Self-excited oscillation hot jet bionic deicing device and design method

Abstract

This invention discloses a self-excited oscillating thermal jet biomimetic de-icing device and its design method. The device includes at least one self-excited oscillating thermal jet unit, which includes multiple jet exciters for de-icing and jet connectors connected to the jet exciters via pipelines. Each jet exciter has a mixing chamber, a first inlet nozzle, and a first outlet throat, the first outlet throat being used to output an oscillating thermal jet. The jet exciter also has a feedback channel connecting the mixing chamber and the inlet nozzle. This device can perform de-icing operations with low energy consumption and low damage, while also providing aerodynamic gain. It also avoids contact damage to the substrate or coating of the object being treated caused by mechanical de-icing. Furthermore, its overall structure is simple and easy to use, allowing for rapid installation on complex curved surfaces such as wind turbine blades, aircraft wings, and UAV rotors. It operates automatically after being connected to an air source.

Description

Technical Field

[0001] This invention relates to the field of de-icing technology for complex curved surfaces, specifically to a self-excited oscillating thermal jet biomimetic de-icing device and its design method. Background Technology

[0002] Low temperatures, freezing rain, wet snow, and cloud icing can cause icing on the surfaces of wind turbine blades, aircraft airfoils, UAV rotors, power transmission lines, rail transit overhead contact lines, and polar engineering equipment. Icing not only alters airfoil geometry and surface roughness but also increases mass eccentricity and unsteady loads, leading to deterioration of lift-drag characteristics, reduced output power, increased structural fatigue, and a heightened risk of ice fall. IEA Wind TCP Task 19 has released guidelines for wind turbine icing detection, icing loss assessment, and ice fall risk assessment for cold-climate wind farms, indicating that wind power icing has become a significant engineering issue in the development, operation, maintenance, and safety assessment of wind power in cold climates.

[0003] Public research indicates that icing causes wind turbine power curves to deviate from clean blade conditions. Icing-induced power generation losses at severely iced sites can reach over 20% of annual power generation; icing loss methods also consider a significant downward shift in the power curve under icing conditions as an important criterion for identifying icing losses.

[0004] Traditional mechanical de-icing relies on vibration, knocking, scraping, or manual removal, resulting in long downtime, low automation, and potential damage to anti-corrosion coatings and aerodynamic profiles. Traditional thermal melting / electric / gas-heated de-icing relies on continuous heating, which, while providing a direct response, leads to rapid heat loss, long energy transfer paths on long blades, and may cause localized overheating and secondary icing. Passive anti-icing coatings can reduce ice adhesion, but their active removal capability is insufficient against thick ice or continuous freezing rain, and their wear resistance, corrosion resistance, and long-term retention still need to be verified.

[0005] In addition, existing de-icing methods are prone to leaving some areas untreated or having jet blind spots, making it difficult to form a continuous coverage in the leading edge main icing area; moreover, if the de-icing device does not take into account the curved aerodynamic shape, it may increase local resistance or introduce new flow separation; although some passive biomimetic structures can improve aerodynamic performance, they lack active de-icing capabilities. Summary of the Invention

[0006] The purpose of this invention is to address the problems existing in the prior art by providing a self-excited oscillating thermal jet biomimetic de-icing device and its design method.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, a self-excited oscillating thermal jet biomimetic de-icing device is provided, comprising at least one self-excited oscillating thermal jet unit, wherein the self-excited oscillating thermal jet unit includes a plurality of jet actuators for de-icing, and a jet connector connected to the jet actuators via a pipeline; the jet actuator has a mixing chamber inside, one end of the mixing chamber has a first inlet nozzle connected to the pipeline, and the other end of the mixing chamber has a first outlet throat for outputting an oscillating thermal jet; the jet actuator also has a feedback channel connecting the mixing chamber and the first inlet nozzle.

[0008] This biomimetic de-icing device, based on the self-excited oscillating thermal jet unit, can perform de-icing operations with low energy consumption and low damage, while also providing aerodynamic gain. This de-icing method does not require additional heat energy or auxiliary heating devices, and can also avoid contact damage to the substrate or coating of the object being treated caused by mechanical de-icing. Moreover, the overall structure is simple and easy to use, and can be quickly installed on complex curved surfaces such as wind turbine blades, aircraft wings, and UAV rotors. It operates automatically after being connected to an air source.

