CALIBRATION OF WHITE RICE SIMULATION PARAMETERS BASED ON DISCRETE ELEMENT METHOD

Abstract

Aiming at the lack of discrete element simulation models and parameters for rice polishing, grading, color sorting and other technologies and equipment, and the difficulty of guiding equipment design and optimization through simulation, this paper calibrates the simulation parameters of white rice based on angle of repose (AOR) test and simulation methods. Huanghuazhan and Dongnong 429 white rice were selected as research object. Numerical model of white rice was established by multi-sphere filling. According to physical test and references, the simulation parameter range of white rice particles was determined. Plackett-Burman test was used to screen parameters, and it was found that the particle-particle static friction coefficient and particle-particle rolling friction coefficient had significant effects on the AOR of white rice. The regression model between the AOR and the significance parameter was established according to the central composite design method. The simulation parameter combination that has significant influence on the physical AOR was determined through the optimization design, and verified by the simulation test. The simulation AOR was compared with the physical AOR, and the relative error of the two kinds of white rice was less than 3%. The results show that the calibration method proposed in this study can accurately simulate the physical AOR test, which can provide reference for discrete element simulation of white rice processing.