A dynamic similarity simulation device for wind tunnel virtual flight tests

Abstract

The present invention relates to the technical field of wind tunnel dynamic simulation, and discloses a dynamic similarity simulation device for virtual flight tests in a wind tunnel, including: a first connecting member rotatably arranged on a gas source device along a first direction; a second connecting member rotatably arranged on the first connecting member along a second direction; a third connecting member connected to the second connecting member; a fourth connecting member rotatably arranged on the third connecting member along a third direction; the first connecting member has a plurality of gas source inlets, and the fourth connecting member has a plurality of gas source outlets. Airflow enters from the gas source inlets, flows along the first connecting member, the second connecting member, the third connecting member and the fourth connecting member, and is discharged from the gas source outlets; wherein, along the flowing direction of the airflow, the cross-sectional area of the inner cavity of the second connecting member is larger than the cross-sectional area of the inner cavity of the first connecting member. By the above method, the present invention solves the technical problem that it is difficult to simultaneously simulate the thrust-to-weight ratio and the pressure drop ratio on a scaled model in the wind tunnel simulation of aircraft tests in the related art.

Description

Technical Field

[0001] The present invention relates to the technical field of wind tunnel dynamic simulation, and particularly to a dynamic similarity simulation device for wind tunnel virtual flight tests. Background Art

[0002] In recent years, advanced aircraft have widely adopted unconventional aerodynamic configurations, presenting new non-linear characteristics, and their aerodynamic, flight control, and propulsion systems are highly coupled. With the application of thrust vector control technology and the development of modern control theories such as auto-disturbance rejection, dynamic inversion, and reconfiguration control, there is an urgent need for a dynamic similarity device that can simultaneously simulate the thrust-to-weight ratio and the pressure ratio on a scaled model to conduct wind tunnel virtual flight test research and verification on the aerodynamic layout and flight control of the aircraft in the preliminary design stage.

[0003] Therefore, providing a dynamic similarity simulation device for wind tunnel virtual flight tests that can simultaneously simulate the thrust-to-weight ratio and the pressure ratio on a scaled model is a technical problem that needs to be urgently solved by those skilled in the art. Summary of the Invention

[0004] The present invention discloses a dynamic similarity simulation device for wind tunnel virtual flight tests to solve the technical problem that it is difficult to simultaneously simulate the thrust-to-weight ratio and the pressure ratio on a scaled model in the wind tunnel simulation test of an aircraft.

[0005] To solve the above problems, the present invention adopts the following technical solutions:

[0006] A dynamic similarity simulation device for wind tunnel virtual flight tests, comprising:

[0007] A first connecting member rotatably arranged on a gas source device along a first direction;

[0008] A second connecting member rotatably arranged on the first connecting member along a second direction;

[0009] A third connecting member connected to the second connecting member;

[0010] A fourth connecting member rotatably arranged on the third connecting member along a third direction;

[0011] The first connecting member has a plurality of gas source inlets, and the fourth connecting member has a plurality of gas source outlets. Airflow enters from the gas source inlets, flows along the first connecting member, the second connecting member, the third connecting member, and the fourth connecting member, and discharges from the gas source outlets;

[0012] Wherein, along the flowing direction of the airflow in the first connecting member, the cross-sectional area of the inner cavity of the second connecting member is larger than the cross-sectional area of the inner cavity of the first connecting member.

[0013] In some embodiments, the first connecting member has a first flow portion and a second flow portion, and there are two second connecting members;

[0014] One end of the first flow portion is provided with a gas source inlet, and the other end is connected to the second flow portion; the two air outlets of the second flow portion are respectively connected to the air inlets of the two second connectors.

[0015] Wherein, along the flow direction of the gas flow in the second flow portion, the cross-sectional area of the inner cavity of the second connector is larger than the cross-sectional area of the inner cavity of the second flow portion.

[0016] In some solutions, the third connector has a third flow portion and a fourth flow portion;

[0017] The third flow portion is connected to the fourth flow portion, and the two air inlets of the third flow portion are respectively connected to the air outlets of the two second connectors.

[0018] In some solutions, the second flow portion and the third flow portion are respectively located between the two second connectors;

[0019] The distances between the first flow portion and the two second connectors are equal, and the distances between the fourth flow portion and the two second connectors are equal.