[0009] Furthermore, the jet actuator includes an actuator body, one end of which is provided with an inlet pipe joint for connecting to the pipeline, and the inlet pipe joint is provided with an airflow channel with a gradually decreasing cross-sectional size, the end of which is the first inlet nozzle; the other end of the actuator body is provided with an outlet channel with a gradually increasing cross-sectional size, and the first outlet throat is located at the intersection of the outlet channel and the mixing chamber.

[0010] Furthermore, the maximum cross-sectional dimension of the outlet channel is greater than the cross-sectional dimension of the first inlet nozzle, and the effective jet angle of a single outlet channel is 20-30°.

[0011] Furthermore, the jet exciter has a cavity inside, in which a pair of modified fluids are provided, forming a mixing chamber between the pair of modified fluids, and forming a feedback channel between the pair of modified fluids and the inner wall of the cavity; the upper opening between the pair of modified fluids corresponds to the first inlet nozzle, and the lower opening corresponds to the first outlet throat, with the size of the lower opening being larger than the size of the upper opening.

[0012] Furthermore, the jet connector includes an air source connector and a branch connection portion connected to the air source connector. The branch connection portion is provided with multiple outlet branches below it. Each outlet branch is connected to one of the jet exciters through the pipeline. The air source connector is used to connect to the air supply component.

[0013] Furthermore, the air source connector is provided with a funnel-shaped air intake channel, the branch connection is provided with a dispersion chamber, a second inlet nozzle is provided at the connection between the air intake channel and the dispersion chamber, and a second outlet throat is provided at the connection between the dispersion chamber and each of the outlet branch pipes.

[0014] Furthermore, multiple self-excited oscillating thermal jet units are disposed on the object requiring de-icing, and the jet exciters are arranged at intervals on the outer surface of the object.

[0015] Furthermore, the objects to be processed include at least icing structures such as wind turbine blades, aircraft wing surfaces, UAV rotors, propellers, power transmission lines, and communication towers.

[0016] Furthermore, when the object being processed is a wind turbine blade, the jet exciter is arranged at the biomimetic protrusion within the 0.2R to 0.8R region of the wind turbine blade, and the installation reference position is determined based on the equivalent biomimetic function, where R is the rotation radius of the wind turbine blade.

[0017] Secondly, a design method for a self-excited oscillating thermal jet biomimetic de-icing device is provided, the design method comprising the following steps: Fabricate several self-excited oscillating hot jet units, including multiple jet exciters and jet connectors; A de-icing simulation experiment was conducted on the self-excited oscillating hot jet unit to verify its de-icing effect. Select a suitable object to be processed, perform biomimetic processing on the object, and determine the installation reference point arranged along the surface of the object; then install the jet exciter at the installation reference point, install the jet connector on the object, connect the pipeline and connect the air source.

[0018] Preferably, the wind turbine blades are selected as the objects to be de-iced, and the wind turbine blades are biomimetically treated based on the irregular protrusions at the leading edge of the humpback whale flippers to determine the biomimetic protrusions arranged along the surface of the wind turbine blades. The shape equation of the biomimetic bump is expressed as follows: , In the formula, A is the amplitude of the bionic bump, E is the amplitude attenuation index, N is the number of bionic bumps, and x is the coordinate position of the bionic bump in the spanwise direction of the leading edge of the wind turbine blade, which is used to determine the installation reference point of each jet exciter. Install the jet exciter at the mounting reference point, install the jet connector on the fan blade, connect the pipeline and connect the air source.

[0019] The leading-edge protrusion of humpback whale flippers has been shown to delay stall, induce vortices, and improve post-stall aerodynamic characteristics at high angles of attack. Introducing this biomimetic leading-edge protrusion into wind turbine blades or airfoil structures can improve local separation, reduce aerodynamic losses, and provide a morphological basis for integrating de-icing actuators with blade aerodynamic structures.

