Wind tunnel virtual flight test dynamic analog simulation device

Abstract

The invention relates to the technical field of wind tunnel dynamic simulation, and discloses a wind tunnel virtual flight test dynamic similar simulation device, which comprises a first connecting piece, a second connecting piece and a third connecting piece, the second connecting piece is rotationally arranged on the first connecting piece in the second direction; the third connecting piece is connected with the second connecting piece; the fourth connecting piece is rotationally arranged on the third connecting piece in the third direction; the first connecting piece is provided with a plurality of air source inlets, the fourth connecting piece is provided with a plurality of air source outlets, and airflow enters from the air 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 air source outlets; in the flowing direction of the airflow, the cross section area of the inner cavity of the second connecting piece is larger than that of the inner cavity of the first connecting piece. By means of the method, the technical problem that it is difficult to simulate the thrust-weight ratio and the drop pressure ratio on the scale model at the same time in a wind tunnel simulation aircraft test in the related technology is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of wind tunnel power simulation, and particularly to a power similarity simulation device for virtual flight tests in a wind tunnel. 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 active disturbance rejection control, dynamic inversion, and reconfiguration control, there is an urgent need for a power similarity device that can simultaneously simulate the thrust-to-weight ratio and the pressure ratio reduction 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 power similarity simulation device for virtual flight tests in a wind tunnel that can simultaneously simulate the thrust-to-weight ratio and the pressure ratio reduction 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 power similarity simulation device for virtual flight tests in a wind tunnel to solve the technical problem that it is difficult to simultaneously simulate the thrust-to-weight ratio and the pressure ratio reduction 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: A power similarity simulation device for virtual flight tests in a wind tunnel, comprising: A first connecting member rotatably arranged on a gas source device in a first direction; A second connecting member rotatably arranged on the first connecting member in a second direction; A third connecting member connected to the second connecting member; A fourth connecting member rotatably arranged on the third connecting member in 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 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.

[0006] In some solutions, 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 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 connecting members; Among them, along the flow direction of the air flow in the second flow part, the cross-sectional area of the inner cavity of the second connecting piece is larger than the cross-sectional area of the inner cavity of the second flow part.

[0007] In some solutions, the third connecting piece has a third flow part and a fourth flow part; The third flow part is connected to the fourth flow part, and the two air inlets of the third flow part are respectively connected to the air outlets of the two second connecting pieces.

[0008] In some solutions, the second flow part and the third flow part are respectively located between the two second connecting pieces; The distances between the first flow part and the two second connecting pieces are equal, and the distances between the fourth flow part and the two second connecting pieces are equal.

[0009] In some solutions, along the flow direction of the air flow in the first flow part, the cross-sectional area of the inner cavity of the second flow part is larger than the cross-sectional area of the inner cavity of the first flow part.

[0010] In some solutions, along the flow direction of the air flow in the fourth flow part, the cross-sectional area of the inner cavity of the fourth connecting piece is larger than the cross-sectional area of the inner cavity of the fourth flow part.

[0011] In some solutions, along the flow direction of the air flow in the third flow part, the cross-sectional area of the inner cavity of the third flow part is larger than the cross-sectional area of the air outlet of the second connecting piece.

[0012] In some solutions, along the flow direction of the air flow, the ratio of the cross-sectional area of the inner cavity of the third flow part to the cross-sectional area of the air outlet of the second connecting piece is smaller than the ratio of the cross-sectional area of the inner cavity of the second connecting piece to the cross-sectional area of the inner cavity of the second flow part.

[0013] In some solutions, the distances between several air source outlets and the third connecting piece are respectively equal.

[0014] In some solutions, several air source outlets are respectively connected with Laval nozzles through diversion pipes.

[0015] The technical solution adopted by the present invention can achieve the following beneficial effects: In the dynamic similarity simulation device for wind tunnel virtual flight tests of this application, during tests on aircraft, airflows enter from the air source inlet and flow along the first connecting piece, the second connecting piece, the third connecting piece, and the fourth connecting piece, and are discharged from the air source outlet. When the airflows enter from the first connecting piece into the second connecting piece, the cross-sectional area suddenly becomes larger, causing the airflows to form in-tube shock waves here and rapidly decelerate and expand, converting the kinetic energy of the airflows 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, further significantly reducing the total pressure recovery coefficient of the airflows, imposing forced total pressure losses on the airflows, and reducing the total pressure of the airflows to an appropriate range to meet the simulation test requirements for the simultaneous similarity of the thrust-to-weight ratio and the pressure drop ratio of the aircraft. Moreover, the first connecting piece can rotate in the first direction, the second connecting piece can rotate in the second direction, and the fourth connecting piece can rotate in the third direction, enabling this simulation device to have three degrees of freedom of angular motion and further meeting the simulation test requirements of the aircraft. Brief Description of the Drawings

[0016] 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 following-described drawings 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.