[0020] In some solutions, along the flow direction of the gas flow in the first flow portion, the cross-sectional area of the inner cavity of the second flow portion is larger than the cross-sectional area of the inner cavity of the first flow portion.

[0021] In some solutions, along the flow direction of the gas flow in the fourth flow portion, the cross-sectional area of the inner cavity of the fourth connector is larger than the cross-sectional area of the inner cavity of the fourth flow portion.

[0022] In some solutions, along the flow direction of the gas flow in the third flow portion, the cross-sectional area of the inner cavity of the third flow portion is larger than the cross-sectional area of the air outlet of the second connector.

[0023] In some solutions, along the flow direction of the gas flow, the ratio of the cross-sectional area of the inner cavity of the third flow portion to the cross-sectional area of the air outlet of the second connector is smaller than the ratio of the cross-sectional area of the inner cavity of the second connector to the cross-sectional area of the inner cavity of the second flow portion.

[0024] In some solutions, the distances between several gas source outlets and the third connector are respectively equal.

[0025] In some solutions, several gas source outlets are respectively connected to Laval nozzles through diversion pipes.

[0026] The technical solution adopted by the present invention can achieve the following beneficial effects:

[0027] The dynamic similarity simulation device for wind tunnel virtual flight tests of the present application, in the tests for aircraft, the air flow enters from the air source inlet and flows along the first connecting member, the second connecting member, the third connecting member and the fourth connecting member, and is discharged from the air source outlet. When the air flow enters from the first connecting member into the second connecting member, the cross-sectional area suddenly becomes larger, causing the air flow to form an in-tube shock wave here and quickly decelerate and expand, converting the kinetic energy of the air flow into pressure energy. At the same time, along with frictional losses, eddy current losses, etc., the total pressure at the outlet of the system decreases, thereby significantly reducing the total pressure recovery coefficient of the air flow, imposing a forced total pressure loss on the air flow, reducing the total pressure of the air flow to an appropriate range, and meeting the simulation test requirements for the similarity of the thrust-to-weight ratio and the pressure drop ratio of the aircraft. Moreover, the first connecting member can rotate in the first direction, the second connecting member can rotate in the second direction, and the fourth connecting member can rotate in the third direction, making the simulation device have three angular degrees of freedom of movement, further meeting the simulation test requirements of the aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 is the axonometric view of the dynamic similarity simulation device for wind tunnel virtual flight tests of the present invention;

[0030] Figure 2 is the top view of the dynamic similarity simulation device for wind tunnel virtual flight tests of the present invention;

[0031] Figure 3 is Figure 2 the sectional view taken along the A-A plane in

[0032] Figure 4 is the front view of the dynamic similarity simulation device for wind tunnel virtual flight tests of the present invention Figure 1 ;

[0033] Figure 5 is Figure 4 the sectional view taken along the B-B plane in

[0034] Figure 6 is the front view of the dynamic similarity simulation device for wind tunnel virtual flight tests of the present invention Figure 2 ;

[0035] Figure 7 is Figure 6 the sectional view taken along the C-C plane in

[0036] Figure 8 isFigure 7 Enlarged view at position E;

[0037] Figure 9 is Figure 7 Enlarged view at position F;

[0038] Figure 10 is Figure 6 Cross-sectional view along plane D-D;

[0039] Figure 11 is Figure 10 Enlarged view at position G.

[0040] In the figure:

[0041] 100 - First connecting member, 110 - First flow portion, 111 - Gas source inlet, 120 - Second flow portion;

[0042] 200 - Second connecting member;

[0043] 300 - Third connecting member, 310 - Third flow portion, 320 - Fourth flow portion;

[0044] 400 - Fourth connecting member, 410 - Gas source outlet;

[0045] 500 - Laval nozzle, 510 - Guide pipe;

[0046] 600 - First sealing joint, 610 - First connecting portion, 620 - First sealing labyrinth inner ring, 630 - First sealing labyrinth outer ring, 640 - First bearing;

[0047] 700 - Second sealing joint, 710 - Second sealing labyrinth inner ring, 720 - Second sealing labyrinth outer ring, 730 - Second bearing;

[0048] 800 - Third sealing joint, 810 - Third sealing labyrinth inner ring, 820 - Third sealing labyrinth outer ring, 830 - Third bearing. Detailed implementation manners

[0049] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other implementation manners obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope protected by the present invention.