[0020] The self-excited oscillating thermal jet actuator is a fluid oscillator without moving parts. After the airflow enters the mixing chamber, it adheres to one side wall due to the Coanda effect. The feedback channel guides the local pressure disturbance back to the jet root, causing the main jet to periodically switch its adhesion to the wall and form a spatial sweep output. Compared with a unidirectional fixed nozzle, the oscillating thermal jet can expand the coverage area and enhance boundary layer disturbance under the same air supply conditions, making it suitable for integration with hot air de-icing, flow control, and biomimetic structures.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Based on the self-excited oscillating thermal jet unit, this biomimetic de-icing device can perform de-icing operations with low energy consumption and low damage, while also providing aerodynamic gain. This de-icing method does not require additional heat energy or auxiliary heating devices, and can also avoid contact damage to the substrate or coating of the object being treated by mechanical de-icing. Moreover, the overall structure is simple and easy to use, and can be quickly installed on complex curved surfaces such as wind turbine blades, aircraft wings, and UAV rotors, and operates automatically after connecting to the air source; 2. The self-excited oscillating thermal jet unit, through the jet exciter and the jet connector, has a great degree of installation freedom and applicability. The jet exciter can be installed on objects with different airfoils, curvatures, and sizes according to design requirements, and the jet connector is not limited by the structural shape of the object being treated, and has strong adaptability; 3. Multiple jet exciters are distributed to effectively cover the icing area, resulting in a large de-icing range and good effect; 4. The jet exciter is internally equipped with It features a unique mixing chamber, a first inlet nozzle, and a first outlet throat, allowing airflow to be injected into the mixing chamber. The airflow mixes within the mixing chamber, forming a flow field that alters pressure and velocity. The airflow is then ejected from the first outlet throat, creating an oscillating thermal jet. Compared to direct jet de-icing, this method offers superior de-icing performance, completing de-icing in a shorter time. Furthermore, the mixing chamber incorporates a feedback channel, creating a self-feedback closed-loop internal flow field that automatically adjusts the jet frequency and intensity. This eliminates the need for external electrical control, enabling the formation of a continuous, stable, and periodic self-excited oscillating thermal jet. The entire process requires no electrical control or external drive; it can achieve self-sustaining oscillation solely based on the pressure difference of the flow field itself. 6. When the optimal array arrangement of six self-excited oscillating hot jet units is adopted, full-coverage de-icing can be achieved in the 0.2R~0.8R region at the front edge of complex curved surfaces, with no obvious blind spots. The ice-breaking response is rapid; thin ice (≤5mm) can be completely removed within 30s, and medium-thickness ice layers (10~20mm) can achieve interface softening and overall peeling within 60~120s. The de-icing speed is more than 50% faster than conventional hot blowing and mechanical de-icing. Attached Figure Description

[0022] Figure 1 This is an overall schematic diagram of a self-excited oscillating thermal jet biomimetic de-icing device according to the present invention; Figure 2 This is a schematic diagram of the internal structure of the jet exciter of the present invention; Figure 3 This is a schematic diagram of the internal three-dimensional structure of the jet exciter of the present invention; Figure 4 This is a schematic diagram of the airflow inside the jet exciter of the present invention; Figure 5 This is a schematic diagram of the internal structure of the jet connector of the present invention; Figure 6This is a schematic diagram of the jet exciter installed on the wind turbine blade according to the present invention; Figure 7 This is a schematic diagram of the distribution of test points at the outlet plane of the jet exciter in Example 2; Figure 8 This is a schematic diagram of the normalized velocity distribution at the inlet of the jet exciter in Example 2; Figure 9 This is a schematic diagram showing the simulation results of the wind turbine blades in Example 3; Figure 10 This is a schematic diagram illustrating the effect of the number of jet exciters on the wind turbine power in Example 3; Figure 11 This is a simulation diagram of the jet process in Example 3; In the figure: 1. Jet exciter; 101. Exciter body; 102. Inlet pipe connector; 103. Modified fluid; 2. Jet connector; 201. Air source connector; 202. Flow splitter connection; 203. Outlet branch pipe; 3. Air supply component; 4. Mixing chamber; 5. First inlet nozzle; 6. First outlet throat; 7. Feedback channel; 8. Airflow channel; 9. Outlet channel; 10. Oscillating hot jet; 11. Inlet channel; 12. Second inlet nozzle; 13. Second outlet throat; 14. Fan blades. Detailed Implementation

[0023] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely 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.

