Wind tunnel test device and method for simulating aircraft to eject suspension object backwards

Abstract

The invention discloses a wind tunnel test device for simulating an aircraft to eject a hanging object backwards, which comprises an ejection cylinder (1), an ejection piston (2) is slidably connected in the ejection cylinder (1) along the axial direction, the head end of the ejection cylinder (1) is provided with an ejection gas inlet (3), the ejection piston (2) is connected with the hanging object (4), and the ejection piston (2) and the hanging object (4) are locked into a whole through a locking mechanism (5). The device is simple in structure, convenient and flexible in speed angular speed adjustment, good in repeatability, high in reliability and easy and convenient to install.

Description

Technical Field

[0001] The invention belongs to the technical field of aircraft wind tunnel tests, and in particular relates to a wind tunnel test device and method for simulating an aircraft to eject a suspended object backward. Background Art

[0002] The wind tunnel free drop test is a special wind tunnel test. Different from the conventional wind tunnel test, which requires the model to be fixed in the wind tunnel flow field and the aerodynamic force to be measured by a balance, the model in the free drop test can move freely in the wind tunnel flow field. Under the action of aerodynamic force and gravity, the model moves along a trajectory that satisfies the laws of physics. The trajectory change data can be obtained by optical measurement methods, and the aerodynamic changes of the model can be obtained by analyzing the trajectory data. Free drop is the wind tunnel test that is closest to real flight drop, and can fully simulate unsteady aerodynamic characteristics.

[0003] In order to achieve the aerodynamic high lift-to-drag ratio requirements, the suspension is usually installed in the belly compartment of the aircraft. When dropping, the belly door needs to be opened from the side, and the suspension is ejected from the direction perpendicular to the axis of the aircraft body using the ejection rack. After the door is opened, this solution will form a typical cavity flow. This type of flow has complex airflow changes and no unique solution. It has a relatively large interference with flight stability and the trajectory of the drop of the suspension. If the suspension is installed in the launch tube, when launching, it only needs to rotate the launch tube a small angle so that the rear end launch tube mouth is completely exposed to the belly plane, and the suspension can be ejected along the axis of the launch tube in the opposite direction of the flight direction. After the suspension leaves the tube, there needs to be a head-down angular velocity to ensure the safety of the drop. This solution can avoid the adverse effects of the cavity effect on the drop.

[0004] For this type of rearward ejection suspension delivery scheme, since the aerodynamic forces change rapidly and complexly during the delivery process, and unsteady aerodynamic forces play a dominant role, free delivery wind tunnel tests must be carried out to ensure the safety of the ejection delivery. It is also necessary to study the feasibility and safety of separation as well as the impact of various factors on the safety of delivery and separation. Summary of the invention

[0005] The purpose of the present invention is to provide a wind tunnel test device and method for simulating an aircraft ejecting a suspended object backward. The present invention has a simple structure, convenient and flexible speed and angular velocity adjustment, good repeatability, high reliability and easy installation.

[0006] The technical solution of the present invention is a wind tunnel test device for simulating an aircraft ejecting a suspended object backward, comprising an ejection cylinder, an ejection piston axially slidably connected inside the ejection cylinder, an ejection gas inlet being arranged at the head end of the ejection cylinder, the ejection piston being connected to the suspended object and being locked as a whole with the ejection piston via a locking mechanism.

[0007] In the aforementioned wind tunnel test device simulating an aircraft ejecting a suspended object backward, the ejection cylinder and the ejection piston are slidably connected via a guide mechanism; the guide mechanism includes a guide rail arranged on the inner wall of the ejection cylinder and a guide rail pin arranged on the ejection piston, and the guide rail pin is slidably connected to the guide rail.

[0008] In the aforementioned wind tunnel test device simulating an aircraft ejecting a suspended object backward, a blocking screw for axially limiting the guide rail pin is provided on the guide rail.

[0009] In the aforementioned wind tunnel test device simulating an aircraft ejecting a suspended object backward, the locking mechanism includes a locking cylinder fixed to the side wall of the ejection cylinder, a locking piston is slidably connected inside the locking cylinder, the locking piston is connected to a locking pin, the locking pin passes through the side wall of the ejection cylinder and the side wall of the ejection piston in sequence and then gets stuck in the suspended object; a locking spring is provided between the side of the locking piston away from the locking pin and the locking cylinder, and an unlocking air inlet is provided on the side wall of the locking cylinder between the locking piston and the ejection cylinder.