[0050] The terms "first", "second", etc. in the description and claims of this application are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of this application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are usually of the same category, and do not limit the number of objects. For example, the first object can be one or more. In addition, "and / or" in the description and claims means at least one of the connected objects, and the character " / ", generally represents an "or" relationship between the associated objects before and after.

[0051] During the process of using the wind tunnel to test the aircraft, the inventors found that due to the widespread adoption of unconventional aerodynamic configurations by aircraft in recent years, presenting new non-linear characteristics, the aerodynamic, flight control, and propulsion systems are highly coupled. At the same time, with the application of thrust vector control technology and the development of modern control theories such as active disturbance rejection control, dynamic inversion, and reconfiguration control, in the early design stage, if the wind tunnel equipment is used to test the aircraft, the cost is high and the efficiency is low.

[0052] The following combines the attached Figures 1 to 11 , and through specific embodiments and their application scenarios, a dynamic similarity simulation device for wind tunnel virtual flight tests provided by this application is described in detail.

[0053] As Figure 1 , Figure 2 and Figure 4 shown, a dynamic similarity simulation device for wind tunnel virtual flight tests includes a first connector 100, a second connector 200, a third connector 300, a fourth connector 400, a guide pipe 510, and a Laval nozzle 500.

[0054] As Figure 1 shown, the first connector 100 is rotatably arranged on the gas source device along a first direction, the second connector 200 is rotatably arranged on the first connector 100 along a second direction, the third connector 300 is connected to the second connector 200, and the fourth connector 400 is rotatably arranged on the third connector 300 along a third direction.

[0055] When the aircraft moves in space, it not only has translational degrees of freedom along three mutually perpendicular axes (longitudinal axis, lateral axis, vertical axis), but also has angular motion degrees of freedom about these three axes. These angular motion degrees of freedom include roll about the longitudinal axis, pitch about the lateral axis, and yaw about the vertical axis.

[0056] The rotation of the first connecting member 100 in the first direction is used for yaw simulation tests, which can simulate the yaw conditions of the aircraft under crosswind, downwind or headwind conditions, etc., so as to evaluate the performance of its yaw control system. The rotation of the second connecting member 200 in the second direction is used for pitch simulation tests, which can simulate the pitch moment changes encountered by the aircraft during different climbing or descending stages, and then evaluate the stability and response speed of its pitch control system. The rotation of the fourth connecting member 400 in the third direction is used for roll simulation tests. It can simulate the roll moment changes encountered by the aircraft during maneuvers such as turning or rolling, so as to evaluate the performance of its roll control system.

[0057] Among them, the first direction is as shown by O1 in Figure 1 , the second direction is as shown by O2 in Figure 1 , and the third direction is as shown by O3 in Figure 1 .

[0058] As shown in Figure 3 and Figure 5 , the first connecting member 100, the second connecting member 200, the third connecting member 300 and the fourth connecting member 400 respectively have inner cavities, and the first connecting member 100 has a plurality of gas source inlets 111, and the fourth connecting member 400 has a plurality of gas source outlets 410. The air flow enters from the gas source inlet 111, flows along the first connecting member 100, the second connecting member 200, the third connecting member 300 and the fourth connecting member 400, and discharges from the gas source outlet 410, simulating the air flow conditions encountered by the aircraft during actual flight.

[0059] As shown in Figure 3 and Figure 5 , along the flow direction of the air flow in the first connecting member 100, the cross-sectional area of the inner cavity of the second connecting member 200 is larger than that of the inner cavity of the first connecting member 100.

[0060] When the air flow enters from the first connecting member 100 into the second connecting member 200, the cross-sectional area of the second connecting member 200 suddenly becomes larger, causing the air flow to form an in-pipe shock wave here and quickly decelerate and expand. The kinetic energy of the air flow is converted into pressure energy, and at the same time, there are friction losses, eddy current losses, etc., resulting in a decrease in the total pressure at the outlet of the system, and then a significant reduction in the total pressure recovery coefficient of the air flow, causing a forced total pressure loss to the air flow, so that the total pressure of the air flow is reduced to an appropriate range to meet the simulation test requirements of the aircraft.

[0061] As shown in Figure 3 and Figure 5 , the first connecting member 100 has a first flow portion 110 and a second flow portion 120. Specifically, the gas source inlet 111 is arranged at one end of the first flow portion 110, and the other end of the first flow portion 110 is vertically connected to the middle of the second flow portion 120, forming a T-shaped structure.