[0024] In the description of this invention, it should be noted that the terms "middle," "upper," "lower," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] Example 1: A self-excited oscillating thermal jet biomimetic de-icing device is provided, such as... Figures 1-5As shown, it includes at least one self-excited oscillating thermal jet unit, which includes multiple jet actuators 1 for de-icing, and a jet connector 2 connected to the jet actuators 1 via a pipeline; the jet actuator 1 has a mixing chamber 4 inside, one end of the mixing chamber 4 has a first inlet nozzle 5 connected to the pipeline, and the other end of the mixing chamber 4 has a first outlet throat 6 for outputting an oscillating thermal jet 10; the jet actuator 1 also has a feedback channel 7 connecting the mixing chamber 4 and the first inlet nozzle 5.

[0026] This biomimetic de-icing device, based on the self-excited oscillating thermal jet unit, can perform de-icing operations with low energy consumption and low damage, while also providing aerodynamic gain. This de-icing method does not require additional heat energy or auxiliary heating devices, and can also avoid contact damage to the substrate or coating of the object being treated caused by mechanical de-icing. Moreover, the overall structure is simple and easy to use, and can be quickly installed on complex curved surfaces such as wind turbine blades, aircraft wings, and UAV rotors. It operates automatically after being connected to an air source.

[0027] The self-excited oscillating thermal jet unit, through the arrangement of the jet exciter 1 and the jet connector 2, has a great degree of installation freedom and applicability. The jet exciter 1 can be installed on processing objects with different airfoils, curvatures and sizes according to design requirements, and the jet connector 2 is not limited by the structural shape of the processing object, and has strong adaptability.

[0028] The jet connector 2 can connect to the air source and divide the air source into multiple paths to supply each jet exciter 1. The multiple jet exciters 1 are distributed in a dispersed manner, which can effectively cover the icing area, and the de-icing range is large and the effect is good.

[0029] The jet exciter 1 is internally equipped with a unique mixing chamber 4, a first inlet nozzle 5, and a first outlet throat 6. It can inject airflow into the mixing chamber 4, where the airflow mixes to form a flow field, changing the pressure and velocity, before exiting from the first outlet throat 6 to form an oscillating thermal jet. Compared to direct jet de-icing, it has a better de-icing effect and can complete de-icing in a shorter time. Furthermore, the mixing chamber 4 is equipped with a feedback channel 7, creating a self-feedback closed loop in the internal flow field. This automatically adjusts the jet frequency and intensity, achieving continuous, stable, and periodic self-excited oscillating thermal jet formation without external electrical control. The entire process requires no electrical control or external drive; it relies solely on the pressure difference within the flow field to achieve self-sustaining oscillation, significantly expanding the jet coverage area compared to traditional jet technologies.

[0030] Furthermore, the jet exciter 1 includes an exciter body 101, one end of which is provided with an inlet pipe joint 102 connected to the pipeline, and the inlet pipe joint 102 is provided with an airflow channel 8 with a gradually decreasing cross-sectional size, the end of which is the first inlet nozzle 5; the other end of the exciter body 101 is provided with an outlet channel 9 with a gradually increasing cross-sectional size, and the first outlet throat 6 is located at the intersection of the outlet channel 9 and the mixing chamber 4.

[0031] The inlet pipe connector 102 can be used to connect the pipeline. The airflow channel 8 adopts a gradually decreasing cross-sectional size and is equipped with the first inlet nozzle 5, which can accelerate the airflow injected into the mixing chamber and reduce the pressure. It can also draw in airflow by utilizing the low-pressure area at the smallest cross-section of the first inlet nozzle 5. It can also improve the airflow concentration and outlet wind speed, while reducing the air consumption.

