A flutter generator for wind tunnel testing

Abstract

This invention discloses a model flutter generator for wind tunnel testing, comprising: a linkage system, a support system, and a servo system; the support system serves as the basic support structure for the model flutter generator, and the components of the servo system are assembled and installed through the support system; the linkage system is connected to the support system; the test model is mounted on the model flutter generator via the linkage system. The purpose of this invention is to enable the test model to flutter at a specified frequency and amplitude during wind tunnel testing.

Description

Technical Field

[0001] This invention belongs to the field of experimental aerodynamics technology, and particularly relates to a flutter generator for wind tunnel testing. Background Technology

[0002] For hypersonic vehicles, such as winged missiles and gliders, flutter is an unavoidable and significant factor affecting flight safety during actual flight. When flutter occurs, the aerodynamic and thermal dynamics of the vehicle exhibit unsteady changes over time, placing higher demands on the vehicle's control and thermal protection. Effectively simulating the flutter state in ground tests to study the unsteady aerodynamic and thermal dynamics under flutter conditions is crucial for analyzing the flutter aerodynamic performance of aircraft.

[0003] Currently, designing rigid models and using excitation devices to induce vibration, while measuring the time-varying signals of pressure and temperature distribution in a wind tunnel environment, is a relatively practical and feasible method for verifying unsteady aerodynamic force calculations. This method can provide a basis for flutter analysis in aircraft model design. However, the lack of high-precision model flutter generators and the difficulty in adjusting frequency and amplitude lead to insufficient accuracy in simulating aircraft flutter. The accuracy of aerodynamic characteristic tests under flutter conditions is generally lower than that of foreign methods, gradually becoming a technical bottleneck in unsteady testing under flutter conditions. Summary of the Invention

[0004] The technical problem solved by the present invention is to overcome the shortcomings of the prior art and provide a model flutter generating device for wind tunnel testing, which aims to enable the test model to flutter at a specified frequency and amplitude during wind tunnel testing.

[0005] To address the aforementioned technical problems, this invention discloses a model flutter generator for wind tunnel testing, comprising: a linkage system, a support system, and a servo system;

[0006] The support system serves as the basic support structure for the model flutter generator. Components in the servo system are installed and assembled through the support system, and the linkage system is connected to the support system. The test model is mounted on the model flutter generator through the linkage system.

[0007] In the aforementioned model flutter generator for wind tunnel testing, the support system includes: a base, linear guide rails, a servo motor mounting base, a test platform, and side plates;

[0008] The servo motor mounting base and side plate are welded to the test platform as a single unit;

[0009] The base is fixed to the side plate;

[0010] The base is provided with a base boss and a guide rail mounting groove; the linear guide rail is fixed in the guide rail mounting groove by screws.

[0011] In the aforementioned model flutter generator for wind tunnel testing, the servo system includes: a servo motor, a reducer, and an eccentric wheel;

[0012] The servo motor, reducer, and eccentric wheel are connected in sequence to form a drive mechanism; the servo motor drives the eccentric wheel to rotate at a specified speed through the reducer.

[0013] The servo motor and reducer are mounted and fixed to the servo motor mounting base via flanges.

[0014] In the above-mentioned model flutter generator for wind tunnel testing, the linkage system includes: a stationary link, a moving link, a connector, a plunger rod, a plunger, a spring, pin A, pin B, and pin C;

[0015] One end of the stationary connecting rod is fixed to the base with screws, located at the end of the base away from the test platform. The other end of the stationary connecting rod is hinged to one end of the moving connecting rod by pin A. Both the stationary and moving connecting rods are semi-cylindrical, forming a complete cylinder after being connected.

[0016] The other end of the moving connecting rod is hinged to one end of the plunger rod via pin B; the other end of the plunger rod is hinged to one end of the plunger via pin C.

[0017] The spring is mounted on the plunger rod, with the two ends of the spring connected to the base boss and the plunger, respectively. Under the tension of the spring, the other end of the plunger is pressed against the eccentric wheel.

[0018] The plunger is located inside the linear guide and can only move in a straight line within the track of the linear guide;

[0019] The connector is installed at one end of the moving link.