[0010] In the aforementioned wind tunnel test device simulating an aircraft ejecting a suspended object backward, an angular velocity providing mechanism is provided on the side in the extension direction of the tail end of the ejection cylinder, the angular velocity providing mechanism includes an angular velocity cylinder, an angular velocity piston is slidably connected inside the angular velocity cylinder, the angular velocity piston is connected to a striker rod, the striker rod can extend out of the angular velocity cylinder, an angular velocity spring is mounted on the striker rod, and an angular velocity air supply inlet is provided on the angular velocity cylinder.

[0011] The method for using the aforementioned wind tunnel test device simulating an aircraft ejecting a suspended object backwards comprises the following steps:

[0012] S1. Install the wind tunnel test device on the belly of the aircraft and place it in the wind tunnel;

[0013] S2. During the wind tunnel test, when the flow field meets the requirements, the locking mechanism is unlocked, and high-pressure gas is introduced into the ejection gas inlet to push the ejection piston backward to eject the suspended object backward into the wind tunnel flow field. The influence of various ejection parameters on separation safety is examined, and separation aerodynamic data is obtained.

[0014] In the aforementioned method of using the wind tunnel test device simulating an aircraft ejecting a suspended object backward, in step 2, the unlocking process is as follows: the unlocking air inlet is ventilated, and the locking piston is pushed to drive the locking pin to retract into the locking cylinder to complete the unlocking.

[0015] In the aforementioned method of using the wind tunnel test device simulating an aircraft ejecting a suspension backward, in step 2, when it is necessary to provide an angle for the suspension, when the head end of the suspension is ejected from the ejection cylinder, the high-pressure gas at the angle angular velocity air supply inlet pushes the striker rod to hit the head end of the suspension through the angular velocity piston, so that the suspension obtains an angular velocity.

[0016] Beneficial effects of the present invention:

[0017] 1. The research and development of wind tunnel high-speed free-drop test equipment for the mechanism of rearward ejection was realized from scratch, which enabled the high-speed free-drop test to realize the key capability of simulating the aircraft's rearward ejection of suspended objects for the first time;

[0018] 2. The present invention has high versatility and can realize the technical requirements of rearward ejection of various suspended objects of different sizes and shapes;

[0019] 3. The invention is applicable to a wide range of scaled ejection suspension models, with a mass range of 10 to 700 g, an ejection speed range of 1 to 10 m / s, an angular velocity adjustment range of 0 to 600 degrees / s, and an ejection angle that is convenient and adjustable (applicable to backward ejection within a range of 90 degrees);

[0020] 4. As a component of a wind tunnel model, the present invention can make full use of the limited space of an aircraft, has a simple and efficient structure, and can be applied to the current wind tunnel test model with an embedded cabin;

[0021] 5. The present invention has high adjustment and wide applicability and high stability. Under the conditions of the same ejection pressure and action time, it can realize multiple repeated ejections of the suspended object model under the same speed and angular velocity separation conditions.

[0022] 6. The present invention can realize ejection of suspended objects at different speeds by adjusting the ejection cylinder pressure, and can add different angular velocities to the suspended objects by adjusting the action time and cylinder pressure of the angular velocity cylinder. It has a simple structure, convenient and flexible speed and angular velocity adjustment, good repeatability, high reliability and easy installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the present invention;

[0024] Figure 2 It is a front cross-sectional view of the assembly of the present invention;

[0025] Figure 3 It is a top sectional view of the assembly of the present invention;

[0026] Figure 4 This is a schematic diagram of the mechanism unlocking and ejection timing;

[0027] Figure 5 Schematic diagram of the model's angular motion. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Embodiment 1. A wind tunnel test device and method for simulating an aircraft ejecting a suspended object backwards, see Figure 1-Figure 5 , including an ejection cylinder 1, an ejection piston 2 is axially slidably connected in the ejection cylinder 1, an ejection gas inlet 3 is provided at the head end of the ejection cylinder 1, the ejection piston 2 is connected to the hanging object 4, and is locked as a whole with the ejection piston 2 through a locking mechanism 5. The present invention has a simple structure and high reliability, and can simulate the ejection speed and angular velocity corresponding to different flight altitudes and speeds. By adjusting the ejection pressure of the ejection cylinder 1, different speeds can be obtained, thereby realizing the speed simulation of the model.

