A multifunctional electromagnetic launching device and method for wind tunnel model launching test

Abstract

A multifunctional electromagnetic deployment device and method for wind tunnel model deployment tests belongs to the field of dynamic testing technology for model wind tunnels. It solves the problems of slow deployment speed and poor repeatability in existing technologies. Key technical points: The top surface of the bracket is fixedly connected to the test model. Two openings are made at the bottom of the bracket, each containing an electromagnet. Two electromagnet cover plates are installed at the bottom of the bracket corresponding to the two electromagnets. A limiter track is provided between the two openings. The model head section, front magnetic section, middle section, rear magnetic section, and tail section are sequentially spliced ​​and fixed. Mounting grooves are provided on both the front and rear magnetic sections. A neodymium magnet with a countersunk hole is placed in the mounting groove closest to the bracket at the top. This invention realizes the connection of the test model before separation, free deployment of the deployed object, and deployment of the object with initial velocity, ensuring close contact between the deployed objects and simulating the real separation process.

Description

Technical Field

[0001] This invention relates to the field of dynamic testing technology for model wind tunnels, specifically to a multifunctional electromagnetic launching device and method for wind tunnel model launching tests. Background Technology

[0002] When an aircraft releases external objects, the separated body passes through an extremely complex turbulent flow field and experiences a strong unsteady and nonlinear aerodynamic environment. The aerodynamic changes during this process are extremely drastic and may produce unpredictable collision risks. In the early days, flight tests were the main method, which was costly and risky. With the advancement of wind tunnel equipment and testing technology, wind tunnel model release tests have gradually become a standard procedure and play an extremely important role in the design and development cycle.

[0003] Wind tunnel drop tests are dynamic aerodynamic tests conducted in a wind tunnel. Their core purpose is to verify the safety and reliability of aircraft external attachment ejection, stage separation, or various payload delivery processes. They provide intuitive, accurate, and highly reliable test data for aircraft development, and are a crucial technical approach to ensuring flight safety, shortening development cycles, and reducing R&D costs and flight test risks. Wind tunnel drop separation tests are based on similarity theory, reproducing the physical process of separation through scaled-down model tests. Depending on the delivery method, they can be divided into gravity delivery and delivery with initial velocity, both implemented by a wind tunnel delivery mechanism.

[0004] Existing wind tunnel model deployment test equipment lacks precise control over initial velocity, initial angular velocity, and initial attitude angle, resulting in large ejection and release errors. Ground calibration results deviate significantly from actual wind tunnel flow conditions, leading to poor test repeatability and consistency, directly impacting data reliability. Scaled-down models struggle to achieve full-scale Reynolds number similarity, and boundary layer and separation characteristics deviate from actual flight performance. Most are custom-designed, requiring redesign and manufacturing for different models, resulting in long cycles and high costs. They are difficult to adapt to multiple sizes, configurations, and separation modes. Wind tunnel operation is energy-intensive, has long preparation cycles, and results in high costs and low frequency of single tests.

[0005] Therefore, there is an urgent need to propose a multifunctional electromagnetic delivery device and method for wind tunnel model delivery tests to solve the problems of slow delivery speed and poor repeatability in the existing technology. Summary of the Invention

[0006] In view of the above facts, in order to solve the problems of slow deployment speed and poor repeatability in the prior art, the present invention designs a multifunctional electromagnetic deployment device and method for wind tunnel model deployment tests.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] Option 1: A multifunctional electromagnetic delivery device for wind tunnel model delivery tests, comprising a hanger, an electromagnet, an electromagnet cover plate, a limiter track, and a delivery model;

[0009] The top surface of the bracket is fixedly connected to the test model. The bottom of the bracket has two openings, and an electromagnet is installed inside each of the two openings. Two electromagnet cover plates are installed at the bottom of the bracket, corresponding to the two electromagnets respectively. A limiter track is set between the two openings.

[0010] The delivery model includes a head section, a front magnetic section, a neodymium magnet with a countersunk hole, a middle section, a rear magnetic section, a tail section, and a limiter.

