CFD Simulation and Optimization of the Leaf Collecting Mechanism for the Riding-Type Tea Plucking Machine

Abstract

In the process of tea plucking and leaf gathering, the structure optimization design of the leaf collecting mechanism is the key element responsible for collecting fresh leaves. The unreasonable design and manufacture of leaf collecting mechanisms will cause the smooth collection of fresh leaves, the quality of the collected fresh leaves will be damaged, and the commodity value will be reduced. In order to further study the structural characteristics of the leaf collecting mechanism, an air outlet model of the leaf collecting mechanism was established for the phenomena of internal vortex rotation and impact in the leaf collecting mechanism process. The internal flow field of the leaf collecting mechanism, the movement trajectory of fresh leaves, and the non-homogeneous flow are calculated using computational fluid dynamics (CFD). Based on Box-Behnken’s central combinatorial design theory, the velocity inlet and outlet air structure factors are taken as the influencing factors to carry out response surface test research. The effect of different parameters such as engine rotation, shape of the blowing cavity and air outlet parts, and velocity on the flow is determined. The optimal parameter combination is as follows: the height of the outlet end, the length of the inlet end, and the velocity inlet are 0.01 m, 0.03 m, and 25 m/s, respectively. Furthermore, it was found that when the number of plates increases from 1 to 4, the non-homogeneity decreases all the time, and the distribution of blowing air is improved without a sharp decrease in velocity. The average velocity outlet was larger than the velocity inlet, which meets the requirements of blade gathering. Considering comprehensively, the flow field simulation of the blade collecting mechanism with four baffles was consistent with the test results of the velocity outlet. The validation results showed that the model can successfully simulate the air flow inside the leaf-collecting mechanism, and the reasonable structure design was conducive to reducing the number of collisions between tea buds and improving the quality of tea buds. This research has certain theoretical and practical implications for the accurate plucking of high-quality tea.

Design and Experiment of Profiling Furrow-Ridge Terrain by Cane Leaf-Chopping and Returning Machine

“…Meanwhile, in another situation shown in Figure 6a, the cane leaves attached to the As per the measured topography in Figure 2, the width of furrow base fluctuates more significantly than the depth. Therefore, the concentration of hook teeth arrangement is an important variable affecting their picking ability for changing furrow profiles, as also demonstrated by study [24]. In order to experiment with better profiling capabilities, by adjusting horizontal teeth spacing for a fixed number of teeth, the available range of action of hook teeth could best adapt to the morphological changes of furrows.…”

Optimizing Efficiency of Tea Harvester Leaf-Collection Pipeline: Numerical Simulation and Experimental Validation

“…Li et al [10] designed an air-assisted cutting table featuring a duckbill nozzle for optimal residual-free cutting and simplified machine maintenance. Wen et al [11] created a model to make uniform the outlet air velocity of a collector leaf mechanism and optimized its parameters using the Box-Behnken design theory. Liu et al [12] conducted a numerical study on the gas-solid flow in a conveyor using a coupled CFD and DEM method, focusing on how contraction and diffusion angles affect the airflow field and seed motion.…”