[0062] Both the first flow portion 110 and the second flow portion 120 have inner cavities that penetrate along their respective axial directions. The air source inlet 111 is provided at the end of the first flow portion 110. Airflow enters the first flow portion 110 from the air source inlet 111 and then enters the second flow portion 120. When the airflow enters the second flow portion 120 from the first flow portion 110, the cross-sectional area of the second flow portion 120 suddenly increases, and the airflow will also decelerate and expand here to a certain extent, reducing the total pressure recovery coefficient of the airflow within a certain range and causing a forced total pressure loss to the airflow.

[0063] Preferably in this embodiment, the number of the air source inlets 111 is 1. It goes without saying that the number of the air source inlets 111 can also be more, and this embodiment does not limit this.

[0064] As Figures 1 - 3 and Figure 5 shown, there are two second connectors 200, and the second flow portion 120 is respectively connected to the air inlets of the second connectors 200. Specifically, along the flow direction of the airflow in the second flow portion 120, the cross-sectional area of the inner cavity of the second connector 200 is larger than the cross-sectional area of the inner cavity of the second flow portion 120.

[0065] When the airflow enters the second connector 200 from the second flow portion 120, the cross-sectional area of the second connector 200 suddenly increases, causing the airflow to form an in-tube shock wave here and quickly decelerate and expand. The kinetic energy of the airflow is converted into pressure energy, and at the same time, there are frictional losses, eddy current losses, etc., resulting in a decrease in the total pressure at the outlet of the system, thereby greatly reducing the total pressure recovery coefficient of the airflow, causing a forced total pressure loss to the airflow, and reducing the total pressure of the airflow to an appropriate range to meet the simulation test requirements of the aircraft.

[0066] In this embodiment, the air inlets of the two second connectors 200 are provided on the opposite side walls, and the second flow portion 120 is located in the middle of the two second connectors 200. During the rotation of the two second connectors 200 in the second direction, the force on the first connector 100 is uniform and unified, which is beneficial to increasing the structural stability of the simulation device.

[0067] It should be noted that the cross-sectional ratio of the first flow portion 110 to the second flow portion 120 is smaller than the cross-sectional ratio of the second flow portion 120 to the second connector 200. With such a setting, the second connector 200 mainly undertakes the task of airflow deceleration and expansion, and the second flow portion 120 mainly undertakes the task of pitch simulation test.

[0068] In this embodiment, the middle part of the first flow portion 110 is connected to the second flow portion 120, and the distances between the first flow portion 110 and the two second connectors 200 are equal. When the air flow enters from the air source inlet 111, it passes through the first flow portion 110 and the second flow portion 120 and then enters the second connector 200. Since the distances between the first flow portion 110 and the two second connectors 200 are equal, the air flow introduced from the first flow portion 110 enters the two second connectors 200 with equal flow rates, ensuring the uniformity of the air flow in the system.

[0069] As Figure 5 shown, the third connector 300 has a third flow portion 310 and a fourth flow portion 320. Specifically, the air inlets at both ends of the third flow portion 310 are respectively connected to the air outlets of the two second connectors 200. One end of the fourth flow portion 320 is vertically connected to the middle part of the third flow portion 310, forming a T-shaped structure, and the other end is rotatably connected to the fourth connector 400.

[0070] Both the third flow portion 310 and the fourth flow portion 320 have inner cavities that penetrate along their respective axial directions. The air flow discharged from the second connector 200 enters the third flow portion 310 and then passes through the fourth flow portion 320 and enters the fourth connector 400. The fourth flow portion 320 is rotatably connected to the fourth connector 400, enabling the fourth connector 400 to rotate in the third direction to simulate a rolling simulation test.

[0071] In this embodiment, the middle part of the fourth flow portion 320 is connected to the third flow portion 310, and the distances between the fourth flow portion 320 and the two second connectors 200 are equal. When the air flow enters the fourth flow portion 320 from the second connector 200 through the third flow portion 310, since the distances between the fourth flow portion 320 and the two second connectors 200 are equal, the air flow enters the fourth flow portion 320 from the third flow portion 310 with equal flow rates, ensuring the uniformity of the air flow in the system.

