Shovel And Solute Transfer Of Lubricating Fertilizer Solution

There have always been problems in deep loose ground preparation,such as large working resistance,serious machine wear,and high working energy consumption.These problems hinder the promotion,development and popularization of subsoil technology,and subsoil shovel,as one of the tillage tools,plays a vital role in realizing the development of conservation tillage.This paper takes the liquid lubrication drag reduction curved subsoiling shovel as the research object,constructs a CFD-DEM coupling simulation model,and simulates the watersoluble fertilizer lubrication drag reduction process and the water-soluble fertilizer solute transport process in the subsoil operation.Analyze the changes in resistance during the deep loosening process and the distribution of soil water-soluble fertilizer solutes after deep loosening,and provide theoretical support for the operation parameters of the lubricated drag reducing curved surface deep loosening shovel.The main research contents of this paper are as follows:(1)The function and working principle of the lubricated and drag-reducing curved surface deep loosening shovel are analyzed.The lubricating and drag-reducing curved subsoiling shovel can simultaneously realize the lubricating drag-reducing subsoiling and the deep application of the soil conditioner in one operation.The working principle is that the subsoiling shovel can continuously flow out the lubricating liquid through the orifice on the shovel surface during the subsoiling operation.The working principle is that the subsoil shovel forms a liquid film on the surface of the shovel body through the orifice on the shovel surface during subsoil operation to reduce the operating resistance,and realizes deep soil improvement after subsoil is completed.(2)Establish a CFD-DEM coupling simulation model.Various physical parameters of the experimental soil in Wudi County,Binzhou City were measured,including particle size distribution,water content,compactness and angle of repose.Through a combination of experiment and simulation,the best contact parameters between soil and soil and between soil and sample and subsoil shovel are determined,and a CFD-DEM coupling simulation model that can effectively characterize the lubrication and drag reduction process of subsoil shovel is established.The FLUENT-EDEM coupling simulation of the lubrication drag reduction subloosening process is repeated on the basis of relevant literature,and the key parameters such as fluid phase,discrete phase,and dynamic grid are determined.(3)Designed and built an indoor soil tank test platform.The lubrication and drag reduction tests of different flow rates were carried out through the lubrication and drag reduction test specimens,and the resistance data of the specimens in the test were compared with the coupled simulation data.In Wudi County,Binzhou City,a field deep loosening experiment with a lubrication and drag reduction curved surface deep loosening shovel was carried out.The resistance value of the test was compared with the simulated resistance value of the deep loosening to verify the feasibility of the coupled simulation model to simulate the drag reduction process of liquid lubrication.Construct a simplified model of the shovel surface of the liquidlubricated drag reduction curved subsoil shovel,analyze the disturbance of the soil under different operation modes through simulation,conduct multiple sets of coupled simulation simulation tests on the subsoil operation process under different flow rates and speeds,and pass the response surface The software analyzes the influence of the two factors of flow and speed on the resistance of deep loosening.(4)According to the demand of winter wheat for nitrogen fertilizer,water-soluble fertilizer is used as the lubricating liquid,and the subsoiling solute transport is analyzed by HYDRUS.The boundary conditions,hydraulic characteristic parameters and solute transport parameters of the HYDRUS numerical simulation were determined by subsoiling test and simulated soil disturbance analysis.Numerical simulation of the infiltration distribution of water-soluble nitrogen fertilizer solute in the subsoiling fertilization method was carried out,and the subsoiling test was carried out to verify it.Through numerical simulation,the distribution of water-soluble fertilizer solutes in the soil under different fertilization operations is simulated to determine the operation parameters of deep fertilization,so that the distribution of water-soluble fertilizer solutes meets the planting interval and nutrient requirements of winter wheat.