[0020] In the aforementioned flutter generator for wind tunnel testing, the test model is fixed to the connector.

[0021] In the aforementioned flutter generator for wind tunnel testing, the plunger rod is positioned to pass through a through hole on the base boss.

[0022] The aforementioned flutter generator for wind tunnel testing also includes a fairing; wherein the fairing is mounted and fixed to the base and side plate.

[0023] In the aforementioned flutter generator for wind tunnel testing, the fairing is wedge-shaped.

[0024] In the aforementioned model flutter generator used for wind tunnel testing, two linear guide rails are installed face-to-face, with the plunger clamped between the rails to reduce space occupancy.

[0025] In the aforementioned flutter generator for wind tunnel testing, the test model and the connector, and the connector and the moving link are connected by cylindrical mating and positioned by pins passing through the axis in the circumferential direction.

[0026] The present invention has the following advantages:

[0027] (1) This invention discloses a model flutter generator for wind tunnel testing, which can simulate the flutter of an aircraft in flight state in a ground wind tunnel test environment, including different vibration frequencies and different amplitudes, and realize the aerodynamic and thermal research of the aircraft flutter state in a ground wind tunnel test environment.

[0028] (2) This invention discloses a model flutter generator for wind tunnel testing. The control system is simple. By controlling the output of the motor and reducer, the different vibration frequencies of the test model can be converted in a single test without increasing the cost of wind tunnel testing.

[0029] (3) The present invention discloses a model flutter generator for wind tunnel testing. The plunger used can achieve line contact with the eccentric wheel of the motor. By replacing the eccentric wheel of different sizes, the different amplitudes of the model can be easily changed.

[0030] (4) This invention discloses a model flutter generator for wind tunnel testing. It has a compact structure, is easy to control, makes full use of the space between the wind tunnel test model and the test section, and can be designed in a similar series according to different test models and loads, thereby meeting the needs of different tests and having strong applicability. Attached Figure Description

[0031] Figure 1 This is a perspective view of a model flutter generator for wind tunnel testing according to an embodiment of the present invention;

[0032] Figure 2 This is a perspective view of a model flutter generator (excluding fairing) for wind tunnel testing according to an embodiment of the present invention;

[0033] Figure 3 This is a front view of a model flutter generator (excluding fairing) for wind tunnel testing according to an embodiment of the present invention;

[0034] Figure 4 This is a top view of a model flutter generator (excluding fairing) for wind tunnel testing according to an embodiment of the present invention.

[0035] Figure 5 for Figure 3 AA section view

[0036] Figure 6 for Figure 4 BB cross-sectional view

[0037] Figure 7 This is a schematic diagram of a linkage system according to an embodiment of the present invention;

[0038] Figure 8 This is a schematic diagram of the structure of a support system according to an embodiment of the present invention. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments disclosed in the present invention will be described in further detail below with reference to the accompanying drawings.

[0040] One of the core ideas of this invention is to provide a model flutter generator for wind tunnel testing, addressing the research needs of unsteady aerodynamic parameters of aircraft under flutter conditions in current ground wind tunnel testing environments. This device is installed in the wind tunnel test section and connected to the test model, and can generate flutter in the model according to specified different frequencies and amplitudes, forming an effective simulation of the flutter state of the aircraft during actual flight. It can also effectively measure various signals such as pressure and temperature distribution of the aircraft under flutter conditions, providing support for ground flutter research of aircraft.

[0041] like Figures 1-6 In this embodiment, the model flutter generator for wind tunnel testing includes: a linkage system 2, a support system 4, and a servo system 5. The support system 4 serves as the basic support structure for the model flutter generator. The components of the servo system 5 are assembled and installed via the support system 4. The linkage system 2 is connected to the support system 4. The test model 1 is mounted on the model flutter generator via the linkage system 2.

[0042] In this embodiment, as Figure 8 The support system 4 may specifically include: a base 41, a linear guide rail 42, a servo motor mounting base 43, a test platform 44, and a side plate 45. The servo motor mounting base 43 and the side plate 45 are welded together with the test platform 44; the base 41 is mounted and fixed on the side plate 45; the base 41 is provided with a base boss 411 and a guide rail mounting groove 412; the linear guide rail 42 is mounted and fixed in the guide rail mounting groove 412 by screws.

