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.
Precision farming technologies require regular, highly detailed monitoring of agricultural lands, producing comparable crop condition maps. Hybrid vertical takeoff and landing unmanned aerial vehicles (tiltrotors) are a promising tool for solving these problems, however, their use in drone port infrastructure places special demands on their design, particularly on clearances in the powerplant beam and hatch opening systems. The aim of the study is to numerically simulate the effect of design gaps on the aerodynamic characteristics of Bars-type tiltrotor, assess their impact on the operational performance of agricultural monitoring and develop engineering recommendations. The study was conducted using a 3D model and ANSYS Fluent package. Three gap options were considered: 0, 10 and 30 mm. It was found that crevice leaks in the hatch-to-skin zone lead to the formation of vortex structures and flow separation zones, causing a decrease in the aerodynamic quality K. The maximum K decreases from 13.1 (0 mm) to 9.8 (10 mm) and 6.6 (30 mm), with drag increasing by 10-40%. In terms of operational performance, this corresponds to a reduction in takeoff duration by 9-13% (with a gap of 10 mm) and by 29% (with a gap of 30 mm). The area surveyed per flight is reduced by 11-18 hectares and 35-40 hectares, respectively. The specific cost of monitoring increases: with a 10 mm clearance, it reaches 71-75 rubles/ha (economy segment) and 440-575 rubles/ha (high detail); with a 30 mm clearance, it reaches 92-107 rubles/ha and 564-705 rubles/ha, respectively. Minimizing technological gaps and using sealing solutions in hatch assemblies are critical measures to ensure productivity, flight regularity and cost-effectiveness of monitoring.
A. V. Dmitriev, V. Zinurov, Aleksandr Vyacheslavovich Solovev et al.· Vestnik of Kazan state agrar...· 0 citations
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
This study experimentally investigates the aerodynamic response of a laboratory-scale, wind-assisted solar chimney fitted with a NACA airfoil above its outlet. Thermal forcing was excluded to isolate wind–airfoil interactions. A Taguchi L25 orthogonal array assessed the effects of wind velocity, horizontal displacement, vertical stand-off distance, and airfoil angle on average chimney velocity, while ANOVA quantified factor contributions. The highest L25 response was 4.0675 m s−1 at 10 m s−1, +10 mm, 40 mm, and +10°, with triplicate validation yielding 4.070 ± 0.191 m s−1 (U95, k = 2). Taguchi main-effects analysis identified favourable levels of 10 m s−1, 0 mm, 50 mm, and +10° and ranked factor influence as wind velocity > airfoil angle > horizontal displacement > vertical distance. ANOVA showed that airfoil angle and wind velocity dominated the response, contributing 37.43% and 31.20%, respectively. These findings demonstrate that chimney airflow is highly sensitive to the outlet-airfoil configuration under controlled aerodynamic conditions.
Atılgan Temir, İ. Üçgül· Japanese Journal of Applied...· 0 citations
The π-shaped section, as a typical blunt section, exhibits significant airflow separation around its section, making it susceptible to wind-induced vibrations. To investigate the flutter mechanism and control measures of a π-shaped section, the Ebtehaj cable-stayed bridge is taken as a case study. Wind tunnel tests and numerical simulations are combined to examine the effects of an upper central stabilizer and a spoiler. The differences in the flutter control performance are clarified through analyses of the spatiotemporal evolution of vortices and the characteristics of zonal aerodynamic work. The results show that an upper central stabilizer with a height of two-thirds of rib height can completely eliminate divergent vibration, while, within the tested parameter range, 60° is identified as the optimal aerodynamic angle for the spoiler. The upper central stabilizer suppresses flutter by modifying the vortex distribution over the upper surface, interrupting the vortex correlation between the upstream and downstream regions of the stabilizer and enhancing vortex interactions in the wake region. However, the spoiler primarily regulates the flow by suppressing vortex generation on the upper surface and altering the vortex distribution on the lower surface. From an energy perspective, the central stabilizer enhances the negative aerodynamic work at the leading edge while altering the aerodynamic work characteristics at the trailing edge. The spoiler, on the other hand, significantly strengthens the negative aerodynamic work at the leading edge and changes the aerodynamic work in the mid-leading-edge region from negative to positive.
Shuo-Han Zhao, Feng Wang, Jianming Hao et al.· The Physics of Fluids· 0 citations
: In the fields of aviation engineering and fluid dynamics, optimizing the aerodynamic performance of gliders is crucial for improving flight efficiency. Wind tunnels are a crucial component of aerodynamics research. Nowadays, there have been significant advancements in control systems, control technologies, and instrumentation for wind tunnels. The development of aerodynamics intersects with multiple disciplines — for example, researching the ablation of aircraft surface materials and mass injection under high-temperature conditions involves disciplines such as high-temperature gas dynamics and multiphase flow. However, measurement technologies still have limitations: certain parameters are difficult to measure, such as shock wave structures in high-speed flows, the instantaneous characteristics of turbulence, and pressure and velocity distributions in complex flow fields. This experiment takes a paper airplane as a model and uses the control variable method to design three sets of gliders with different aspect ratios (AR) and wing areas. The flight trajectory data is obtained using Tracker video analysis software to quantitatively analyze the relationship between lift-to-drag ratio and wing geometry parameters. When the aspect ratio increases, the gliding angle decreases, and the lift-to-drag ratio significantly increases. The study provides a low-cost experimental paradigm for the aerodynamic design of micro air vehicles, revealing the influence of key geometric parameters of unpowered gliding bodies on lift-to-drag ratio. This study establishes a low-cost experimental paradigm and fills the gap in the study of aerodynamic characteristics of micro unpowered gliders. Its method can be extended to analyze other low-speed aerodynamic systems.
Yule Lin· Proceedings of the 3rd Inter...· 0 citations
Politecnico di Milano is undergoing the design of a highly swept, low-aspect-ratio radio-controlled aircraft with reflex airfoils. This model is necessary to expand the automated flight-testing activities conducted inside the university, adding to the flying models a more unconventional one to verify the flight-testing technique implemented. Plain-type spoilerons were investigated as primary roll control devices and compared with conventional aerodynamic predictions and wind-tunnel data. The experimental tests assessed performance across spanwise and chordwise positions, angles of attack, and spoileron geometric variations. A normalized control effectiveness parameter, accounting for moment coefficient, spoileron surface area, and moment arm, was introduced to compare configurations. Results show consistent peak performance at intermediate incidence and highlight distinct degradation patterns near stall. Spanwise variations primarily affect roll authority, while yaw response remains weakly sensitive. Geometric analysis indicates span increases are more efficient than chord increases for equivalent performance, reducing actuator loads and aerodynamic penalties.
Riccardo Andrew Oggioni, C. Riboldi, Filippo Coacci· IOCAE 2026· 0 citations
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