Aircraft aerodynamic characteristic measurement test device and test method for simulating air inlet flow

Abstract

The invention belongs to the technical field of wind tunnel tests, and discloses a test device and a test method for measuring aerodynamic characteristics of an aircraft by simulating air inlet flow. A ventilation model of the test device is installed on the upper portion of a tail boom support through a balance corrugated pipe and a ventilation supporting rod, a variable sideslip angle device is installed between the rear section of the tail boom support and an installation platform, a flowmeter, an ejector and other measuring devices are fixed to the installation platform, and the rear end of the installation platform is fixedly connected with a bent knife mechanism of a wind tunnel. The sideslip angle changing device changes the sideslip angle of the ventilation model. The test method comprises the steps of wind tunnel test preparation; performing a wind tunnel test; and processing test data. According to the invention, a supporting mode of'tail boom + lifting 'is adopted, so that perfect combination of a test system and a supporting system is realized; the hollow telescopic sleeve with the spherical hinges at the two ends is adopted, compensation of airflow pipeline length and angle changes caused by sideslip angle deflection is achieved, a solution is provided for accurate simulation of large continuous high-speed wind tunnel air inlet flow, and engineering practical value is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of wind tunnel tests, and in particular relates to an aircraft aerodynamic characteristic measurement test device and a test method for simulating intake flow. Background Art

[0002] The air inlet is an important part of the aircraft power system. With the development of science and technology, the aircraft's external dimensions are getting larger and larger. Most large aircraft generally adopt the body / propulsion system integrated design technology. The air inlet has become an inseparable part of the aircraft fuselage, and the integration degree between the front fuselage and the air inlet is getting higher and higher. Some aircraft also have dynamically changing air inlet geometry. The intake flow of the air inlet has a great influence on the aerodynamic characteristics of the aircraft. The fine design of the aircraft urgently needs to obtain the influence of the intake flow on the aerodynamic characteristics of the whole aircraft.

[0003] Wind tunnel testing is the most direct and reliable technical means to obtain the aerodynamic characteristics of aircraft, and can quickly, systematically and scientifically obtain the aerodynamic characteristics of aircraft. At present, the aerodynamic characteristics measurement test of ventilation models carried out in 1-meter to 2-meter wind tunnels generally adopts the support method of "rod balance + tail strut". Due to the limitation of the scale and space of the ventilation model, supersonic flow occurs inside some ventilation models (the balance and struts occupy a certain space, and the flow space inside the ventilation model is limited), which has a certain impact on the accuracy of the aerodynamic characteristics measurement data of the aircraft. In addition, flow regulation often adopts the method of presetting flow rings in the flow channel inside the ventilation model, which makes it difficult to achieve refined simulation of flow and flow inside the inlet. In addition, although some 1-meter to 2-meter wind tunnels have developed aircraft ventilation dynamometric wind tunnel test technology by combining the two test devices and test methods of dynamometric wind tunnel test and inlet test, and adopted a "tail support + belly support" support scheme, and solved the flow simulation problem in the full flow range of the inlet through the intervention of flow meters and ejectors, there is still a certain support interference; moreover, for large aircraft, excessive reduction will cause serious simulation distortion. At the same time, because the ventilation model is too small, it is impossible to simulate the aerodynamic characteristics of large aircraft in the dynamic process of changing the geometric shape of the inlet.

[0004] Large-scale continuous wind tunnels above 4 meters provide a good foundation for the development of aerodynamic characteristics measurement test technology for aircraft that accurately simulates the intake flow; the ventilation model of large-scale continuous wind tunnels above 4 meters is relatively large, and motors can be installed on the ventilation model to simulate the dynamic process of the variable geometry of the intake duct and obtain the aerodynamic characteristics in the dynamic process. However, in large-scale continuous wind tunnels, the ventilation model and support system are both large in scale, the load increases exponentially, and the airflow pipeline system increases exponentially. The support of the ventilation model, flowmeter and ejector faces great difficulties. At the same time, large-scale continuous wind tunnels also require the realization of continuous adjustment of the sideslip angle (the connection change of the angle of attack can be achieved through the scimitar mechanism of the wind tunnel), and the establishment of related technologies is very difficult; in addition, how to reduce the interference of the downstream flow of the intake duct on the upstream flow and the interference of the support system on the surface flow of the ventilation model are also urgent problems to be solved.