[0043] In this embodiment, as Figure 2 The servo system 5 may specifically include: a servo motor 51, a reducer 52, and an eccentric wheel 53. The servo motor 51, the reducer 52, and the eccentric wheel 53 are connected in sequence to form a drive mechanism; the servo motor 51 drives the eccentric wheel 53 to rotate at a specified speed through the reducer 52; the servo motor 51 and the reducer 52 are mounted and fixed on the servo motor mounting base 43 through a flange.

[0044] In this embodiment, as Figure 7 The linkage system 2 specifically includes: a stationary connecting rod 21, a moving connecting rod 22, a connector 23, a plunger rod 24, a plunger 25, a spring 26, pins A71, B72, and C73. One end of the stationary connecting rod 21 is fixed to the base 41 with screws, located at the end of the base 41 furthest from the test platform 44. The other end of the stationary connecting rod 21 is hinged to one end of the moving connecting rod 22 via pin A71. Both the stationary connecting rod 21 and the moving connecting rod 22 are semi-cylindrical, forming a complete cylinder after docking to reduce interference with the tail flow field during wind tunnel testing of the test model 1. The plunger rod 24 passes through a through hole on the base boss 411. One end of the plunger rod 24 is hinged to the other end of the moving connecting rod 22 via pin B72, and the other end of the plunger rod 24 is hinged to one end of the plunger 25 via pin C73. Spring 26 is mounted on plunger rod 24. Both ends of spring 26 are connected to base boss 411 and plunger 25 respectively. Under the tension of spring 26, the other end of plunger 25 is pressed against eccentric wheel 53. Two linear guides 42 are mounted face-to-face, clamping plunger 25 between them to reduce space occupancy; that is, plunger 25 is located within linear guides 42 and can only move linearly within the tracks of linear guides 42. Connector 23 is mounted on one end of moving connecting rod 22. Test model 1 is fixed to connector 23.

[0045] Preferably, the test model 1 and the connector 23, and the connector 23 and the moving link 22 are connected by cylindrical mating and positioned by a pin passing through the axis in the circumferential direction.

[0046] In this embodiment, as Figure 1 The flutter generator for wind tunnel testing may further include a fairing 3. The fairing 3 is mounted and fixed on the base 41 and the side plate 45. The fairing 3 is wedge-shaped to reduce the drag of the flutter generator during wind tunnel testing and to reduce interference with the tail flow field of the test model 1.

[0047] In this embodiment, the working principle of the model flutter generator for wind tunnel testing is as follows:

[0048] During operation, the servo motor drives the eccentric wheel to rotate via the reducer. The eccentric wheel pushes the plunger to translate along the linear guide rail. The plunger's translational velocity is sinusoidal. The plunger rod drives the connecting rod to oscillate sinusoidally, thus achieving the sinusoidal oscillation of the projectile. Specifically: When the servo motor 51 drives the eccentric wheel 53 to rotate via the reducer 52, the eccentric wheel 53 pushes the plunger 25 to move within the linear guide rail 42. Under the action of the spring 26, the plunger 25 remains in contact with the eccentric wheel 53, achieving reciprocating linear motion. The up-and-down movement of the plunger 25 causes the plunger rod 24 to oscillate cyclically. The plunger rod 24 further drives the connecting rod 22 to oscillate cyclically, further driving the test model 1, which is fixed to the connecting rod 22 via the connector 23, to oscillate up and down cyclically. It is known that the final oscillation mode of the test model 1 is sinusoidal.

[0049] When it is necessary to increase the amplitude of test model 1 in wind tunnel testing, the eccentricity of the eccentric wheel 53 can be increased, which increases the reciprocating stroke of the plunger 25 and further increases the amplitude of test model 1 through the plunger rod 24 and the moving connecting rod 22. Conversely, when it is necessary to decrease the amplitude of test model 1, the eccentricity of the eccentric wheel 53 can be decreased.