[0032] The outlet channel 9 adopts a gradually increasing cross-sectional size, and the first outlet throat 6 is set at the point where the cross-section is the smallest. This can slow down the outlet airflow and increase the pressure, stabilize the flow and reduce noise, which is conducive to forming an oscillating hot jet that meets the de-icing requirements.

[0033] Furthermore, the maximum cross-sectional dimension of the outlet channel 9 is larger than the cross-sectional dimension of the first inlet nozzle 5, and the effective jet angle of a single outlet channel 9 is 20-30°. This ensures a stable jet while guaranteeing the de-icing effect. An excessively large jet angle can easily lead to air loss control, while a small jet angle can affect the de-icing effect.

[0034] Furthermore, the jet exciter 1 has a cavity inside, in which a pair of modified fluids 103 are provided, and the mixing chamber 4 is formed between the pair of modified fluids 103. The feedback channel 7 is formed between the pair of modified fluids 103 and the inner wall of the cavity. The upper opening between the pair of modified fluids 103 corresponds to the first inlet nozzle 5, and the lower opening corresponds to the first outlet throat 6. The size of the lower opening is larger than the size of the upper opening.

[0035] The above configuration allows for a more open mixing chamber 4 between the pair of modified fluids 103, enabling the airflow to form a flow field. The feedback channels 7 on both sides allow some of the airflow to be drawn in and re-enter the mixing chamber along with the airflow from the inlet nozzle, achieving a self-feedback closed loop, which is beneficial for self-adjusting the oscillating hot jet.

[0036] Furthermore, the jet connector 2 includes an air source connector 201 and a diversion connection part 202 connected to the air source connector 201. The diversion connection part 202 is provided with a plurality of outlet branch pipes 203 below it. Each outlet branch pipe 203 is connected to one of the jet exciters 1 through the pipeline. The air source connector 201 is used to connect to the air supply component 3.

[0037] Gas is supplied to the gas source connector through the gas supply component 3. The gas enters the lower branch connection 202 and can be distributed to each of the outlet branch pipes 203. The gas is then supplied to each of the jet exciters 1 through the pipeline. Each jet connector 2 can be provided with 5-8 outlet branch pipes, and the multiple outlet branch pipes 203 are distributed at equal intervals. The gas supply component 3 can be an air compressor, air pump, or hot air blower, etc., which can provide hot air.

[0038] Furthermore, the air source connector 201 is provided with a funnel-shaped air inlet channel 11, the branch connection part 202 is provided with a dispersion chamber, the air inlet channel 11 is provided with a second inlet nozzle 12 at the connection between the dispersion chamber and the dispersion chamber, and the dispersion chamber is provided with a second outlet throat 13 at the connection between the dispersion chamber and each of the outlet branch pipes 203.

[0039] The funnel-shaped air intake channel 11, together with the second inlet nozzle 12, can also adjust the airflow pressure and velocity. The second outlet throat 13 ensures the pressure and velocity of the airflow entering the pipeline.

[0040] Furthermore, multiple self-excited oscillating thermal jet units are disposed on the object requiring de-icing, and the jet exciters are arranged at intervals on the outer surface of the object.

[0041] Furthermore, the objects to be processed include at least icing structures such as wind turbine blades, aircraft wing surfaces, UAV rotors, propellers, power transmission lines, and communication towers.

[0042] Furthermore, when the object of processing is the wind turbine blade 14, such as Figure 6 As shown, the jet exciter 1 array is arranged at the biomimetic protrusions in the 0.2R to 0.8R region of the wind turbine blade 14. The installation reference position is determined according to the equivalent biomimetic function, where R is the rotation radius of the wind turbine blade.

[0043] Through biomimetic design, biomimetic protrusions are evenly distributed in the 0.2R~0.8R region of the leading edge of the blade, and the arrangement is based on the following: (1) Aerodynamic and icing coupling characteristics: 0.2R~0.8R is the main working area of ​​the wind turbine blades, with the highest risk of airflow separation, the greatest probability of icing and the thickest icing, and is the core section for de-icing and flow control; (2) Structural and installation constraints: The root part of the wind turbine blade (0~0.2R section) is thick and has a sharp twist angle, which is not convenient for modular unit installation and jet action; the tip part of the wind turbine blade (0.8R~1R section) has a high linear velocity and a slender structure, and dense arrangement can easily cause aerodynamic noise and structural fatigue. (3) Maximize efficiency: The 0.2R~0.8R range covers about 60% of the blade's span, which can achieve the optimal balance between aerodynamic gain and de-icing coverage of the entire blade with the minimum installation amount.