[0017] Figure 1 is the axonometric view of the dynamic similarity simulation device for wind tunnel virtual flight tests of the present invention; Figure 2 is the top view of the dynamic similarity simulation device for wind tunnel virtual flight tests of the present invention; Figure 3 is Figure 2 the sectional view of the A-A plane in Figure 4 is the front view of the dynamic similarity simulation device for wind tunnel virtual flight tests of the present invention Figure 1 ; Figure 5 is Figure 4 the sectional view of the B-B plane in Figure 6 is the front view of the dynamic similarity simulation device for wind tunnel virtual flight tests of the present invention Figure 2 ; Figure 7 is Figure 6 the sectional view of the C-C plane in Figure 8 is Figure 7 the enlarged view at E in Figure 9 is Figure 7 the enlarged view at F in Figure 10 isFigure 6 Cross-sectional view of plane D-D; Figure 11 is Figure 10 Enlarged view at position G in the figure.

[0018] In the figure: 100 - First connecting member, 110 - First flow portion, 111 - Gas source inlet, 120 - Second flow portion; 200 - Second connecting member; 300 - Third connecting member, 310 - Third flow portion, 320 - Fourth flow portion; 400 - Fourth connecting member, 410 - Gas source outlet; 500 - Laval nozzle, 510 - Duct; 600 - First sealing joint, 610 - First connecting portion, 620 - Inner ring of first sealing labyrinth teeth, 630 - Outer ring of first sealing labyrinth teeth, 640 - First bearing; 700 - Second sealing joint, 710 - Inner ring of second sealing labyrinth teeth, 720 - Outer ring of second sealing labyrinth teeth, 730 - Second bearing; 800 - Third sealing joint, 810 - Inner ring of third sealing labyrinth teeth, 820 - Outer ring of third sealing labyrinth teeth, 830 - Third bearing. Detailed implementation mode

[0019] 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 fall within the scope of protection of the present invention.

[0020] 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 such used data 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 generally of the same category, and do not limit the number of objects. For example, the first object can be one or multiple. 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.

[0021] During the process of the inventor using a wind tunnel to test an aircraft, it was found that due to the widespread adoption of unconventional aerodynamic configurations in recent years, the aircraft exhibits new non-linear characteristics, and its 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 reconfigurable control, in the early design stage, if a wind tunnel device is used to test the aircraft, the cost is high and the efficiency is low.

[0022] 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 the present application will be described in detail.

[0023] As Figure 1 , Figure 2 and Figure 4 shown, a dynamic similarity simulation device for wind tunnel virtual flight tests includes a first connecting member 100, a second connecting member 200, a third connecting member 300, a fourth connecting member 400, a guide pipe 510, and a Laval nozzle 500.

[0024] As Figure 1 shown, the first connecting member 100 is rotatably arranged on the gas source device in the first direction, the second connecting member 200 is rotatably arranged on the first connecting member 100 in the second direction, the third connecting member 300 is connected to the second connecting member 200, and the fourth connecting member 400 is rotatably arranged on the third connecting member 300 in the third direction.

[0025] When an 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.

[0026] The rotation of the first connecting member 100 in the first direction is used for yaw simulation tests, and it can simulate the yaw conditions of the aircraft under conditions such as crosswind, downwind, or upwind, 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, and it can simulate the pitch moment changes encountered by the aircraft during different climb or descent 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 actions such as turning or rolling, so as to evaluate the performance of its roll control system.

[0027] 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 .

[0028] As Figure 3 and Figure 5 shown, the first connector 100, the second connector 200, the third connector 300 and the fourth connector 400 respectively have inner cavities, and the first connector 100 has a plurality of air source inlets 111, and the fourth connector 400 has a plurality of air source outlets 410. The air flow enters from the air source inlet 111, flows along the first connector 100, the second connector 200, the third connector 300 and the fourth connector 400, and is discharged from the air source outlet 410, simulating the air flow conditions encountered by the aircraft during actual flight.

[0029] As Figure 3 and Figure 5 shown, along the flow direction of the air flow in the first connector 100, 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 first connector 100.

[0030] When the air flow enters from the first connector 100 into the second connector 200, the cross-sectional area of the second connector 200 suddenly becomes larger, causing the air flow to form an internal shock wave here and quickly decelerate and expand, converting the kinetic energy of the air flow into pressure energy, and at the same time accompanied by frictional losses, eddy current losses, etc., resulting in a decrease in the total pressure at the outlet of the system, and then significantly reducing the total pressure recovery coefficient of the air flow, imposing a forced total pressure loss on 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.

[0031] As Figure 3 and Figure 5 shown, the first connector 100 has a first flow portion 110 and a second flow portion 120. Specifically, the air source inlet 111 is provided 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.