[0072] Among them, along the flow direction of the air flow in the third flow portion 310, the cross-sectional area of the inner cavity of the third flow portion 310 is larger than the cross-sectional area of the air outlet of the second connector 200. Since the total pressure recovery coefficient of the air flow has been significantly reduced during the process of the air flow entering the second connector 200 from the first flow portion 110, a forced total pressure loss is imposed on the air flow. When the air flow enters the third flow portion 310 from the second connector 200, the cross-sectional area of the third flow portion 310 suddenly increases, continuing to decelerate, expand, and rectify the air flow. The air flow in this section is smooth, the total pressure recovery coefficient is relatively large, and the total pressure of the air flow drops slightly.

[0073] It should be noted that, along the flow direction of the air flow, the ratio of the cross-sectional area of the inner cavity of the third flow portion 310 to the cross-sectional area of the air outlet of the second connector 200 is smaller than the ratio of the cross-sectional area of the inner cavity of the second connector 200 to the cross-sectional area of the inner cavity of the second flow portion 120. With such a setting, compared with the form in which the air flow rapidly expands when entering the second connector 200 from the second flow portion 120, the air flow slowly expands when entering the third flow portion 310 from the second connector 200, making the air flow relatively gentle in this section and slightly decreasing the total pressure of the air flow.

[0074] Preferably in this embodiment, the ratio of the cross-sectional area of the inner cavity of the second connector 200 to the cross-sectional area of the inner cavity of the third flow portion 310 is 4.5π 2 , and the ratio of the cross-sectional area of the inner cavity of the second connector 200 to the cross-sectional area of the inner cavity of the second flow portion 120 is 7π 2 . In several tests, the inventor found that by setting the ratio of the cross-sectional area of the inner cavity of the second connector 200 to the cross-sectional area of the inner cavity of the third flow portion 310 to be 4.5π 2 , and the ratio of the cross-sectional area of the inner cavity of the second connector 200 to the cross-sectional area of the inner cavity of the second flow portion 120 to be 7π 2 , after two forced total pressure losses and flow losses, the total pressure of the air flow can be reduced to an appropriate range to ensure that the thrust-to-weight ratio and the pressure drop ratio at the air source outlet 410 are similar, meeting the conditions for the simulation test of the aircraft.

[0075] In this embodiment, the air outlets of the two second connectors 200 are arranged on the opposite side walls, and the third flow portion 310 is located in the middle of the two second connectors 200. With such a setting, when the third connector 300 is installed on the second connector 200, the forces on the two second connectors 200 are uniform, and thus the loads transmitted to the first connector 100 are uniform, further increasing the structural stability of the simulation device.

[0076] As Figure 5 shown, along the flow direction of the air flow in the fourth flow portion 320, the cross-sectional area of the inner cavity of the fourth connector 400 is larger than the cross-sectional area of the inner cavity of the fourth flow portion 320. When the air flow enters the fourth connector 400 from the fourth flow portion 320, the cross-sectional area of the fourth connector 400 suddenly becomes larger, causing the air flow to decelerate and expand within a relatively small range.

[0077] It should be noted that when the air flow enters the second connecting member 200 through the second flow portion 120, it undergoes a first significant deceleration and pressure increase, and then when it enters the third flow portion 310 from the second connecting member 200, it undergoes a second minor deceleration and pressure increase. When the air flow reaches the fourth connecting member 400, the pressure has dropped significantly. Therefore, the deceleration and pressure increase of the gas when it enters the fourth connecting member 400 from the fourth flow portion 320 are relatively weak.

[0078] In addition, since the gas source outlet 410 is provided at the fourth connecting member 400, in order to ensure that the fourth connecting member 400 can meet the continuous gas outlet requirement, the cross-sectional area of the inner cavity of the fourth connecting member 400 is set to be larger than the cross-sectional area of the inner cavity of the fourth flow portion 320, so that the fourth connecting member 400 can have a larger volume to store a large amount of air flow and meet the continuous and uninterrupted gas outlet requirement of the gas source outlet 410.

[0079] As Figure 5 shown, the distances between several gas source outlets 410 and the third connecting member 300 are equal respectively. By making the distances between several gas source outlets 410 and the third connecting member 300 equal respectively, the air flow entering the fourth connecting member 400 from the fourth flow portion 320 of the third connecting member 300 can be ejected evenly from each gas source outlet 410, ensuring the uniformity of the air flow ejection and better simulating the test of the aircraft.

