A Fluent-based phototactic small-volume insect trapping channel

Abstract

This invention discloses a fluent-based phototactic small-volume insect trapping channel, comprising a plastic outer shell. The outer shell is divided into an inlet section, an arc-shaped middle section, and an outlet section. The inlet section has an open structure, and the outlet section connects to an insect-collecting device. The inlet section includes an air inlet on the lower surface of the outer shell, with four equally spaced guide vanes fixedly installed inside the air inlet. A central cylinder is fixedly installed at the center of the inner side of the air inlet, and an axial flow fan is installed at the upper end of the central cylinder. This fluent-based phototactic small-volume insect trapping channel employs a novel structural design. The turbulence in the inlet section is treated by the expansion angle of the guide vanes and the smooth inner wall. The arc-shaped middle section, through curvature design and air knife assistance, completely suppresses eddies below the escape trigger threshold of small insects, eliminating alert escape. Furthermore, the entire internal channel of the device achieves uniform high-velocity flow, forcibly disrupting the flight posture of small-volume insects, thus achieving efficient capture.

Description

Technical Field

[0001] This invention relates to the field of insect capture technology, specifically to a fluent-based phototactic small-volume insect capture channel. Background Technology

[0002] Currently, insect traps are needed to control pests and diseases in tea gardens, vegetables, cash crops, and fruit trees. These traps are typically used to capture insects and control pests. They are usually created using negative pressure adsorption or attraction by light and bait.

[0003] In the prior art, Chinese Patent Application No. CN20211110903.1 discloses a wind-suction type insect trapping device, including a support column, a base at the bottom of the support column, a wind-suction type odor attractant at the top of the support column, an electrical control box supported by a hollow column above the wind-suction type odor attractant, and a solar panel at the top of the electrical control box; the wind-suction type odor attractant includes an insect trapping box, a trapper, and an attractant component; an insect collection box is located at the bottom of the insect trapping box; the trapper includes an air duct with the top of the insect trapping box and external connection; a fan is located on the inner wall of the air duct; a cover plate is located at the bottom of the air duct; a drive component is located on the outer wall of the air duct to drive the cover plate to automatically fold; a wind-blocking impact plate is located around the top of the air duct; and the attractant component is located between the trapper and the electrical control box.

[0004] For example, in the prior art, Chinese patent application number CN202020374539.4 discloses a wind-suction physical insect trap, including a base, several support rods fixed to the outer edge of the base, an upper box fixed to the support rods, an insect-attracting lamp tube and an upper fan fixed to the bottom of the upper box; an insect-collecting device is provided below the base, and a lower fan is fixed below the insect-collecting device.

[0005] For example, in the prior art, Chinese Patent Application No. CN201880067401.5 discloses an insect trap, including a main body with a fan inside and an opening at the top to expose the fan to the outside; an upper cover with a light source for irradiating ultraviolet light and configured to open and close the top of the main body; and an insect passage portion disposed on the top of the main body and covering a portion of the opening, wherein the area covered by the insect passage portion in the area of ​​the opening is greater than or equal to the area of ​​the opening that is not covered by the insect passage portion.

[0006] Based on the above materials, it can be seen that most existing technologies use a combination of attraction and negative pressure adsorption to achieve the purpose of capture. However, in actual use, the capture of small insects has not been very effective. Because the movement trajectory of small insects is different from that of larger insects, conventional wind suction trapping methods are difficult to capture them. Small insects such as leafhoppers and whiteflies can easily escape even if they are trapped. Furthermore, small insects have very weak lift in flight but are extremely sensitive to airflow disturbances. Empirical structural designs, such as right-angle corners and abrupt changes in pipe diameter, are not sufficient for the efficient capture of small insects. Summary of the Invention

[0007] The purpose of this invention is to provide a fluent-based phototactic small insect capture channel to solve the problem of poor capture effect for small insects mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a fluent-based phototactic small-volume insect-catching channel, comprising a plastic device shell, the device shell being divided into an inlet section, an arc-shaped middle section, and an outlet section. The inlet section has an open structure, and the outlet section is connected to an insect-collecting device. The inlet section includes an air inlet located on the lower surface of the device shell, and four equally spaced guide vanes are fixedly installed inside the air inlet. A central cylinder is fixedly installed at the middle position inside the air inlet, and an axial flow fan is installed at the upper end of the central cylinder. The arc-shaped middle section includes a single-curvature arc surface located on the back of the device shell, and the outlet section includes an outlet baffle fixedly installed at the upper end of the device shell.