[0011] The head section, front magnetic section, middle section, rear magnetic section, and tail section of the model are sequentially spliced ​​and fixed. The front magnetic section and the rear magnetic section of the model are provided with mounting slots. The mounting slot closest to the bracket at the top is filled with a neodymium magnet with a countersunk hole, and the other mounting slots are filled with counterweights. The limiter is set on the middle section of the model, and the ball bearings on the limiter are in rolling contact with the limiter track.

[0012] The bracket is equipped with an electromagnet circuit.

[0013] The electromagnet is magnetically attracted to the neodymium magnet with a countersunk hole.

[0014] More specifically: a set of electronic switch groups is placed on each of the left and right sides of the electromagnet circuit. Each set of electronic switch groups has two electronic switches arranged vertically. The electromagnet is placed between the two sets of electronic switch groups. The electromagnet and each set of electronic switch groups form two half-bridges. The freewheeling diode is connected in parallel with the electronic switch in the opposite direction.

[0015] Furthermore, the end faces of the head section, middle section, and tail section of the model are all provided with slots, and the end faces of the front magnetic section and rear magnetic section of the model are all provided with buckles, which are spliced ​​and fixed with the slots.

[0016] Furthermore, the electromagnet is a square electromagnet.

[0017] Furthermore, the electromagnet cover plate is provided with four screw holes, which are used to install it on the bottom of the bracket.

[0018] Furthermore, the electronic switch is a power transistor.

[0019] Furthermore, the bracket is a box-type aluminum alloy structure.

[0020] Furthermore, the two electromagnets are controlled by a series circuit, and the coils of each electromagnet are wound in the same direction.

[0021] Option 2: A multifunctional electromagnetic delivery method for wind tunnel model delivery tests, implemented using a multifunctional electromagnetic delivery device for wind tunnel model delivery tests as described in Option 1, specifically as follows:

[0022] S1: The freewheeling diode D1 is connected in reverse parallel with the power transistor Q1. When it is turned on, the upper node of the power transistor Q1 is driven to the same voltage as the battery supply voltage V. bat Equal potential levels;

[0023] The freewheeling diode D2 is connected in reverse parallel with the power transistor Q2. When it is turned on, it drives the lower node of the power transistor Q2 to a potential level equal to the reference ground.

[0024] The freewheeling diode D3 is connected in reverse parallel with the power transistor Q3. When it is turned on, it drives the upper node of the power transistor Q3 to the same voltage as the battery supply voltage V. bat Equal potential levels;

[0025] The freewheeling diode D4 is connected in reverse parallel with the power transistor Q4. When it is turned on, it drives the lower node of the power transistor Q4 to a potential level equal to the reference ground.

[0026] S2: When the electromagnet circuit is energized, power transistors Q1 and Q4 are turned on. Current flows from the positive terminal of the power supply through power transistor Q1 from left to right through the electromagnet, and returns to the negative terminal of the power supply through power transistor Q4. This causes the two electromagnets to generate magnetic force and attract and fix the object model with the neodymium magnet with the sink hole. The relative position is adjusted by the limiter track and the limiter until the object model is in the correct position.

[0027] S3: Begin the wind tunnel model gravity drop test;

[0028] S31: At the start of the test, the electromagnet circuit is in a connected state;

[0029] S32: When the electromagnet circuit is closed, the magnetic force disappears after the power is cut off, and the object model falls downwards under the action of gravity.

[0030] S4: Begin wind tunnel initial velocity drop test;

[0031] S41: At the start of the test, the electromagnet circuit is in a connected state;

[0032] S42: Change the current in the electromagnet circuit to the opposite direction, power transistors Q2 and Q3 are turned on, and the current flows through the electromagnet from right to left. At this time, the direction of the electromagnet's magnetic poles is instantly reversed, generating a repulsive force, and the object model is launched downwards with initial velocity.

[0033] Furthermore, in S4, the initial velocity of the launch is changed by altering the magnitude of the current in the electromagnet circuit.