[0080] In this embodiment, the number of gas source outlets 410 is preferably two. Of course, the number of gas source outlets 410 can also be 2, 3 or more, and this embodiment does not limit this.

[0081] As Figure 1 、 Figure 2 、 Figure 4 and Figure 5 shown, the gas source outlets 410 are respectively connected with Laval nozzles 500 through guide pipes 510. The first half of the Laval nozzle 500 contracts from large to small towards the middle to a narrow throat, and then expands from small to large outwards to the outlet, which can convert the subsonic air flow entering the first connecting member 100 from the gas source inlet 111 into supersonic air flow and eject it to ensure the similarity of jet thrust and the similarity of Mach number at the nozzle outlet, so as to better simulate the test of the aircraft.

[0082] As Figures 6 - 8 shown, a first sealing joint 600 is provided at the rotational connection between the first connecting member 100 and the gas source device. The first sealing joint 600 can increase the airtightness of the connection between the first connecting member 100 and the gas source device and reduce the resistance of the first connecting member 100 to rotate in the first direction.

[0083] Specifically, the first sealing joint 600 includes a first connecting portion 610, a first sealing labyrinth inner ring 620, a first sealing labyrinth outer ring 630, and a first bearing 640. The first connecting portion 610 is fixed to the gas source device, and the first flow portion 110 of the first connecting member 100 is rotatably arranged in the first connecting portion 610 through a bearing, realizing the rotation of the first connecting member 100 in the first direction. Moreover, due to the presence of the first bearing 640, the friction force when the first connecting member 100 rotates in the first direction can be effectively reduced.

[0084] The first sealing labyrinth inner ring 620 is sleeved on the first flow portion 110, the first sealing labyrinth outer ring 630 is arranged in the first connecting portion 610, and the facing end faces of the first sealing labyrinth outer ring 630 and the first sealing labyrinth inner ring 620 alternately form a labyrinth seal, which can effectively prevent air leakage.

[0085] As Figure 6 、 Figure 7 and Figure 9 shown, a second sealing joint 700 is provided at the rotational connection between the second connecting member 200 and the first connecting member 100. The second sealing joint 700 can increase the airtightness of the connection between the second connecting member 200 and the first connecting member 100, and reduce the resistance of the second connecting member 200 when rotating in the second direction.

[0086] Specifically, the second sealing joint 700 includes a second sealing labyrinth inner ring 710, a second sealing labyrinth outer ring 720, and a second bearing 730. The second sealing labyrinth inner ring 710 is sleeved on the second flow portion 120 of the first connecting member 100, the second sealing labyrinth outer ring 720 is arranged on the second connecting member 200, and the facing end faces of the second sealing labyrinth inner ring 710 and the second sealing labyrinth outer ring 720 alternately form a labyrinth seal, which can effectively prevent air leakage.

[0087] There is a gap between the inner wall of the second sealing labyrinth outer ring 720 and the outer wall of the second flow portion 120. This gap is used to install the second bearing 730, and the second bearing 730 is sleeved on the second flow portion 120 to realize the rotational connection between the second connecting member 200 and the first connecting member 100 in the second direction. Moreover, due to the presence of the second bearing 730, the friction force when the second connecting member 200 rotates in the second direction can be effectively reduced.

[0088] As Figure 6 、 Figure 10 and Figure 11 shown, a third sealing joint 800 is provided at the rotational connection between the fourth connecting member 400 and the third connecting member 300. The third sealing joint 800 can increase the airtightness of the connection between the fourth connecting member 400 and the third connecting member 300, and reduce the resistance of the fourth connecting member 400 when rotating in the third direction.

[0089] Specifically, the third sealing joint 800 includes a third sealing labyrinth inner ring 810, a third sealing labyrinth outer ring 820, and a third bearing 830. The third sealing labyrinth inner ring 810 is sleeved on the fourth flow portion 320 of the third connecting member 300. The third sealing labyrinth outer ring 820 is disposed on the fourth connecting member 400. Opposite end faces of the third sealing labyrinth inner ring 810 and the third sealing labyrinth outer ring 820 alternately form a labyrinth seal, which can effectively prevent air leakage.