[0009] Preferably, an LED insect-attracting lamp is fixedly installed at the bottom of the central cylinder, and an integrated sensor module is fixedly installed on the inner wall of the guide plate, wherein the sensor module includes a wind speed sensor and an infrared sensor.

[0010] Preferably, a 4G transceiver module is fixedly installed on the top of the device housing, and a high-speed camera is fixedly installed above the outlet baffle.

[0011] Preferably, an air knife is fixedly installed in the middle of the inner wall of the single-curvature arc surface, and the radius of the single-curvature arc surface is 25cm, and the central angle corresponding to the single-curvature arc surface is 60°, with the air knife embedded in the center of the single-curvature arc surface.

[0012] Preferably, the angle between the guide vane and the horizontal axis is 15° and forms an expansion structure.

[0013] Preferably, the outlet baffle forms an 8° contraction angle with the vertical axis, gradually converging the airflow and forming a strong suction zone at the end before the outlet.

[0014] Preferably, the LED insect-attracting lamp uses low-power LED beads, and the LED insect-attracting lamp and the central cylinder adopt a plug-in installation structure.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This fluent-based phototactic small-volume insect-catching channel adopts a novel structural design, the details of which are as follows:

[0016] 1. The turbulent flow at the inlet section is treated by the expansion angle of the guide vanes and the smooth inner wall. The curved middle section is completely suppressed by the curvature design and the assistance of the air knife. The eddies are completely suppressed below the escape trigger threshold of small insects, eliminating alarm-induced escape. Furthermore, the entire internal channel of the device achieves uniform high flow velocity to forcibly disrupt the flight posture of small insects, thus achieving efficient capture.

[0017] 2. A linear pressure gradient is formed from the inlet section to the arc-shaped middle section to the outlet section, which guides the movement of small insects in a directional manner and forces them to move towards the outlet with the airflow, thus avoiding stagnation. In addition, the internal channel of the device is an integrated smooth structure without the physical gaps of traditional mechanical covers. It replaces mechanical interception with a dual flow field barrier of "flow velocity + turbulence", achieving precise physical interception of small insects.

[0018] 3. The airflow guide plate integrates a sensor module, including a wind speed sensor and an infrared sensor. The wind speed sensor detects real-time changes in wind speed inside and outside the channel, automatically adjusting the fan power to ensure stable airflow within the channel, unaffected by external gusts. This maintains sufficient airflow intensity to capture small insects, avoiding instability in capture results due to wind speed fluctuations. It adapts to complex wind environments in the field, enhancing the automation and practicality of the equipment.

[0019] 4. An LED insect-attracting lamp is installed at the bottom of the central cylinder. The low-power LED insect-attracting lamp with a specific wavelength can effectively attract target small insects (such as tea green leafhoppers, whiteflies, etc.) to gather at the entrance of the channel, increase the insect density at the entrance, enhance the efficiency of wind suction capture, and the lamp has low power consumption, so it will not increase the energy consumption of the equipment too much. Moreover, the installation position does not interfere with the airflow stability in the channel, reduce the false attraction of non-target insects, and work together with the wind suction function to improve the capture of specific pests while saving energy.

