Study on silage mixing device of King Grass stalk particles based on DEM simulation and bench test

Abstract

This study designed a silage mixing device for King Grass stalk particles and optimized the core component, the blender, based on the discrete element method (DEM). Through simulation tests, the effect of different blender forms, blade lengths and blade orientations on the Lacey mixing index (LMI) was studied, and the structural form of the blender was selected as the inclined blade-same-up impeller blender. Based on simulation tests, to verify the reliability of the simulation test and further determine the optimal blade inclination angle and mixing speed of the blender, a mixing experimental bench was built for bench tests. The LMI was compared between simulation and bench tests. At three speeds of 60, 80 and 100 r min- −1, the average relative errors are 2.3%, 2.1% and 1.5%, indicating that the simulation test can simulate actual tests well. The central composite design (CCD) was used to establish a binary quadratic regression model of the effects of blade inclination angle and mixing speed on LMI and mixing energy consumption. Using the NSGA-II algorithm, it was determined that the best inclination angle of the mixing blade is 42° and the best mixing speed is 78 r min−1.