[0034] The beneficial effects of this invention are as follows:

[0035] 1. This invention realizes the connection of the experimental model before separation, the free release of the objects, and the release of the objects with initial velocity, ensuring close contact between the objects and simulating the real separation process.

[0036] 2. This invention can ensure that there is no external interference during the delivery process, and the magnitude and direction of the repulsive force are stable and reliable when the object is delivered with initial velocity, which is easy to calibrate.

[0037] 3. This invention achieves both gravity-based and initial velocity-based deployment functions, with controllable force direction and deployment speed, and a large envelope range.

[0038] 4. This invention relates to a system with few components, a simple structure, and the ability to achieve rapid installation. Attached Figure Description

[0039] Figure 1 This is a front view of the dispensing device in this invention;

[0040] Figure 2 This is a schematic diagram of the circuit principle of the present invention.

[0041] In the diagram: 1-Hanging bracket, 2-Electromagnet, 3-Screw hole, 4-Electromagnet cover plate, 6-Limiter track, 7-Model head section, 8-Model front magnetic section, 9-Neodymium magnet with countersunk hole, 10-Snap fastener, 11-Mounting slot, 12-Model middle section, 13-Model rear magnetic section, 14-Slot, 15-Model tail section, 16-Limiter. Detailed Implementation

[0042] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0043] The terms "set up," "connect," and "fix" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0044] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0045] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0046] Example 1: Reference Figure 1 This embodiment describes a multifunctional electromagnetic launching device for wind tunnel model launching tests, comprising a hanger 1, an electromagnet 2, an electromagnet cover plate 4, a limiter track 6, and a launching model.

[0047] The top surface of the bracket 1 is fixedly connected to the test model. The bottom of the bracket 1 has two openings, and an electromagnet 2 is installed inside each of the two openings. Two electromagnet cover plates 4 are installed at the bottom of the bracket 1, corresponding to the two electromagnets 2 respectively. A limiter track 6 is set between the two openings.

[0048] The delivery model includes a head section 7, a front magnetic section 8, a neodymium magnet with a countersunk hole 9, a middle section 12, a rear magnetic section 13, a tail section 15, and a limiter 16.

[0049] The head section 7, front magnetic section 8, middle section 12, rear magnetic section 13, and tail section 15 of the model are sequentially spliced ​​and fixed. The front magnetic section 8 and the rear magnetic section 13 of the model are both provided with mounting slots 11. The mounting slot 11 closest to the bracket 1 at the top is filled with a neodymium magnet 9 with a countersunk hole to provide magnetic force for the object model. The other mounting slots 11 are filled with counterweights to balance the weight and rotational inertia distribution of the object model. The limiter 16 is set on the middle section 12 of the model. The ball bearings on the limiter 16 roll in contact with the limiter track 6 to determine the installation position of the object model.

[0050] The bracket 1 is equipped with an electromagnet circuit inside.

[0051] The electromagnet 2 is magnetically attracted to the neodymium magnet 9 with a countersunk hole.

[0052] More specifically: On each side of the electromagnet circuit, a set of electronic switch groups is placed. Each set of electronic switch groups has two electronic switches arranged vertically. Electromagnet 2 is placed between the two sets of electronic switch groups. Electromagnet 2 and each set of electronic switch groups form two half-bridges. The freewheeling diode is connected in parallel with the electronic switch in reverse. When the load generates a reverse electromotive force, it provides a freewheeling circuit for the current and protects the electronic switch from being broken down by reverse voltage.

[0053] More specifically: the electronic switch is a power transistor.

[0054] More specifically: the bracket 1 is a box-type aluminum alloy structure.

[0055] More specifically: the end faces of the head section 7, the middle section 12, and the tail section 15 of the model are all provided with slots 14, and the end faces of the front magnetic section 8 and the rear magnetic section 13 of the model are all provided with buckles 10, which are spliced ​​and fixed with the slots 14.

[0056] More specifically: the electromagnet 2 is a square electromagnet.

[0057] More specifically: the two electromagnets 2 are controlled by a series circuit, and the coils of each electromagnet 2 are wound in the same direction, and their magnetic poles are the same after being energized.

