Analysis of jujube movement characteristics under positive and negative pressure airflow based on CFD-DEM

Current study was conducted to explore the jujube kinematic characteristics in the pneumatic pickup device's operation under positive and negative pressure airflow to optimize its working parameters. This study designed a CFD-DEM coupling simulation system of the device in operation. Here, we investigated the kinematics of internal airflow and the jujube equivalent under its action. Following that, the pickup rate and loss rate of the equipment were used as response indicators, and the weight analysis method was used to calculate the forward speed and negative and positive pressure airflow velocity. The optimal parameter combination were 0.26 m/s, 35 m/s, and 20 m/s. At the same time, the pickup rate and loss rate of the model predicted were 99.20% and 0.75%, respectively. Results from the field experiment showed that the pickup rate and loss rate were 98.43% and 0.80%, which error with the predicted values were 0.78% and 6.67%. The research is not only of great significance for research on pneumatic landing jujube pickers but has also great reference value to the construction and methods of the CFD-DEM coupling simulation systems.