[0020] 5. High-speed cameras are installed at the exit section to clearly record insects entering the channel. In conjunction with the cloud-based identification system, the captured insects can be automatically counted and classified, eliminating the need for manual counting. This allows for convenient remote monitoring of insect activity in real time. The accumulated data can help analyze insect activity patterns, optimize capture strategies, provide accurate data for pest control, reduce the workload of manual inspections, and enhance the intelligent monitoring capabilities of the equipment. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0022] Figure 2 This is a schematic diagram of the back structure of the outer casing of the device of the present invention;

[0023] Figure 3 This is a schematic diagram of the cross-sectional structure of the outer casing of the device of the present invention;

[0024] Figure 4 This is a vector diagram of the simulated velocity of the present invention;

[0025] Figure 5 This is a simulated pressure cloud diagram for the present invention;

[0026] Figure 6 This is a cross-sectional turbulence cloud diagram of the present invention;

[0027] Figure 7 This is a simulation trajectory diagram of the present invention.

[0028] In the diagram: 1. Device housing; 2. Air inlet; 3. Guide vane; 4. Central cylinder; 401. Axial flow fan; 5. Sensor module; 6. LED insect attractant lamp; 7. Single curvature arc surface; 8. Air knife; 9. 4G transceiver module; 10. Outlet baffle; 11. High-speed camera. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1: Please refer to Figures 1-3 This embodiment provides the following technical solution, specifically disclosing: a plastic device shell 1, which is divided into an inlet section, an arc-shaped middle section, and an outlet section. The inlet section has an open structure, and the outlet section is connected to the insect collection device. The inlet section includes an air inlet 2 opened on the lower surface of the device shell 1, and four equally spaced guide vanes 3 are fixedly installed on the inner side of the air inlet 2. A central cylinder 4 is fixedly installed at the middle position of the inner side of the air inlet 2, and an axial flow fan 401 is installed on the upper end of the central cylinder 4. The arc-shaped middle section includes a single-curvature arc surface 7 set on the back of the device shell 1. The outlet section includes an outlet baffle 10 fixedly installed on the upper end of the device shell 1.

[0031] An LED insect-attracting lamp 6 is fixedly installed at the bottom of the central cylinder 4, and an integrated sensor module 5 is fixedly installed on the inner wall of the guide vane 3. The sensor module 5 includes a wind speed sensor and an infrared sensor. A 4G transceiver module 9 is fixedly installed on the top of the device housing 1, and a high-speed camera 11 is fixedly installed above the outlet baffle 10 and is fixedly installed with the device housing 1. An air knife 8 is fixedly installed in the middle of the inner wall of the single-curvature arc surface 7. The radius of the single-curvature arc surface 7 is 25cm, and the central angle corresponding to the single-curvature arc surface 7 is 60°. The air knife 8 is embedded in the center of the single-curvature arc surface 7. The angle between the guide vane 3 and the horizontal axis is 15° and forms an expansion structure. The outlet baffle 10 forms an 8° contraction angle with the vertical axis, gradually converging the airflow and forming a strong suction zone at the end in front of the outlet. The LED insect-attracting lamp 6 uses low-power lamp beads, and the LED insect-attracting lamp 6 and the central cylinder 4 adopt a plug-in installation structure.

[0032] The main body of the channel is a variable-diameter arc-shaped integrated structure, which is divided into three sections: inlet section, arc-shaped middle section, and outlet section. The inlet section consists of three parts: a four-sided fan-shaped inlet surface with a diameter of 15cm, four guide vanes 3 with rounded corners, and a central cylinder 4. The guide vanes 3 form an expansion structure with a 15° angle to the horizontal axis, which allows the initial turbulence at the fan inlet to quickly transition to laminar flow characteristics, rapidly reducing the turbulence intensity and preventing the inlet vortex from startling small insects that are sensitive to airflow disturbance. The inner wall of the guide vanes 3 integrates a wind speed sensor and an infrared sensor. The wind speed sensor is used to monitor the wind speed in the channel and is also connected to the drive circuit of the axial flow fan 401 to control the output power of the axial flow fan 401. When changes in the external environment cause changes in the flow velocity in the channel, the output power of the axial flow fan 401 is adjusted to ensure the stability of the flow velocity in the channel. One end of the guide vane 3 is connected to the inner wall of the channel, and the other end is connected to the central cylinder 4. The upper end of the central cylinder 4 is used to fix the axial flow fan 401, and the lower part of the central cylinder 4 is equipped with a low-power LED insect-attracting lamp 6, which adopts a plug-in design for easy replacement.