[0058] More specifically: the electromagnet cover plate 4 is provided with four screw holes 3, which are installed at the bottom of the bracket 1 by screws.

[0059] Example 2: A multifunctional electromagnetic delivery method for wind tunnel model delivery tests, implemented using a multifunctional electromagnetic delivery device for wind tunnel model delivery tests as described in Example 1, specifically as follows:

[0060] S1: The freewheeling diode D1 is connected in reverse parallel with the power transistor Q1. When it is turned on, the upper node of the power transistor Q1 is driven to the same voltage as the battery supply voltage V. bat Equal potential levels;

[0061] The freewheeling diode D2 is connected in reverse parallel with the power transistor Q2. When it is turned on, it drives the lower node of the power transistor Q2 to a potential level equal to the reference ground.

[0062] The freewheeling diode D3 is connected in reverse parallel with the power transistor Q3. When it is turned on, it drives the upper node of the power transistor Q3 to the same voltage as the battery supply voltage V. bat Equal potential levels;

[0063] The freewheeling diode D4 is connected in reverse parallel with the power transistor Q4. When it is turned on, it drives the lower node of the power transistor Q4 to a potential level equal to the reference ground.

[0064] S2: When the electromagnet circuit is energized, power transistors Q1 and Q4 are turned on. Current flows from the positive terminal of the power supply through power transistor Q1 from left to right through electromagnet 2, and returns to the negative terminal of the power supply through power transistor Q4. This causes the two electromagnets 2 to generate magnetic force and attract and fix the object model with the neodymium magnet 9 with the countersunk hole. The relative position is adjusted by limiter track 6 and limiter 16 until the object model is in the correct position.

[0065] S3: Begin the wind tunnel model gravity drop test;

[0066] S31: At the start of the test, the electromagnet circuit is in a connected state;

[0067] S32: When the electromagnet circuit is closed, the magnetic force disappears after the power is cut off, and the object model falls downwards under the action of gravity.

[0068] S4: Begin wind tunnel initial velocity drop test;

[0069] S41: At the start of the test, the electromagnet circuit is in a connected state;

[0070] S42: Change the current in the electromagnet circuit to the opposite direction, power transistors Q2 and Q3 are turned on, and the current flows from right to left through electromagnet 2. At this time, the magnetic pole direction of electromagnet 2 is reversed instantly, generating a repulsive force, and the object model is launched downward with initial velocity.

[0071] More specifically: In S4, the initial velocity of the launch is changed by altering the magnitude of the current in the electromagnet circuit.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; as long as there is no structural conflict, the various features in the specific embodiments disclosed in this application can be combined with each other in any way, and will not cause the substance of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

[0073] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A multifunctional electromagnetic delivery device for wind tunnel model delivery tests, characterized in that, Includes a hanger (1), an electromagnet (2), an electromagnet cover plate (4), a limiter track (6), and a model of the object to be placed; The top surface of the bracket (1) is fixedly connected to the test model. The bottom of the bracket (1) has two openings, and electromagnets (2) are installed inside the two openings. Two electromagnet cover plates (4) are installed at the bottom of the bracket (1) respectively corresponding to the two electromagnets (2). A limiter track (6) is set between the two openings. The object model includes a head section (7), a front magnetic section (8), a neodymium magnet with a countersunk hole (9), a middle section (12), a rear magnetic section (13), a tail section (15), and a limiter (16). The head section (7), front magnetic section (8), middle section (12), rear magnetic section (13), and tail section (15) of the model are sequentially spliced ​​and fixed. The front magnetic section (8) and the rear magnetic section (13) of the model are provided with mounting slots (11). The mounting slot (11) closest to the bracket (1) at the top is filled with a neodymium magnet (9) with a countersunk hole. The other mounting slots (11) are filled with counterweights. The limiter (16) is set on the middle section (12) of the model. The ball on the limiter (16) rolls in contact with the limiter track (6). The bracket (1) is equipped with an electromagnet circuit inside; The electromagnet (2) is magnetically attracted to the neodymium magnet (9) with a countersunk hole.