[0044] With the above configuration, the self-excited oscillating thermal jet unit can function as both a de-icing actuator and a biomimetic protrusion on the leading edge of a blade / airfoil to participate in flow control. Multiple jet units are connected in parallel or in parallel sections to the same main chamber via pipelines, achieving large-area, low-damage de-icing. Hot air is used to form a water film at the ice-substrate interface and reduce adhesion strength, and then the ice layer is peeled off using oscillating thermal jet shearing, pressure disturbance, external airflow, or centrifugal force.

[0045] Example 2: A design method for a self-excited oscillating thermal jet biomimetic de-icing device is provided.

[0046] The design method includes the following steps: (1) Fabricate several self-excited oscillating hot jet units, including multiple jet exciters and jet connectors; (2) A de-icing simulation experiment was conducted on the self-excited oscillating hot jet unit to verify the de-icing effect of the self-excited oscillating hot jet unit; (3) Select a suitable object to be processed, perform biomimetic processing on the object to be processed, and determine the installation reference point arranged along the surface of the object to be processed; then install the jet exciter at the installation reference point, install the jet connector on the object to be processed, connect the pipeline and connect the air source.

[0047] Preferably, the wind turbine blades are selected as the object of de-icing treatment, and the wind turbine blades are biomimeticly treated based on the irregular protrusions at the leading edge of the humpback whale flippers to determine the biomimetic protrusions arranged along the surface of the wind turbine blades.

[0048] The irregular protrusions on the leading edge of the humpback whale's flipper can slow down airflow at high angles of attack. Their shape is highly similar to that of a wind turbine blade. Drawing on this biomimetic characteristic, the distribution of these protrusions was simulated in an experiment.

[0049] The shape equation of the biomimetic bump is expressed as follows: , In the formula, A is the amplitude of the bionic bump, E is the amplitude attenuation index, N is the number of bionic bumps, and x is the coordinate position of the bionic bump in the spanwise direction of the leading edge of the wind turbine blade, which is used to determine the installation reference point of each jet exciter. Based on the above shape equation, the coordinates when the cosine function is at its minimum value are taken as the placement position of the protrusion. In this embodiment, the bionic protrusion is evenly distributed in the 0.2R~0.8R region of the leading edge of the blade, and set at 6 positions. Install the jet exciter at the mounting reference point, install the jet connector on the fan blade, connect the pipeline and connect the air source.

[0050] The above design achieves the synergistic effect of "inspired aerodynamic optimization + active de-icing with oscillating hot jet + hot air interface de-adhesion" without significantly altering the original blade structure. This solves the problem of limited heating coverage and difficulty in covering the main icing area of ​​the blade. It also features low energy consumption, high practicality, and minimal mechanical damage.

[0051] Furthermore, the theoretical design and parameter calculation of the jet actuator were carried out, and the matching design of the actuator geometry, layout scheme, and key flow field parameters were completed. The dimensional parameters of the jet actuator are shown in the figure. The length of the actuator body is 12mm, the width is 10.2mm, the wall thickness at the inlet of the airflow channel in its inlet pipe joint is 1.2mm, the diameter of the first inlet nozzle is about 1.2mm, and the outlet dimension of the outlet channel is 1.5mm.

[0052] Using the following data acquisition system and calculation model, the uncertainties of the main aerodynamic parameters, the total pressure loss at the outlet, and the airflow angle (jet angle) are calculated.

[0053] The data acquisition system consists of a five-hole probe, a Pitot tube, and a digital pressure scanning system. The probe is precisely positioned using a coordinate displacement system, and pressure data is acquired via a PSI-9116 sensor at a sampling frequency of 50Hz, with the average value taken over 6 seconds. Figure 7 As shown, the distribution of measuring points at the outlet test section is illustrated: denser measuring points are used in the near-wall region of the inlet measuring surface, while 24 (circumferential) × 32 (spanwise) measuring points are set at the outlet surface. The density of measuring points is increased in the boundary layer, wake region, and high-loss region to improve the resolution of flow characteristics. Figure 8 The distribution of the normalized inlet velocity at the inlet cross section is shown (u is the local velocity, u0 is the velocity in the blade).

