Simulation and Identification of Multiscale Falling Morphology of Fresh Tea Leaves at Different Transport Speeds Based on Discrete Element Method

To explore the falling morphology of multiscale fresh tea leaves at different speeds, this study evaluated the multiscale fresh tea leaves (one bud with two leaves, one bud with one leaf, single leaf, and damaged leaf) at different heights (0.7 m, 0.5 m, 0.3 m, and 0.1 m from the ground) during the process of dropping on the conveyor belt at different speeds (0.6 m/s and 1.2 m/s). The motion morphology of fresh tea leaves on multiple scales was analyzed by discrete element simulation, the results showed that the movement patterns of multiscale fresh tea leaves at different positions from the ground were different when the conveyor was dropping at different speeds, and that the multiscale fresh tea leaves all rotated around the long axis, short axis, and root of the fresh tea leaves. When the conveying speed of the conveyor belt was 0.6 m/s, the movement patterns of one bud with two leaves and of one bud with one leaf of fresh tea were near the ground, and the movement patterns of the fresh tea leaves were mostly oriented toward the ground. The leaf tips of the fresh tea leaves were mostly on the side near the ground, the damaged leaves were near the ground, and the movement patterns of the fresh tea leaves were mostly parallel to the ground. When the conveyor belt throwing speed was 1.2 m/s, the roots of one bud with two leaves moved toward the ground when they were close to the ground. When one bud with one leaf was close to the ground, the leaf tip moved toward the ground, and the single leaf and damaged leaf rotated around the root because of the inertia of the conveyor belt throwing.