2. The multifunctional electromagnetic delivery device for wind tunnel model delivery testing according to claim 1, characterized in that, On the left and right sides of the electromagnet circuit, a set of electronic switch groups are placed. Each set of electronic switch groups has two electronic switches arranged vertically. The electromagnet (2) is placed between the two sets of electronic switch groups. The electromagnet (2) and each set of electronic switch groups form two half bridges. The freewheeling diode is connected in parallel with the electronic switch in the opposite direction.

3. The multifunctional electromagnetic launching device for wind tunnel model launching tests according to claim 1, characterized in that, The end faces of the head section (7), middle section (12), and tail section (15) of the model are all provided with slots (14), and the end faces of the front magnetic section (8) and rear magnetic section (13) of the model are all provided with buckles (10). The buckles (10) are spliced ​​and fixed with the slots (14).

4. The multifunctional electromagnetic launching device for wind tunnel model launching tests according to claim 1, characterized in that, The electromagnet (2) is a square electromagnet.

5. A multifunctional electromagnetic launching device for wind tunnel model launching tests according to claim 1, characterized in that, The electromagnet cover plate (4) is provided with four screw holes (3), which are installed at the bottom of the bracket (1) by screws.

6. A multifunctional electromagnetic delivery device for wind tunnel model delivery testing according to claim 2, characterized in that, The electronic switch is a power transistor.

7. A multifunctional electromagnetic launching device for wind tunnel model launching tests according to claim 1, characterized in that, The bracket (1) is a box-type aluminum alloy structure.

8. A multifunctional electromagnetic launching device for wind tunnel model launching tests according to claim 1, characterized in that, The two electromagnets (2) are controlled by a series circuit, and the coils of each electromagnet (2) are wound in the same direction.

9. A multifunctional electromagnetic delivery method for wind tunnel model delivery tests, implemented using the multifunctional electromagnetic delivery device for wind tunnel model delivery tests as described in claim 6, characterized in that, Specifically: S1: The freewheeling diode D1 is connected in reverse parallel with the power transistor Q1. When it is turned on, the upper node of the power transistor Q1 is driven to the same voltage as the battery supply voltage V. bat Equal potential levels; The freewheeling diode D2 is connected in reverse parallel with the power transistor Q2. When it is turned on, it drives the lower node of the power transistor Q2 to a potential level equal to the reference ground. The freewheeling diode D3 is connected in reverse parallel with the power transistor Q3. When it is turned on, it drives the upper node of the power transistor Q3 to the same voltage as the battery supply voltage V. bat Equal potential levels; The freewheeling diode D4 is connected in reverse parallel with the power transistor Q4. When it is turned on, it drives the lower node of the power transistor Q4 to a potential level equal to the reference ground. S2: When the electromagnet circuit is energized, power transistors Q1 and Q4 are turned on. Current flows from the positive terminal of the power supply through power transistor Q1 from left to right through the electromagnet (2), and returns to the negative terminal of the power supply through power transistor Q4, causing the two electromagnets (2) to generate magnetic force and attract and fix the object model with the neodymium magnet (9) with the sink hole. The relative position is adjusted by the limiter track (6) and limiter (16) until the object model is in the correct position. S3: Begin the wind tunnel model gravity drop test; S31: At the start of the test, the electromagnet circuit is in a connected state; S32: When the electromagnet circuit is closed, the magnetic force disappears after the power is cut off, and the object model falls downwards under the action of gravity. S4: Begin wind tunnel initial velocity drop test; S41: At the start of the test, the electromagnet circuit is in a connected state; S42: Change the current in the electromagnet circuit to the opposite direction, power transistors Q2 and Q3 are turned on, and the current passes through the electromagnet (2) from right to left. At this time, the magnetic pole direction of the electromagnet (2) is reversed instantly, generating a repulsive force, and the object model is launched downward with initial velocity.

10. A multifunctional electromagnetic delivery method for wind tunnel model delivery tests according to claim 9, characterized in that, In step S4, the initial velocity of the launch is changed by altering the current in the electromagnet circuit.

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