[0033] The arc-shaped middle section consists of a single-curvature arc surface 7 with a curvature radius of 25cm and a wind knife 8. The unit center of the single-curvature arc surface 7 is outside the channel, and the corresponding central angle of the single-curvature arc surface 7 is 60°. The smooth turning design of the arc-shaped middle section without right angles eliminates the vortex trigger point of traditional corners, adapting to the low-disturbance flow field requirements of small insects. The wind knife 8 is embedded in the curvature center of the upper surface of the arc-shaped middle section, which can break the rotation structure of the vortex, break the large-scale vortex into small-scale turbulence, reduce the escape caused by airflow disturbance, and guide the airflow to turn evenly, making the axial pressure gradient more linear and continuous. A 4G transceiver module 9 is installed on the outer top of the single-curvature arc surface 7.

[0034] The outlet baffle 10 forms an 8° contraction angle with the vertical axis, gradually converging the airflow and forming a strong suction zone at the end before the outlet. This forcefully guides small insects into the insect collection chamber, preventing them from escaping. A high-speed camera 11 is installed above the outlet. When a small insect is sucked into the channel, it triggers the infrared sensor at the guide vane 3, activating the high-speed camera. The camera takes a picture and uploads it to the cloud server, where AI algorithms identify and count the insects. The insect situation is monitored through the Internet of Things.

[0035] Example 2: Taking the capture of the tea green leafhopper as an example

[0036] The key criterion for capturing the tea green leafhopper is the resistance generated by the airflow within the air intake channel. It needs to be greater than its own flight lift. ,Right now .

[0037] The adult tea green leafhopper is about 2-4 mm long, with an average value of L=3.5 mm.

[0038] The adult insect's body diameter is approximately d=1mm, and its windward surface area is:

[0039]

[0040] Insects are considered blunt-bodied. According to the "Aerodynamics and Flight Mechanics Research of Insect Flight", the drag coefficient of small insects similar in size to the tea green leafhopper (such as aphids and whiteflies) in turbulent conditions ranges from 1.2 to 1.5. The maximum value is taken. =1.5.

[0041] 1. Under ideal experimental conditions (no natural wind interference, constant temperature)

[0042] Based on the duct simulation results, the flow velocity inside the duct is 15-20 m / s, and the minimum value V=15 m / s is taken.

[0043] The density of air at standard atmospheric pressure is ρ = 1.225. .

[0044] Dynamic airfoil theory for calculating flight drag F D :

[0045]

[0046] The tea green leafhopper has a mass of approximately 1 mm and a flight lift of [missing information].

[0047]

[0048] at this time The capture conditions are met.

[0049] 2. Verification under the influence of natural wind interference, temperature change, and humidity change

[0050] Let the speed of the external gust be The value ranges from 0.5 to 3 m / s, and the direction is opposite to the channel inlet axis (most unfavorable working condition). The attenuation coefficient of the guide plate for the reverse wind speed is k. Based on the fluid flow theory, the attenuation coefficient k=2 for a 30° inclined guide plate, that is, only 20% of the external wind energy penetrates the guide plate and enters the channel.

[0051] Take the maximum value of the outside wind speed Then the reverse interference wind speed entering the channel:

[0052]

[0053] Actual effective wind speed within the passage:

[0054]

[0055] The atmospheric density (humid air density) under the combined effects of temperature and humidity can be used to calculate the impact of temperature and humidity on insect trapping efficiency, based on the ideal gas law and the humid air mixing model, combined with the effects of temperature on saturated vapor pressure and humidity on gas composition.

[0056] Moist air is composed of dry air and water vapor, and its total density is equal to the density of dry air. and water vapor density sum:

[0057]

[0058] Standard atmospheric pressure P = 101325 Pa, actual partial pressure of water vapor is The partial pressure of dry air is:

[0059]

[0060] dry air gas constant =287 J / (Kg·K), thermodynamic temperature T=t+273.15 (t is the temperature in Celsius)

[0061] The density of dry air can be calculated using the ideal gas law:

[0062]

[0063] The gas constant for dry air is Rv = 461.5 J / (kg·K).

