Oct 2026· Horttechnology· 0 citations· 21 references
Abstract
To address the problems of low sorting accuracy and poor operation stability caused by physical leaf entanglement in traditional drum screening of fresh tea leaves, a multiscale fresh tea leaf sorting system with drum-axial airflow coupling based on intelligent control was designed. The axial moving distances of fresh tea leaves of different scales at wind speeds of 5, 7, and 9 m/s were calibrated through bench tests, and the optimal wind speed parameter for secondary fine screening was determined. A numerical model of the axial airflow field inside the drum was established via Fluent software, and a coupled sorting test platform was built to compare the sorting performance of the traditional pure drum screening mode and that of the coupled intelligent sorting mode. The results showed that 7 m/s is the optimal axial airflow velocity for secondary fine screening of multiscale fresh tea leaves during this test, which can realize effective back-blowing of small-scale materials and accurate screening of large-scale materials. At this velocity, the flow field is evenly distributed, and the effective thrust area highly matched the sorting demand. The average sorting efficiency of the coupled intelligent sorting mode reached 84.8%, which is 25.6% higher than that of traditional pure drum screening, with favorable sorting accuracy and operation stability. These findings can provide a theoretical basis and technical reference for the optimization, upgrading, and intelligent transformation of high-efficiency fresh tea leaf sorting equipment.
This study describes a self-developed intelligently controlled drum–axial airflow coupled sorting device. Using the sorting rate as the evaluation index, single-factor tests were conducted to analyze the influence patterns of axial airflow startup time, drum rotational speed, and axial airflow velocity on the sorting effect. The Box-Behnken response surface design method was adopted to construct a quadratic regression model for the sorting rate, analyze the interaction between factors, and conduct parameter optimization and verification. All three test factors had an extremely significant effect on the sorting rate. Among them, the quadratic effect of axial airflow velocity was the strongest, and parameter fluctuations had the highest sensitivity to the sorting results. Significant coupling interaction between axial airflow startup time and drum rotational speed was observed. Through global optimization, the following optimal process parameter combination was obtained: axial airflow startup time, 6.5 s; drum rotational speed, 16 rpm; and axial airflow velocity, 7.5 m/s. Under these conditions, the measured average sorting rate reached 80.46%, with a relative error of only 1.03% compared with the model predicted value, indicating good model prediction accuracy. These results can provide a theoretical basis and technical support for the research and development of intelligent sorting equipment for multiscale fresh tea leaves and optimization of process parameters.
Traditional tea harvesting methods often lack precision, leading to significant leaf damage and reduced operational efficiency. To address these limitations, this paper proposes an airflow-driven end-effector designed for selective tea harvesting, utilizing pneumatic transport to move harvested leaves from the shearing interface to storage. A theoretical model based on force equilibrium was developed to determine the critical transport velocity (CTV), calculated to be approximately 3.6 m/s. The theoretical prediction was further evaluated through CFD analysis using ANSYS Fluent with a k–ω Shear Stress Transport (SST) turbulence model across inlet velocities ranging from 2.5 m/s to 4.5 m/s. Simulation results indicate that inlet velocities at or above 3.6 m/s provide airflow conditions favourable for sustained pneumatic leaf transport, with 4.5 m/s achieving outlet velocities up to 6.586 m/s and mass flow rates of approximately 1.59×10−3 kg/s, while lower velocities fail to maintain sufficient transport momentum. Despite considerable velocity decay along the transport path, adequate velocity is retained in critical regions for sustained pneumatic conveyance. These findings demonstrate the feasibility of airflow-based transport for selective harvesting and provide a quantitative basis for optimizing end-effector design.
Sharamjeet Shaurya, Arjun Agarwal, Dhirendra Kumar Verma et al.· International Conference on...· 0 citations
The convective drying of agricultural materials is an energy-intensive process, and optimizing dryer design is critical for improving efficiency and product quality. This study presents a comprehensive heat and mass transfer model for the convective drying of alfalfa leaves in a rotary drum dryer. Freshly harvested leaves with an initial moisture content of approximately 70% (w.b.) were used as the test material. The proposed system features a simplified drum design aimed at enhancing process efficiency while reducing equipment complexity. The primary objective was to reduce the moisture content of alfalfa leaves to below 50% to ensure their quality during subsequent storage and transportation. To determine the optimal operating conditions, the kinematics of leaf motion inside the rotating drum and the associated heat and mass transfer phenomena were investigated through analytical modeling, numerical simulation, and experimental studies on a laboratory-scale physical model. An analytical model was developed to establish relationships between transverse kinematic characteristics (detachment condition, Froude number, drum inclination angle), average longitudinal velocity, and residence time. Numerical simulations based on the Navier–Stokes equations (continuity, momentum, and energy) provided detailed moisture content distributions within individual leaves under varying airflow orientations and drying durations. The novelty of this work lies in the integrated determination of optimized operating parameters through combined analytical, numerical, and experimental approaches. A regression model relating final moisture content to key process variables (air velocity, temperature of 60 °C, drum rotation frequency and mass of loaded material) was developed from experimental data, yielding practical recommendations for the design and operation of rotary drum dryers for alfalfa and similar agricultural materials.