[0054] , , In the formula, Indicates the total pressure loss coefficient. This indicates the average static pressure at the inlet. This indicates the average total pressure of the imported goods. This represents the average total pressure at the outlet mass, where F is a given aerodynamic parameter. , , Variables , and At a confidence level of 95%, the uncertainties of the main aerodynamic parameters in this fabrication can be obtained using the above formula. The calculated uncertainty of the total outlet pressure loss is ±1.97%, and the uncertainty of the airflow angle is ±1°.

[0055] Example 3: This example presents two de-icing simulation experiments from Example 2.

[0056] The first method involves verifying the effectiveness through simulation experiments. 3D models of Cases 1 to 5 were built using SolidWorks software, and process simulations were then performed in Fluent software based on these models. The simulation results are as follows: Figure 9 As shown.

[0057] The torque results from the simulation process were recorded, thereby obtaining and recording the wind turbine power for each case, as shown in Table 1 and... Figure 10 As shown, it can be seen that the appropriate placement of the self-excited oscillating hot jet device can effectively improve the overall power of the wind turbine, which reflects that the aerodynamic performance of the blades can be effectively improved under the modification of bionic principles. However, when there are too many self-excited oscillating hot jet units, the power will drop significantly, the mutual interference between jets will intensify, and the overall efficiency of the device will be affected. The highest power increase rate is 3.7%.

[0058] Table 1: Wind turbine power output under different experimental schemes

[0059] Combination Figure 11 As shown, the short line indicates the instantaneous velocity direction of the fluid at that location. The self-excitation module automatically adjusts the jet frequency and intensity through the internal flow field self-feedback closed loop. It can form a continuous, stable, and periodic self-excited oscillating thermal jet without external electrical control. The entire process does not require electrical control or external drive, and can achieve self-sustaining oscillation by relying solely on the pressure difference of the flow field itself. Compared with traditional jet technology, it greatly expands the jet coverage range.

[0060] The second method is to verify the de-icing effect through physical experiments.

[0061] Multiple jet exciters were arranged at intervals on an acrylic plate, and the jet connector and air supply component were connected. The acrylic plate was covered with frozen ice. The experimental ice temperature was set to -30 to -40°C to match actual application conditions. A jet de-icing experiment was conducted using hot air. The measured effective jet angle was 23°, the maximum jet distance was 90 cm, and a significant de-icing effect was observed after 1 minute and 36 seconds of operation.

[0062] Multiple de-icing performance tests were conducted on the device under low-temperature environments and simulated icing conditions. The results showed that, under ambient temperatures of -5 to -10℃ and ice thicknesses of 10 to 20 mm, the effective ice-breaking distance of a single-module self-excited oscillating hot jet unit could reach 15 to 20 cm, forming a continuous, penetrating crack zone along the blade airfoil direction. With the optimal array arrangement of six self-excited oscillating hot jet units, full-coverage de-icing could be achieved in the 0.2R to 0.8R region at the leading edge, with no significant blind spots. The ice-breaking response was rapid; thin ice (≤5 mm) could be removed within 30 seconds, and medium-thickness ice layers (10 to 20 mm) could achieve interface softening and overall peeling within 60 to 120 seconds. The de-icing speed was more than 50% faster than conventional hot blowing and mechanical de-icing methods.

[0063] The device operates stably in a high-humidity and cold environment from -20 to 0℃, with jet frequency, outlet wind speed and temperature fluctuations of less than 5%. The non-contact de-icing method will not damage the substrate and surface coating, and it has strong adaptability and high reliability.