[0005] Currently, there is an urgent need to develop an aircraft aerodynamic characteristics measurement test device and test method that simulates intake flow. Summary of the invention

[0006] One technical problem to be solved by the present invention is to provide an aircraft aerodynamic characteristics measurement test device that simulates intake flow. Another technical problem to be solved by the present invention is to provide an aircraft aerodynamic characteristics measurement test method that simulates intake flow, thereby reducing the interference of the downstream of the air inlet duct on the upstream flow and the interference of the support system on the flow on the surface of the ventilation model.

[0007] The aircraft aerodynamic characteristics measurement test device for simulating intake flow of the present invention comprises a supporting device, a variable sideslip angle device and a measuring device; The supporting device comprises a tail support bracket and a mounting platform, the tail of the ventilation strut is fixed to the upper part of the tail support bracket, the tail support bracket and the mounting platform are connected through a variable sideslip angle device, and the rear end of the mounting platform is fixedly connected to the scimitar mechanism of the wind tunnel; The variable sideslip angle device adopts a gear transmission mechanism, a chain transmission mechanism, a worm gear transmission mechanism or a track transmission mechanism to realize the rotation of the tail support bracket around the front section rotation axis of the mounting platform to change the sideslip angle of the ventilation model; The measuring device comprises a balance bellows, a ventilation support rod, a telescopic sleeve, a flowmeter adapter section, a flowmeter and an ejector which are sequentially connected from front to back, wherein the front and rear ends of the telescopic sleeve are respectively connected to the ventilation support rod and the flowmeter adapter section through a ball joint retaining ring, and the remaining components are connected through flanges; the front end of the balance bellows is connected to the air outlet of the ventilation model, and the outlet airflow of the ventilation model is discharged into the mainstream of the wind tunnel through the balance bellows, the ventilation support rod, the telescopic sleeve, the flowmeter adapter section, the flowmeter and the ejector; the flowmeter is fixedly supported by a flowmeter support fixed on the mounting platform, and the ejector is fixedly supported by an ejector support fixed on the mounting platform.

[0008] Furthermore, the track-type transmission mechanism comprises a side-sliding rotating workpiece and a mounting platform which are sequentially connected from front to back through a rotating shaft, and the side-sliding rotating workpiece and the mounting platform are matched with arc surfaces along the central axis direction of the rotating shaft according to the right-hand rule; the front section of the side-sliding rotating workpiece is connected to the rear section of the tail support bracket by screws which are equidistantly distributed around the circumference; A linear track workpiece is arranged on the left side of the installation platform, and a waist-shaped hole I with an inner diameter of R and parallel to the central axis of the wind tunnel is arranged on the linear track workpiece, and the waist-shaped hole I is the linear track I; A waist-shaped hole II with an inner diameter of R is arranged inside the side-sliding rotating workpiece, the angle between the center line of the waist-shaped hole II and the center line of the waist-shaped hole I is α, and the waist-shaped hole II is the linear track II; The linear track I and the linear track II intersect, and the intersection is an inscribed cylindrical cavity with an inner diameter of R and parallel to the central axis of the rotating shaft. A cylindrical actuating rod with an outer diameter of R is inserted into the inscribed cylindrical cavity, and the actuating rod and the linear track I and the linear track II are all linearly matched; A linear stepper motor fixed by a motor fixing support is also arranged on the left side of the installation platform, and a driving rod of the linear stepper motor is fixedly connected with an actuating rod.

[0009] Furthermore, the tail support bracket has an attack angle pre-bias.

[0010] Furthermore, the telescopic sleeve is provided with sealing rings on the outer surface of the inner sleeve and the inner surface of the outer sleeve respectively.

[0011] Furthermore, the angle α is an acute angle or an obtuse angle according to the right-hand rule.