[0030] The ejection cylinder 1 and the ejection piston 2 are slidably connected via a guide mechanism 6; the guide mechanism 6 includes a guide rail 61 arranged on the inner wall of the ejection cylinder 1, and a guide rail pin 62 arranged on the ejection piston 2, and the guide rail pin 62 is slidably connected to the guide rail 61.

[0031] The aforementioned guide rail 61 is provided with a blocking screw 63 for axially limiting the guide rail pin 62 .

[0032] The aforementioned locking mechanism 5 includes a locking cylinder 51 fixed to the side wall of the ejection cylinder 1, a locking piston 52 is slidably connected inside the locking cylinder 51, the locking piston 52 is connected to a locking pin 53, the locking pin 53 passes through the side wall of the ejection cylinder 1 and the side wall of the ejection piston 2 in sequence and then gets stuck in the hanging object 4; a locking spring 54 is provided between the side of the locking piston 52 away from the locking pin 53 and the locking cylinder 51, and an unlocking air inlet 55 is provided on the side wall of the locking cylinder 51 between the locking piston 52 and the ejection cylinder 1.

[0033] The side of the ejection cylinder 1 in the extension direction of the tail end is provided with an angular velocity providing mechanism 7, which includes an angular velocity cylinder 71, an angular velocity piston 72 is slidably connected in the angular velocity cylinder 71, and the angular velocity piston 72 is connected to the striker 73, and the striker 73 can extend out of the angular velocity cylinder 71, and the striker 73 is sleeved with an angular velocity spring 74, and the angular velocity cylinder 71 is provided with an angular velocity air supply inlet 75. After the suspended object 4 is ejected from the ejection cylinder 1, the timing is set to start the angular velocity cylinder 71, and the angular velocity piston 72 moves downward, pushing the striker 73 to act on the front of the suspended object, so that the suspended object 4 obtains a downward angular velocity. By adjusting the start time and action time of the angular velocity cylinder 71, the angular velocity of the suspended object can be adjusted to achieve different angular velocity controls.

[0034] Multiple cylinders are used as ejection power, unlocking power, and angular acceleration power for the suspended object. Through timing control, a complete unlocking, ejection, and angular velocity-added backward launching process of the suspended object is formed.

[0035] Due to space limitations, the aircraft's belly compartment and the ejection cylinder are designed to be integrated into one. The ejection cylinder is a container for loading suspended objects before ejection.

[0036] The contact part between the ejection piston and the suspension is designed to be a surface consistent with the appearance of the suspension. The suspension is embedded in the piston. Before ejection, the suspension is fixed on the piston. The piston can only move backward along the axis of the cylinder. Due to the limitation of the matching surface, the suspension can only move backward away from the piston. A pin is designed to penetrate the cylinder wall and the piston wall and insert into the small hole of the suspension body, which can lock the piston and the suspension at the same time. Unlocking can be achieved by simply designing an unlocking cylinder and pulling out the pin.

[0037] By adjusting the ejection cylinder pressure, the suspended object can be ejected at different speeds. By adjusting the action time and cylinder pressure of the angular velocity cylinder, different angular velocities can be added to the suspended object.

[0038] The method for using the aforementioned wind tunnel test device simulating an aircraft ejecting a suspended object backwards comprises the following steps:

[0039] S1. Install the wind tunnel test device on the belly of the aircraft and place it in the wind tunnel;

[0040] S2. During the wind tunnel test, when the flow field meets the requirements, the locking mechanism 5 is unlocked, and high-pressure gas is introduced into the ejection gas inlet 3 to push the ejection piston 2 to eject backwards, ejecting the suspended object 4 backwards into the wind tunnel flow field, examining the influence of various ejection parameters on separation safety, and obtaining separation aerodynamic data.

[0041] In step 2, the unlocking process is as follows: the unlocking air inlet 55 is ventilated, pushing the locking piston 52 to drive the locking pin 53 to retract into the locking cylinder 51 to complete the unlocking.