[0064] Saturated vapor pressure It varies with temperature, and can be calculated using the Antoine equation:

[0065]

[0066] The relative humidity of the air is Ф, and the actual partial pressure of water vapor is:

[0067] =Ф·

[0068] The density of water vapor can be calculated using the ideal gas law:

[0069]

[0070] The common temperature range in tea gardens is t=15℃-30℃, and the relative humidity is Ф=30%-90%.

[0071] Operating Condition 1: Low temperature and low humidity (t=15℃, Ф=30%)

[0072] Saturated vapor pressure:

[0073]

[0074] Actual vapor pressure: =0.3 =519.9

[0075] Partial pressure of dry air: =101325-519.9=100805.1

[0076] Thermodynamic temperature: =15 + 273.15 = 288.15K

[0077] Dry air density:

[0078]

[0079] Water vapor density:

[0080]

[0081] Moist air density:

[0082] The flight resistance of the tea green leafhopper under low temperature and low humidity conditions.

[0083]

[0084] Under low temperature and low humidity conditions The capture conditions are still met.

[0085] Operating Condition 2: High temperature and high humidity (t=30℃, Ф=90%)

[0086] Saturated vapor pressure:

[0087]

[0088] Actual vapor pressure: =0.9 =3825

[0089] Partial pressure of dry air: =101325-3825=97500

[0090] Thermodynamic temperature: =30 + 273.15 = 303.15K

[0091] Dry air density:

[0092]

[0093] Water vapor density:

[0094]

[0095] Moist air density:

[0096] The flight resistance of the tea green leafhopper under low temperature and low humidity conditions.

[0097]

[0098] Under low temperature and high humidity conditions The capture conditions are still met.

[0099] Under the combined effects of natural wind and extreme temperature and humidity, the capture criterion of "drag > lift" is always satisfied.

[0100] Example 3: Simulation / Experiment / Usage

[0101] A 3D steady-state simulation model was built using Ansys Fluent 24.2.0, and a customized simulation scheme was developed for the flow field response characteristics of small insects.

[0102] (1) Adaptability of simulation model and algorithm

[0103] Turbulence model: The standard k-epsilon model is selected to adapt to high Reynolds number flow in the air intake channel (air velocity at the inlet is 20 m / s, channel diameter is 15 cm, Reynolds number Re≈2.1 × 10⁻⁶). With Re > 4000, the flow is in a highly turbulent state, which verifies the rationality of using the k-epsilon turbulence model and accurately captures the interference of turbulent eddies on the flight of small insects;

[0104] Wall treatment: Standard wall functions are used to effectively simulate the flow near the wall (small insects often fly close to the wall), ensuring the accuracy of near-wall flow velocity calculation;

[0105] Solution Algorithm: The SIMPLE algorithm couples pressure and velocity. The second-order discretization of the pressure term improves the accuracy of the pressure gradient calculation, and the second-order upwind discretization of the momentum term captures sudden changes in flow velocity, ensuring that no flow field details are lost.

[0106] (2) Mesh and Convergence

[0107] Grid strategy: The total number of cells is over 4.89 million. Local densification is carried out in key areas of the flow path of small insects, such as channel corners, the edges of the guide plate, and the inlet annular area (minimum grid size 0.1mm), covering the size scale of small insects (1-5mm).

[0108] Mesh quality: Minimum orthogonal quality 0.0762, within the acceptable range for engineering, ensuring computational stability; maximum aspect ratio 51.96, concentrated in the straight sections of the channel, with aspect ratio <10 in key flow field regions to avoid pseudo-diffusion errors;

[0109] Convergence verification: After 328 iterations, the residual of the continuity equation decreased to 0.000996 (far below the convergence threshold of 0.001), and the residuals of the velocity components (U, V, W) were all < 3 × 10⁻⁶. The residuals of turbulence parameters (k, ε) are <0.001, the flow field calculation reaches stable convergence, and the results are reliable.