[0012] Furthermore, the straight track II is replaced by a curved track.

[0013] Furthermore, the linear stepper motor is replaced by a power source for linear motion including an electric cylinder.

[0014] The aircraft aerodynamic characteristics measurement test method for simulating intake flow of the present invention comprises the following steps: S10. Wind tunnel test preparation; An aircraft aerodynamic characteristics measurement test device simulating the intake flow is installed in the wind tunnel, and the posture of the ventilation model is adjusted to the initial angle of attack and the initial sideslip angle; in conventional tests, the initial angle of attack and the initial sideslip angle are both zero degrees, and in high angle of attack tests, the angle of attack is pre-biased through the tail support bracket, and the initial angle of attack is not zero; S20. Conduct wind tunnel tests; Start the wind tunnel and establish a stable flow field; use the driving rod of the linear stepper motor to drive the actuator rod to move linearly along the linear track I, forcing the side-slip rotating workpiece to deflect around the rotation axis, converting the linear motion of the linear stepper motor into the rotational motion of the side-slip rotating workpiece, so that the ventilation model reaches the specified side-slip angle position, and the scimitar mechanism is used to achieve continuous changes in the angle of attack of the ventilation model; adjust and measure the airflow flow of the ventilation model through the flow meter, and increase the airflow flow simulation range of the ventilation model through the ejector; adjust the wind tunnel flow field speed according to the test plan, and obtain the aerodynamic characteristic data of the ventilation model under all test conditions; After the test, the wind tunnel was closed; S30. Experimental data processing; According to the requirements, the test data is processed to obtain the aerodynamic characteristics of the ventilation model.

[0015] The aircraft aerodynamic characteristics measurement test device and test method for simulating intake flow of the present invention have the following characteristics: 1. It truly reflects the shape of the duct from the inlet to the outlet of the aircraft inlet, accurately simulates the intake flow, and makes the test data more reliable; 2. The ventilation model is installed on the tail support bracket by the "tail support" method, and the flow meter and ejector are fixed on the installation platform by the "lifting" method through the flow meter support and the ejector support respectively; the "tail support + lifting" support method is adopted, which has little interference and realizes the "straight line" flow of the airflow at the outlet of the ventilation model inlet; 3. The sideslip angle of the ventilation model is driven by a track-type transmission with high transmission efficiency, which realizes the continuous adjustment of the sideslip angle; 4. The hollow telescopic sleeve with ball joints at both ends is used to compensate for the changes in the length and angle of the airflow pipeline caused by the sideslip angle deflection; 5. The telescopic sleeve adopts a "double-layer opposite-side" sealing design, which has high reliability and smooth telescopic movement.

[0016] The ventilation model of the aircraft aerodynamic characteristics measurement test device for simulating intake flow of the present invention is installed on the upper part of the tail support bracket through a balance bellows and a ventilation support rod, a variable sideslip angle device is installed between the rear section of the tail support bracket and the mounting platform, and measurement devices such as a flow meter and an ejector are fixed on the mounting platform, and the rear end of the mounting platform is fixedly connected to the scimitar mechanism of the wind tunnel; the variable sideslip angle device changes the sideslip angle of the ventilation model. The aircraft aerodynamic characteristics measurement test method for simulating intake flow of the present invention adopts the support mode of "tail support + lifting", realizes the perfect combination of the test system and the support system, solves the problem of difficulty in supporting the precise simulation test of intake flow in large-scale continuous wind tunnels, reduces the interference of the downstream flow of the intake duct on the upstream flow and the interference of the support system on the surface flow of the ventilation model, adopts track transmission, realizes the continuous adjustment of the sideslip angle; adopts ball joints at both ends and hollow telescopic sleeves, realizes the compensation of the change of airflow pipeline length and angle caused by the deflection of the sideslip angle.

[0017] The aircraft aerodynamic characteristics measurement test device and test method for simulating intake flow of the present invention provide a solution for accurate simulation of intake flow in large-scale continuous high-speed wind tunnels, and have engineering practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of an aircraft aerodynamic characteristics measurement test device for simulating intake flow of the present invention; Figure 2 It is a partial enlarged view of A of the aircraft aerodynamic characteristics measurement test device for simulating intake flow of the present invention.

