Parameter Combination Optimization of the Lateral Straw Clearing and Throwing Knife Based on Discrete Element Simulation

Abstract

In order to explore the laws of corn straw lateral moving and throwing, it is necessary to identify the main factors that restrict improvements in the quality of straw clearing and reductions in power consumption and then optimize the knife parameter combinations; in this paper, the kinematic analysis of single-stage lateral moving and throwing of corn straw was carried out, and the mathematical model for the collision process between the knife and straw is established. Key factors affecting the lateral moving and throwing efficiency of straw were determined according to the model analysis. A parameter combination optimization test was conducted with three-factor and five-level quadratic regression orthogonal rotation center combination test methods and discrete element virtual simulation, taking into account the edge angle of cutting, the rotation radius of the knife, and the rotation speed of the knife roller as test factors and the straw clearing rate and power consumption as performance evaluation indexes. The test results showed that at a travel speed of 7.2 km/h when the edge angle of cutting was 65°, the rotation radius of the knife was 420 mm, and the rotation speed of the knife roller was 538~600 rpm, the straw clearing rate was ≥85%, and power consumption was ≤1.5 kW. The field test was carried out to verify the optimized results, and the test results showed that the test values of the performance evaluation indexes were all in the ranges of the optimized interval. These research results lay down the foundation for the design of lateral straw clearing and throwing knives.