[0064] 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 self-excited oscillating thermal jet biomimetic de-icing device, characterized in that, The device includes at least one self-excited oscillating thermal jet unit, which comprises multiple jet actuators for de-icing and a jet connector connected to the jet actuators via a pipeline. The jet actuators have a mixing chamber inside, with a first inlet nozzle at one end connected to the pipeline, and a first outlet throat at the other end for outputting an oscillating thermal jet. The jet actuators also include a feedback channel connecting the mixing chamber and the first inlet nozzle.

2. The self-excited oscillating thermal jet biomimetic de-icing device according to claim 1, characterized in that, The jet actuator includes an actuator body, one end of which is provided with an inlet pipe joint for connecting to the pipeline, and the inlet pipe joint is provided with an airflow channel with a gradually decreasing cross-sectional size, the end of which is the first inlet nozzle; the other end of the actuator body is provided with an outlet channel with a gradually increasing cross-sectional size, and the first outlet throat is located at the intersection of the outlet channel and the mixing chamber.

3. The self-excited oscillating thermal jet biomimetic de-icing device according to claim 1, characterized in that, The maximum cross-sectional dimension of the outlet channel is greater than the cross-sectional dimension of the first inlet nozzle, and the effective jet angle of a single outlet channel is 20-30°.

4. The self-excited oscillating thermal jet biomimetic de-icing device according to claim 1, characterized in that, The jet exciter has an internal cavity, in which a pair of modified fluids are disposed. The pair of modified fluids form the mixing cavity, and the pair of modified fluids and the inner wall of the cavity form the feedback channel. The upper opening between the two fluids corresponds to the first inlet nozzle, and the lower opening corresponds to the first outlet throat, wherein the size of the lower opening is larger than the size of the upper opening.

5. The self-excited oscillating thermal jet biomimetic de-icing device according to claim 1, characterized in that, The jet connector includes an air source connector and a branch connection part connected to the air source connector. Multiple outlet branches are provided below the branch connection part. Each outlet branch is connected to a jet exciter through the pipeline. The air source connector is used to connect to the air supply component.

6. The self-excited oscillating thermal jet biomimetic de-icing device according to claim 5, characterized in that, The air source connector is provided with a funnel-shaped air intake channel, the branch connection is provided with a dispersion chamber, the air intake channel and the dispersion chamber are provided with a second inlet nozzle, and the dispersion chamber and each of the outlet branch pipes are provided with a second outlet throat.

7. The self-excited oscillating thermal jet biomimetic de-icing device according to claim 1, characterized in that, Multiple self-excited oscillating thermal jet units are disposed on the object requiring de-icing, and the jet exciters are arranged at intervals on the outer surface of the object.

8. The self-excited oscillating thermal jet biomimetic de-icing device according to claim 7, characterized in that, The objects to be processed include, at a minimum, ice-covered structures such as wind turbine blades, aircraft wing surfaces, UAV rotors, propellers, power transmission lines, and communication towers.

9. The self-excited oscillating thermal jet biomimetic de-icing device according to claim 7, characterized in that, When the object to be processed is a wind turbine blade, the jet exciter is arranged at the biomimetic protrusion in the 0.2R to 0.8R region of the wind turbine blade, and the installation reference position is determined according to the equivalent biomimetic function, where R is the rotation radius of the wind turbine blade.

10. The design method of the self-excited oscillating thermal jet biomimetic de-icing device according to any one of claims 1 to 9, characterized in that, The design method includes the following steps: Fabricate several self-excited oscillating hot jet units, including multiple jet exciters and jet connectors; A de-icing simulation experiment was conducted on the self-excited oscillating hot jet unit to verify its de-icing effect. The wind turbine blades were selected as the objects to be de-iced. Based on the irregular protrusions on the leading edge of the humpback whale flippers, the wind turbine blades were biomimeticized to determine the biomimetic protrusions arranged along the surface of the wind turbine blades. The shape equation of the biomimetic bump is expressed as follows: ， In the formula, A is the amplitude of the bionic bump, E is the amplitude attenuation index, N is the number of bionic bumps, and x is the coordinate position of the bionic bump in the spanwise direction of the leading edge of the wind turbine blade, which is used to determine the installation reference point of each jet exciter. Install the jet exciter at the mounting reference point, install the jet connector on the fan blade, connect the pipeline and connect the air source.

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