[0019] In the figure, 1. ventilation model; 2. balance bellows; 3. ventilation support rod; 4. ball joint retaining ring; 5. tail support bracket; 6. telescopic sleeve; 7. side sliding rotating workpiece; 8. flow meter adapter section; 9. actuator rod; 10. driving rod; 11. linear track workpiece; 12. linear stepper motor; 13. motor fixed support; 14. flow meter; 15. flow meter support; 16. ejector; 17. ejector support; 18. installation platform; 19. scimitar mechanism. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the accompanying drawings.

[0021] Example: Figure 1 , Figure 2 As shown, the aircraft aerodynamic characteristics measurement test device for simulating intake flow of this embodiment includes a supporting device, a variable sideslip angle device and a measuring device; The supporting device includes a tail support bracket 5 and a mounting platform 18. The tail of the ventilation strut 3 is fixed to the upper part of the tail support bracket 5. The tail support bracket 5 and the mounting platform 18 are connected through a variable side slip angle device. The rear end of the mounting platform 18 is fixedly connected to the scimitar mechanism 19 of the wind tunnel. The side slip angle changing device adopts a gear transmission mechanism, a chain transmission mechanism, a worm gear transmission mechanism or a track transmission mechanism to realize the rotation of the tail support bracket 5 around the front section rotation axis of the mounting platform 18 to change the side slip angle of the ventilation model 1; The measuring device includes a balance bellows 2, a ventilation support rod 3, a telescopic sleeve 6, a flowmeter adapter section 8, a flowmeter 14 and an ejector 16 which are connected in sequence from front to back, wherein the front and rear ends of the telescopic sleeve 6 are respectively connected to the ventilation support rod 3 and the flowmeter adapter section 8 through a ball joint retaining ring 4, and the remaining components are connected through flanges; the front end of the balance bellows 2 is connected to the air outlet of the ventilation model 1, and the outlet airflow of the ventilation model 1 is discharged into the mainstream of the wind tunnel through the balance bellows 2, the ventilation support rod 3, the telescopic sleeve 6, the flowmeter adapter section 8, the flowmeter 14 and the ejector 16; the flowmeter 14 is fixedly supported by a flowmeter support 15 fixed on a mounting platform 18, and the ejector 16 is fixedly supported by an ejector support 17 fixed on the mounting platform 18.

[0022] Furthermore, the track-type transmission mechanism includes a side-sliding rotating workpiece 7 and a mounting platform 18 which are sequentially connected from front to back through a rotating shaft, and the side-sliding rotating workpiece 7 and the mounting platform 18 are matched with arc surfaces along the central axis direction of the rotating shaft according to the right-hand rule; the front section of the side-sliding rotating workpiece 7 is connected to the rear section of the tail support bracket 5 by screws equidistantly distributed around the circumference; A linear track workpiece 11 is arranged on the left side of the installation platform 18. A waist-shaped hole I with an inner diameter of R and parallel to the central axis of the wind tunnel is arranged on the linear track workpiece 11. The waist-shaped hole I is the linear track I. The side sliding rotating workpiece 7 is provided with a waist-shaped hole II with an inner diameter of R, the angle between the center line of the waist-shaped hole II and the center line of the waist-shaped hole I is α, and the waist-shaped hole II is a straight track II; The linear track I and the linear track II intersect, and the intersection is an inscribed cylindrical cavity with an inner diameter of R and parallel to the central axis of the rotating shaft. A cylindrical actuating rod 9 with an outer diameter of R is inserted into the inscribed cylindrical cavity. The actuating rod 9 is linearly matched with the linear track I and the linear track II. A linear stepping motor 12 fixed by a motor fixing support 13 is also arranged on the left side of the installation platform 18 , and a driving rod 10 of the linear stepping motor 12 is fixedly connected to the actuating rod 9 .

[0023] Furthermore, the tail support bracket 5 has a pre-biased angle of attack.