[0050] When the wind tunnel test requires increasing the vibration frequency of the model, the rotational speed of the servo motor 51 can be increased, which increases the reciprocating speed of the plunger 25 and further increases the vibration frequency of the model through the plunger rod 24 and the connecting rod 22. Conversely, when it is necessary to decrease the vibration frequency of the test model 1, the rotational speed of the servo motor 51 can be decreased.

[0051] When this model flutter generator is applied to the flutter test of other models, the dimensions of the static connecting rod 21, the moving connecting rod 22 and the connector 23 can be changed accordingly to ensure that a certain flow field space is left at the tail after the model is installed, and other structures do not need to be modified.

[0052] In summary, this invention discloses a model flutter generator for wind tunnel testing, which can generate flutter in test models at different frequencies and amplitudes during wind tunnel testing. Furthermore, the flutter generator has high applicability, requires minimal modification of components for flutter testing of different test models, establishes a high-precision simulation capability for flutter testing in wind tunnels, and provides conditions for flutter research in aircraft ground testing.

[0053] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

[0054] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A flutter generator for a model used in wind tunnel testing, characterized in that, include: Linkage system (2), support system (4) and servo system (5); The support system (4) serves as the basic support structure for the model flutter generator. The components of the servo system (5) are installed and assembled through the support system (4). The linkage system (2) is connected to the support system (4). The test model (1) is installed on the model flutter generator through the linkage system (2). The support system (4) includes: a base (41), a linear guide rail (42), a servo motor mounting base (43), a test platform (44), and a side plate (45); wherein, the servo motor mounting base (43) and the side plate (45) are welded together with the test platform (44); the base (41) is fixedly mounted on the side plate (45); the base (41) is provided with a base boss (411) and a guide rail mounting groove (412); the linear guide rail (42) is fixedly mounted in the guide rail mounting groove (412) by screws; The servo system (5) includes: a servo motor (51), a reducer (52), and an eccentric wheel (53); wherein the servo motor (51), the reducer (52), and the eccentric wheel (53) are connected in sequence to form a drive mechanism; the servo motor (51) drives the eccentric wheel (53) to rotate at a specified speed through the reducer (52); the servo motor (51) and the reducer (52) are mounted and fixed on the servo motor mounting base (43) through a flange; The linkage system (2) includes: a stationary connecting rod (21), a movable connecting rod (22), a connector (23), a plunger rod (24), a plunger (25), a spring (26), pin A (71), pin B (72), and pin C (73); wherein, one end of the stationary connecting rod (21) is fixed to the base (41) by screws, located at the end of the base (41) away from the test platform (44), and the other end of the stationary connecting rod (21) is hinged to one end of the movable connecting rod (22) by pin A (71); both the stationary connecting rod (21) and the movable connecting rod (22) are semi-cylindrical, forming a complete cylinder after docking; the other end of the movable connecting rod (22) is connected to the plunger One end of the rod (24) is hinged to the pin B (72); the other end of the plunger rod (24) is hinged to one end of the plunger (25) through the pin C (73); the spring (26) is installed on the plunger rod (24), and the two ends of the spring (26) are connected to the base boss (411) and the plunger (25) respectively. Under the tension of the spring (26), the other end of the plunger (25) is pressed against the eccentric wheel (53); the plunger (25) is located in the linear guide (42) and can only move in a straight line in the track of the linear guide (42); the connector (23) is installed at one end of the moving connecting rod (22); the test model (1) is fixed to the connector (23).

2. The flutter generator for wind tunnel testing according to claim 1, characterized in that, The plunger rod (24) passes through a through hole on the base boss (411).

3. The flutter generator for wind tunnel testing according to claim 1, characterized in that, Also includes: Fairing (3); wherein the fairing (3) is mounted and fixed on the base (41) and the side plate (45).

4. The flutter generator for wind tunnel testing according to claim 3, characterized in that, The fairing (3) is wedge-shaped.

5. The flutter generator for wind tunnel testing according to claim 1, characterized in that, Two linear guides (42) are installed face to face, clamping the plunger (25) between the guides to reduce the space occupied.

6. The flutter generator for wind tunnel testing according to claim 1, characterized in that, The experimental model (1) and the connector (23), and the connector (23) and the moving link (22) are connected by cylindrical mating and positioned by a pin passing through the circumference around the axis.

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