Gani Zhumatay, O. Zhortuylov, K.A. Moshanov et al.· Applied Sciences· 0 citations
A modular and automated cleaning device for floating solid waste was developed to tackle the problems of low collection efficiency, high energy consumption, and frequent clogging in rural ditches and ponds. According to field monitoring data, the inlet velocity and filter mesh size were determined. The device comprises a cleaning module, a collection module, and a bottom filter connected in series, which is driven mainly by gravity with low-power electric control as assistance. CFD and FEA were employed to simulate the flow field around the cleaning roller, the stress of the retention plate, and the head loss of the bottom filter. The results demonstrate that the flow field on the cleaning roller is stable, and the maximum velocity exhibits a linear relationship with the inlet velocity. The maximum equivalent stress of the retention plate is 38.6 MPa, and the rubber head can absorb more than 80% of the impact energy. With a 3 mm aperture for the bottom filter, the head loss is about 26 mm at the designed flow rate, achieving a good balance between interception efficiency and low flow resistance. The device can effectively intercept floating waste such as plastics and straws, making it suitable for routine cleaning of small rural water bodies.
In view of the urgent need for pollination equipment for existing hybrid rice and the practical problems of traditional manual pollen-driving, such as high labor intensity, low efficiency, and easy-to-break rice stems, an automatic pollen-driving system combining traditional manual and mechanical auxiliary control was designed. According to the analysis of the driving process, the driving speed v and the rope height h are the main factors affecting the bending degree of rice stems (the cross-section angle θ of rice stems). Through shear and extrusion tests, the characteristic parameters of rice stems and the bonding parameters of the rice stem bonding model were obtained. The test results showed that when the bending angle of the rice stem was 47°, the maximum shear force of the rice stem was 5.42 N. A quadratic orthogonal rotation combination simulation test was carried out using the discrete element method (EDEM), and the optimal parameter combination of powder driving speed and rope height was determined. The angle error between the measured angle value and that obtained by the constraint solving tool of Design-Expert software was less than 5%. Furthermore, combined with field experiments, through the optimization of the pollen-driving operation parameters, the phenomenon of rice breakage was reduced in the process of pollen-driving. Therefore, the research in this paper can provide certain references for the design of hybrid rice powder-driven systems and the optimization of operating parameters.
Physical control technology as an alternative to chemical pesticides is of great significance for modern sustainable agriculture. However, small pests such as tea green leafhoppers and tea thrips possess sensitive aerodynamic receptors that easily perceive disturbances generated by suction airflow and initiate stress-induced escape behavior. The current bottleneck in the state of the art is that conventional straight tube capture devices generate severe airflow pulsations and turbulence near the intake which act as alarm signals causing pests to escape before entering the effective capture zone. To resolve this trade-off, this study developed and validated a variable cross-section wind-suction channel based on the principle of biological behavioral suppression. This design incorporates a three-stage functional structure consisting of a flow-stabilizing intake section a guided acceleration section and a high negative-pressure throat to achieve a synergistic balance between low disturbance induction and strong aerodynamic confinement. Numerical simulations and prototype experiments show that this design establishes a stable rectified environment at the intake with relative wind speed deviations within 5%. Under controlled laboratory conditions, the average capture rate for target pests exceeded 85% within an effective operating radius of 20 cm. Comparative biological validation further confirms that the capture efficiency of this design is improved by more than 32 percentage points compared with a conventional straight-tube benchmark device. Furthermore, the critical stress-response distance was reduced by approximately 50%, significantly enhancing the concealment of the capture process. These findings elucidate the critical role of channel geometry in resolving the conflict between suction intensity and environmental disturbance providing a theoretical foundation and technical support for the development of high efficiency and precision plant protection equipment.
Qiang Wu, Zhu Chen, Huihua Ji et al.· Agronomy· 0 citations
Related blog posts
MIT News · Artificial Intelligence· news.mit.eduAug 17, 2026
A USAF cadet and a Lincoln Laboratory researcher found AI chatbots can help nontechnical service members produce viable software applications for their unique problems.