[0110] (3) Flow field characteristics: verifying the reliability of insect trapping

[0111] Global flow velocity stability: by Figure 4 It can be seen that the overall flow velocity in the channel is ≥15m / s. Even in the narrowest section of the channel, the flow velocity remains stable at 16~18m / s. There are no low-velocity zones (flow velocity ≥16m / s) near corners and guide vanes.

[0112] The pressure gradient decreases uniformly: from Figure 5 It can be seen that the inlet pressure is -50Pa and the outlet pressure is -100Pa, forming a uniformly decreasing pressure gradient along the channel axis. The "push" at the front end guides the insects to move towards the insect collection chamber, while the "suction" at the rear end forcibly captures them and prevents them from being trapped.

[0113] Low turbulence intensity: due to Figure 6 It can be seen that the turbulence intensity inside the channel is ≤5%, which is much lower than the turbulence intensity of natural wind (10~20%), thus avoiding the insects' alertness caused by the turbulent flow field;

[0114] No eddy current interference: Figure 7 The streamlined trajectory transitions smoothly, without backflow zones or vortices, preventing small insects from being swept back into the inlet by the vortex.

[0115] The simulation performed well overall. It adopted appropriate settings such as 3D, pressure basis, and standard k-epsilon turbulence model. The material properties were consistent with the actual air parameters, the boundary conditions were logically consistent, the solver was reasonably configured, and all residuals reached the convergence criteria after 328 iterations. The overall settings were standardized and the convergence state was good, which can provide a valid reference for the design of fluid channels in the device.

[0116] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A fluent-based phototactic small-volume insect-catching channel, comprising a plastic outer shell (1), the outer shell (1) being divided into an inlet section, an arc-shaped middle section, and an outlet section, the inlet section being an open structure, and the outlet section being connected to an insect-collecting device, characterized in that, Also includes: The inlet section includes an air inlet (2) opened on the lower surface of the device housing (1), and four equally spaced guide vanes (3) are fixedly installed on the inner side of the air inlet (2), and a central cylinder (4) is fixedly installed in the middle position of the inner side of the air inlet (2), and an axial flow fan (401) is installed on the upper end of the central cylinder (4). The arc-shaped middle section includes a single-curvature arc surface (7) disposed on the back of the device housing (1); The outlet section includes an outlet baffle (10) that is fixedly installed on the upper end of the device housing (1). An air knife (8) is fixedly installed in the middle of the inner wall of the single curvature arc surface (7), and the radius of the single curvature arc surface (7) is 25cm, and the central angle corresponding to the single curvature arc surface (7) is 60°. The air knife (8) is embedded in the center of the single curvature arc surface (7).

2. The phototactic small-volume insect trapping channel based on fluent according to claim 1, characterized in that: An LED insect-attracting lamp (6) is fixedly installed at the bottom of the central cylinder (4), and an integrated sensor module (5) is fixedly installed on the inner wall of the guide plate (3), and the sensor module (5) includes a wind speed sensor and an infrared sensor.

3. The phototactic small-volume insect trapping channel based on Fluent according to claim 1, characterized in that: The device housing (1) is fixedly mounted on the top of a 4G transceiver module (9), and a high-speed camera (11) is fixedly mounted on the top of the outlet baffle (10).

4. The phototactic small-volume insect trapping channel based on fluent according to claim 1, characterized in that: The angle between the guide vane (3) and the horizontal axis is 15°, forming an expansion structure.

5. A fluent-based phototactic small-volume insect trapping channel according to claim 1, characterized in that: The outlet baffle (10) forms an 8° contraction angle with the vertical axis, gradually converging the airflow and forming a strong suction zone at the end in front of the outlet.

6. The fluent-based phototactic small-volume insect trapping channel according to claim 2, characterized in that: The LED insect-attracting lamp (6) uses low-power LED beads, and the LED insect-attracting lamp (6) and the central cylinder (4) adopt a plug-in installation structure.

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