[0042] In step 2, when it is necessary to provide an angle for the suspension 4, when the head end of the suspension 4 is ejected from the ejection cylinder 1, the high-pressure gas at the angle angular velocity air supply inlet 75 pushes the impact rod 73 through the angular velocity piston 72 to hit the head end of the suspension 4, so that the suspension 4 obtains a downward angular velocity.

[0043] The above is only a specific embodiment of the present invention, and the present invention is described in detail. The unexplained part is a conventional technology. However, the protection scope of the present invention is not limited to this. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A wind tunnel test device simulating an aircraft ejecting a suspended object backward, characterized in that: The invention comprises an ejection cylinder (1), wherein an ejection piston (2) is axially slidably connected inside the ejection cylinder (1), an ejection gas inlet (3) is provided at the head end of the ejection cylinder (1), the ejection piston (2) is connected to a hanging object (4), and is locked as a whole with the ejection piston (2) via a locking mechanism (5).

2. The wind tunnel test device for simulating the rearward ejection of a suspended object by an aircraft according to claim 1, characterized in that: The ejection cylinder (1) and the ejection piston (2) are slidably connected via a guide mechanism (6); the guide mechanism (6) comprises a guide rail (61) arranged on the inner wall of the ejection cylinder (1) and a guide rail pin (62) arranged on the ejection piston (2); the guide rail pin (62) is slidably connected to the guide rail (61).

3. The wind tunnel test device for simulating the rearward ejection of a suspended object by an aircraft according to claim 2, characterized in that: The guide rail (61) is provided with a blocking screw (63) for axially limiting the guide rail pin (62).

4. The wind tunnel test device for simulating the rearward ejection of a suspended object by an aircraft according to claim 1, characterized in that: The locking mechanism (5) comprises a locking cylinder (51) fixed to the side wall of the ejection cylinder (1), a locking piston (52) slidably connected in the locking cylinder (51), the locking piston (52) being connected to a locking pin (53), the locking pin (53) passing through the side wall of the ejection cylinder (1) and the side wall of the ejection piston (2) in sequence and then being clamped into the hanging object (4); a locking spring (54) is arranged between the side of the locking piston (52) away from the locking pin (53) and the locking cylinder (51), and an unlocking air inlet (55) is arranged on the side wall of the locking cylinder (51) between the locking piston (52) and the ejection cylinder (1).

5. The wind tunnel test device for simulating the rearward ejection of a suspended object by an aircraft according to claim 1, characterized in that: An angular velocity providing mechanism (7) is provided on the side of the ejection cylinder (1) in the extension direction of the tail end. The angular velocity providing mechanism (7) comprises an angular velocity cylinder (71). An angular velocity piston (72) is slidably connected in the angular velocity cylinder (71). The angular velocity piston (72) is connected to a striker rod (73). The striker rod (73) can extend out of the angular velocity cylinder (71). An angular velocity spring (74) is sleeved on the striker rod (73). An angular velocity air supply inlet (75) is provided on the angular velocity cylinder (71).

6. A method for using the wind tunnel test device for simulating an aircraft ejecting a suspended object backwards as claimed in any one of claims 1 to 5, characterized in that: The steps include: S1. Install the wind tunnel test device on the belly of the aircraft and place it in the wind tunnel; S2. During the wind tunnel test, when the flow field meets the requirements, the locking mechanism (5) is unlocked, and high-pressure gas is introduced into the ejection gas inlet (3) to push the ejection piston (2) to eject backwards, ejecting the suspended object (4) backwards into the wind tunnel flow field, examining the influence of various ejection parameters on separation safety, and obtaining separation aerodynamic data.

7. The method for using the wind tunnel test device for simulating the rear ejection of a suspended object by an aircraft as claimed in claim 6, characterized in that: In step 2, the unlocking process is as follows: the unlocking air inlet (55) is ventilated, pushing the locking piston (52) to drive the locking pin (53) to retract into the locking cylinder (51) to complete the unlocking.

8. The method for using the wind tunnel test device for simulating the rear ejection of a suspended object by an aircraft as claimed in claim 6, characterized in that: In step 2, when it is necessary to provide an angle for the suspended object (4), when the head end of the suspended object (4) is ejected from the ejection cylinder (1), the high-pressure gas of the angle angular velocity air supply inlet (75) pushes the striker (73) to hit the head end of the suspended object (4) through the angular velocity piston (72), so that the suspended object (4) obtains an angular velocity.

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