[0024] Furthermore, the telescopic sleeve 6 is provided with sealing rings on the outer surface of the inner sleeve and the inner surface of the outer sleeve respectively.

[0025] Furthermore, the angle α is an acute angle or an obtuse angle according to the right-hand rule.

[0026] Furthermore, the straight track II is replaced by a curved track.

[0027] Furthermore, the linear stepper motor 12 is replaced by a power source for linear motion including an electric cylinder.

[0028] The aircraft aerodynamic characteristics measurement test method of the present embodiment simulating intake flow includes the following steps: S10. Wind tunnel test preparation; An aircraft aerodynamic characteristic measurement test device simulating intake flow is installed in the wind tunnel, and the posture of the ventilation model 1 is adjusted to an initial angle of attack and an initial sideslip angle; in a conventional test, the initial angle of attack and the initial sideslip angle are both zero degrees, and in a large angle of attack test, the angle of attack is pre-biased by the tail support bracket 5, and the initial angle of attack is not zero; S20. Conduct wind tunnel tests; Start the wind tunnel and establish a stable flow field; drive the actuating rod 9 to move linearly along the linear track I through the driving rod 10 of the linear stepper motor 12, forcing the side-slip rotating workpiece 7 to deflect around the rotation axis, and convert the linear motion of the linear stepper motor 12 into the rotational motion of the side-slip rotating workpiece 7, so that the ventilation model 1 reaches the specified side-slip angle position, and the scimitar mechanism 19 realizes the continuous change of the angle of attack of the ventilation model 1; adjust and measure the airflow flow of the ventilation model 1 through the flowmeter 14, and increase the airflow flow simulation range of the ventilation model 1 through the ejector 16; adjust the wind tunnel flow field speed according to the test plan, and obtain the aerodynamic characteristic data of the ventilation model 1 under all test conditions; After the test, the wind tunnel was closed; S30. Experimental data processing; According to the requirements, the test data is processed to obtain the aerodynamic characteristics of the ventilation model 1.

[0029] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and the embodiments, and can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional improvements and modifications can be easily realized without departing from the principles of the present invention. Therefore, without departing from the general concept defined by the claims and equivalent scope, the present invention is not limited to the specific details and the illustrations shown and described here.

Claims

1. An aircraft aerodynamic characteristics measurement test device simulating intake flow, characterized in that: The aircraft aerodynamic characteristics measurement test device comprises a supporting device, a variable sideslip angle device and a measuring device; The support device comprises a tail support bracket (5) and a mounting platform (18), the tail of the ventilation strut (3) is fixed to the upper part of the tail support bracket (5), the tail support bracket (5) and the mounting platform (18) are connected via a variable sideslip angle device, and the rear end of the mounting platform (18) is fixedly connected to a scimitar mechanism (19) of the wind tunnel; The variable sideslip angle device uses a gear transmission mechanism, a chain transmission mechanism, a worm gear transmission mechanism or a track transmission mechanism to achieve the rotation of the tail support bracket (5) around the front section rotation axis of the mounting platform (18) to change the sideslip angle of the ventilation model (1); The measuring device comprises a balance bellows (2), a ventilation support rod (3), a telescopic sleeve (6), a flow meter adapter section (8), a flow meter (14) and an ejector (16) which are connected in sequence from front to back, wherein the front and rear ends of the telescopic sleeve (6) are respectively connected to the ventilation support rod (3) and the flow meter adapter section (8) via a ball joint retaining ring (4), and the remaining components are connected via flanges; the front end of the balance bellows (2) is connected to the air outlet of the ventilation model (1), and the outlet airflow of the ventilation model (1) is discharged into the mainstream of the wind tunnel through the balance bellows (2), the ventilation support rod (3), the telescopic sleeve (6), the flow meter adapter section (8), the flow meter (14) and the ejector (16); the flow meter (14) is fixedly supported by a flow meter support (15) fixed on a mounting platform (18), and the ejector (16) is fixedly supported by an ejector support (17) fixed on the mounting platform (18).

