Determination of Interspecific Contact Parameters of Corn and Simulation Calibration of Discrete Element

In order to get the optimal solution by comparative tests, the simulation analysis was widely used during the development process of air suction seed metering device. The gas-solid coupling simulation method was compatible because the single grain rate of air suction seed metering device was reached by different air pressures, and the process was filled with variable flow field and moving particles. The difference of contacting parameters between the simulation particle and the real particle would be bigger when the bonding particle model was implied during the coupling of Fluent. In order to solve the problem, the reasonable variable range during the process of calibrating the discrete element parameters was reached with the measured values of contact parameters between maize species. The steps were as follows: the rolling friction and the static friction of corn-corn were measured by slope method and energy conservation method of high speed photography. The linear function between the zero level of variable range and the measured value was established (the best calibration range of zero level was equal to the measured coefficient value of coefficients ) . In order to find the optimal coefficient value, six groups of different coefficients were selected to solve the variable range, and the response surface optimization method was applied to optimize and calibrate the corn interspecific contact parameters with the real measurement of corn accumulation angle as the objective quantity. The accumulation angle of simulation was obtained by calibrations parameters and compared with the real accumulation angle got by lifting tests. The relation between curve of accumulation angle was calculated by different coefficients values. The value of optimized parameter during the calibration range was the most accurate when the coefficient was 0. 197 7. The best combination of fixed parameters was as follows; the static friction coefficient between corns was 0. 031, the rolling friction coefficient between corns was 0. 003 9. There was no significant difference between the simulation results of the simulation results of the best parameter with the real experiment. The results showed that the contact parameters of the calibrated discrete element of corn were reliable. Those parameters and calibration methods can be set as references for the selection of calibration parameter range in the simulation process of follow-up air suction seed metering device. © 2022 Chinese Society of Agricultural Machinery. All rights reserved.