[0090] There is a gap between the inner wall of the third sealing labyrinth outer ring 820 and the outer wall of the fourth flow portion 320. This gap is used to install the third bearing 830, and the third bearing 830 is sleeved on the fourth flow portion 320 to realize the rotational connection of the fourth connecting member 400 with the third connecting member 300 in the third direction. Moreover, due to the presence of the third bearing 830, the friction force when the fourth connecting member 400 rotates in the third direction can be effectively reduced.

[0091] It should be noted that in this article, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device including a series of elements not only includes those elements but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "including a..." does not exclude the presence of additional identical elements in the process, method, article or device including such element.

[0092] In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed. It may also include performing functions in a substantially simultaneous manner or in a reverse order according to the functions involved. For example, the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0093] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention.

Claims

1. A wind tunnel virtual flight test dynamic similarity simulation device, characterized in that: include: A first connecting member is rotatably arranged on the gas source device along a first direction; A second connecting member, rotatably disposed on the first connecting member along a second direction; a third connecting member connected to the second connecting member; A fourth connecting member, rotatably disposed on the third connecting member along a third direction; The first connecting piece has a plurality of gas source inlets, the fourth connecting piece has a plurality of gas source outlets, the gas flow enters from the gas source inlets, flows along the first connecting piece, the second connecting piece, the third connecting piece and the fourth connecting piece, and is discharged from the gas source outlets; Wherein, along the flow direction of the airflow in the first connecting member, the cross-sectional area of ​​the inner cavity of the second connecting member is larger than the cross-sectional area of ​​the inner cavity of the first connecting member.

2. A wind tunnel virtual flight test dynamic similarity simulation device according to claim 1, characterized in that: The first connecting member has a first flow portion and a second flow portion, and there are two second connecting members; One end of the first flow part is provided with the gas source inlet, and the other end is connected to the second flow part; the two gas outlets of the second flow part are respectively connected to the gas inlets of the two second connecting members; Wherein, along the flow direction of the airflow in the second flow portion, the cross-sectional area of ​​the inner cavity of the second connecting member is larger than the cross-sectional area of ​​the inner cavity of the second flow portion.

3. A wind tunnel virtual flight test dynamic similarity simulation device according to claim 2, characterized in that: The third connecting member has a third flow portion and a fourth flow portion; The third flow portion is connected to the fourth flow portion, and two air inlets of the third flow portion are respectively connected to two air outlets of the second connecting members.

4. A wind tunnel virtual flight test dynamic similarity simulation device according to claim 3, characterized in that: The second flow portion and the third flow portion are respectively located between the two second connecting members; The distance between the first flow portion and the two second connecting members is equal, and the distance between the fourth flow portion and the two second connecting members is equal.

5. The wind tunnel virtual flight test dynamic similarity simulation device according to claim 2, characterized in that: Along the flow direction of the airflow in the first flow portion, the cross-sectional area of ​​the inner cavity of the second flow portion is larger than the cross-sectional area of ​​the inner cavity of the first flow portion.

6. The wind tunnel virtual flight test dynamic similarity simulation device according to claim 3, characterized in that: Along the flow direction of the airflow in the fourth flow portion, the cross-sectional area of ​​the inner cavity of the fourth connecting member is larger than the cross-sectional area of ​​the inner cavity of the fourth flow portion.

7. The wind tunnel virtual flight test dynamic similarity simulation device according to claim 3 is characterized in that: Along the flow direction of the airflow in the third flow portion, the cross-sectional area of ​​the inner cavity of the third flow portion is larger than the cross-sectional area of ​​the air outlet of the second connecting member.

8. The wind tunnel virtual flight test dynamic similarity simulation device according to claim 7, characterized in that: Along the flow direction of the airflow, the ratio of the cross-sectional area of ​​the inner cavity of the third flow portion to the cross-sectional area of ​​the air outlet of the second connecting member is smaller than the ratio of the cross-sectional area of ​​the inner cavity of the second connecting member to the cross-sectional area of ​​the inner cavity of the second flow portion.

9. The wind tunnel virtual flight test dynamic similarity simulation device according to claim 1, characterized in that: The distances between the plurality of gas source outlets and the third connecting member are respectively equal.

10. A wind tunnel virtual flight test dynamic similarity simulation device according to claim 1 or 9, characterized in that: A plurality of gas source outlets are respectively connected to Laval nozzles through flow guide pipes.

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