2. The aircraft aerodynamic characteristics measurement test device for simulating intake flow according to claim 1, characterized in that: The track-type transmission mechanism comprises a side-sliding rotating workpiece (7) and a mounting platform (18) which are sequentially connected from front to back via a rotating shaft, the side-sliding rotating workpiece (7) and the mounting platform (18) being matched with arc surfaces along the central axis direction of the rotating shaft according to the right-hand rule; the front section of the side-sliding rotating workpiece (7) is connected to the rear section of the tail support bracket (5) via screws which are equidistantly distributed around the circumference; A linear track workpiece (11) is arranged on the left side of the installation platform (18), and a waist-shaped hole I with an inner diameter R and parallel to the central axis of the wind tunnel is arranged on the linear track workpiece (11), and the waist-shaped hole I serves as the linear track I; The side-sliding rotating workpiece (7) is provided with a waist-shaped hole II with an inner diameter of R, the angle between the center line of the waist-shaped hole II and the center line of the waist-shaped hole I is α, and the waist-shaped hole II is a linear track II; The linear track I and the linear track II intersect, and the intersection is an inscribed cylindrical cavity with an inner diameter R and parallel to the central axis of the rotating shaft. A cylindrical actuating rod (9) with an outer diameter R is inserted into the inscribed cylindrical cavity, and the actuating rod (9) and the linear track I and the linear track II are all linearly matched; A linear stepping motor (12) fixed by a motor fixing support (13) is also arranged on the left side of the mounting platform (18), and a driving rod (10) of the linear stepping motor (12) is fixedly connected to an actuating rod (9).

3. The aircraft aerodynamic characteristics measurement test device for simulating intake flow according to claim 2, characterized in that: The tail support bracket (5) has an angle of attack pre-bias.

4. The aircraft aerodynamic characteristics measurement test device for simulating intake flow according to claim 2, characterized in that: The telescopic sleeve (6) is provided with sealing rings on the outer surface of the inner sleeve and the inner surface of the outer sleeve respectively.

5. The aircraft aerodynamic characteristics measurement test device for simulating intake flow according to claim 2, characterized in that: The angle α is an acute angle or an obtuse angle according to the right-hand rule.

6. The aircraft aerodynamic characteristics measurement test device for simulating intake flow according to claim 2, characterized in that: The linear track II is replaced by a curved track.

7. The aircraft aerodynamic characteristics measurement test device for simulating intake flow according to claim 2, characterized in that: The linear stepper motor (12) is replaced by a power source for linear motion including an electric cylinder.

8. A method for measuring the aerodynamic characteristics of an aircraft simulating intake flow, which is used in the aerodynamic characteristics measuring test device for simulating intake flow of an aircraft as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: S10. Wind tunnel test preparation; An aircraft aerodynamic characteristics measurement test device simulating intake flow is installed in a wind tunnel, and the posture of the ventilation model (1) is adjusted to an initial angle of attack and an initial sideslip angle; in a conventional test, the initial angle of attack and the initial sideslip angle are both zero degrees, and in a high angle of attack test, an angle of attack pre-bias is achieved through a tail support bracket (5), and the initial angle of attack is not zero; S20. Conduct wind tunnel tests; The wind tunnel is started to establish a stable flow field; the driving rod (10) of the linear stepper motor (12) drives the driving rod (9) to move linearly along the linear track I, forcing the side-slip rotating workpiece (7) to deflect around the rotation axis, converting the linear motion of the linear stepper motor (12) into the rotational motion of the side-slip rotating workpiece (7), so that the ventilation model (1) reaches a specified side-slip angle position, and the scimitar mechanism (19) is used to achieve a continuous change in the angle of attack of the ventilation model (1); the airflow rate of the ventilation model (1) is adjusted and measured by the flow meter (14), and the airflow rate simulation range of the ventilation model (1) is increased by the ejector (16); according to the test plan, the wind tunnel flow field speed is adjusted to obtain the aerodynamic characteristic data of the ventilation model (1) under all test conditions; After the test, the wind tunnel was closed; S30. Experimental data processing; According to the requirements, the test data is processed to obtain the aerodynamic characteristics of the ventilation model (1).

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