Study On The Movement Of Grain Particles On Bionic Non-smooth Surface In Grain Tanks

There is a problem of adhesion and accumulation during grain transport in the combine grain storage tank,which seriously affects the efficiency of harvesting machines.The movement of rice grains was numerically simulated during the unloading process from the grain tank of the combine harvester with the discrete element method(DEM)analyzed the change of grain tank pressure distribution on the walls,and studies the grain flow characteristics.A reduced size grain tank bench was designed and built.Based on the test bench,the particle flow characteristics on the surface of the materials and the operating parameters of the grain tank were studied.The particle motion in the unloading process of grain tank with different simulated non smooth surface was studied through simulation and real experiment with the test bench.This is of great importance in reducing the adhesion and accumulation and adhesion of grain on the walls of grain tank and the design,manufacture and improvement of the grain tank of the combine harvester.The movement of rice grain during grain unloading was simulated based on DEM,and the pressure distribution of grain tank was studied.The results showed that the pressure of different walls is inconsistent.When the grain tank was full of particles,the four vertical walls bear lower stress than the two inclined walls at the bottom of the grain tank,while the wall at the bottom of the grain tank bears the highest pressure.The surface material of grain tank(steel,acrylic,wood,and plastic),the inclination angle of grain tank bottom,and the rotating speed of screw auger as variables,the grain flow characteristics during grain unloading were studied through simulation and bench test.The results showed that the adhesion of rice grains on wood surface was less than that on steel and acrylic surface,while the adhesion on plastic surface was greater than that of other materials.Increased the inclination angle of the bottom of the grain tank increases the adhesion of rice grains on the surface,increased the rotating speed of the auger and reduces the adhesion of grains on the surface of the grain tank.Two different bionic non smooth surface types were applied to the surface of grain tank,and the changes of grain adhesion and movement during grain tank unloading were studied based on Simulation and real test.The results showed that the simulation of rice grain adhesion on non smooth bionic surface was similar to the results of bench test.The grain mass adhered to bionic 1and bionic 2 surfaces was less than that on smooth surfaces.Comparing the qualitative adhesion of rice grains on the two bionic surface samples,the adhesion of rice grains on bionic 1 surface is lower than that on bionic 2 surface.In this study,the data of grain tank wall pressure distribution,grain tank bottom inclination angle and surface material can be used in the design of grain tank manufacturing.The research shows that the bionic non smooth surface can be used in grain processing equipment to reduce the adhesion and accumulation of grains on wet surfaces.