[0032] Both the first flow portion 110 and the second flow portion 120 have inner cavities that penetrate along their respective axes, and the air source inlet 111 is provided at the end of the first flow portion 110. The air flow enters the first flow portion 110 from the air source inlet 111 and then enters the second flow portion 120. When the air flow enters from the first flow portion 110 into the second flow portion 120, the cross-sectional area of the second flow portion 120 suddenly becomes larger, and the air flow will also have a certain degree of deceleration and expansion here, reducing the total pressure recovery coefficient of the air flow within a certain range and imposing a forced total pressure loss on the air flow.

[0033] 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.

[0034] As Figures 1 - 3 andFigure 5 As shown, there are two second connectors 200, and the second flow portions 120 are respectively connected to the air inlets of the second connectors 200. Specifically, along the flow direction of the air flow in the second flow portions 120, the cross-sectional area of the inner cavity of the second connectors 200 is larger than the cross-sectional area of the inner cavity of the second flow portions 120.

[0035] When the air flow enters the second connectors 200 from the second flow portions 120, the cross-sectional area of the second connectors 200 suddenly becomes larger, causing the air flow to form an in-tube shock wave here and quickly decelerate and compress. The kinetic energy of the air flow 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, and then significantly reducing 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.

[0036] In this embodiment, the air inlets of the two second connectors 200 are arranged on the opposite side walls, and the second flow portions 120 are 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.

[0037] 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 decelerating and compressing the air flow, and the second flow portion 120 mainly undertakes the task of conducting the pitch simulation test.

[0038] In this embodiment, the middle parts of the first flow portion 110 and the second flow portion 120 are connected, 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 enters the second connectors 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.

[0039] 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, and one end of the fourth flow portion 320 is vertically connected to the middle of the third flow portion 310 to form a T-shaped structure, and the other end is rotatably connected to the fourth connector 400.

[0040] Both the third flow portion 310 and the fourth flow portion 320 have an inner cavity that penetrates along their own axial directions. The air flow discharged from the second connector 200 enters the third flow portion 310 and then enters the fourth connector 400 through the fourth flow portion 320. 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 roll simulation test.

[0041] In this embodiment, the fourth flow portion 320 is connected to the middle of 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, due to the equal distances between the fourth flow portion 320 and the two second connectors 200, the flow rates of the air flow entering the fourth flow portion 320 from the third flow portion 310 are equal, ensuring the uniformity of the air flow in the system.

[0042] 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 decreases slightly.

[0043] 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 expands extremely rapidly when entering the second connector 200 from the second flow portion 120, the air flow expands slowly when entering the third flow portion 310 from the second connector 200, making the air flow relatively smooth in this section and slightly decreasing the total pressure of the air flow.

[0044] 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, the ratio of the cross-sectional area of the inner cavity of the second connecting member 200 to the cross-sectional area of the inner cavity of the second flow portion 120 is 7π 2 , through two forced total pressure losses and flow losses, the total pressure of the air flow can be reduced to an appropriate range to ensure the similarity of the thrust-to-weight ratio and the pressure drop ratio at the air source outlet 410, meeting the conditions for the simulation test of the aircraft.

[0045] In this embodiment, the air outlets of the two second connecting members 200 are arranged on the opposite side walls, and the third flow portion 310 is located between the two second connecting members 200. With this arrangement, when the third connecting member 300 is installed on the second connecting member 200, the forces on the two second connecting members 200 are uniform, and thus the loads transmitted to the first connecting member 100 are uniform, further increasing the structural stability of the simulation device.

[0046] 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 connecting member 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 connecting member 400 from the fourth flow portion 320, the cross-sectional area of the fourth connecting member 400 suddenly becomes larger, causing the air flow to decelerate and expand in a relatively small range here.

[0047] It should be noted that since the air flow undergoes a large-scale deceleration and expansion for the first time when passing through the second flow portion 120 and entering the second connecting member 200, and then undergoes a small-scale deceleration and expansion for the second time when entering the third flow portion 310 from the second connecting member 200. When the air flow reaches the fourth connecting member 400, the pressure has dropped significantly. Therefore, the deceleration and expansion of the gas when entering the fourth connecting member 400 from the fourth flow portion 320 are relatively weak.

[0048] In addition, since the air 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 air outlet requirements, therefore, 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, meeting the continuous and uninterrupted air outlet requirements of the air source outlet 410.

[0049] As Figure 5 shown, the distances between several air source outlets 410 and the third connecting member 300 are equal respectively. By making the distances between several air 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 air source outlet 410, ensuring the uniformity of the air flow injection, so as to better simulate the aircraft.

[0050] In this embodiment, the number of gas source outlets 410 is preferably two. It goes without saying that the number of gas source outlets 410 can also be two, three or more, and this embodiment does not limit this.

[0051] As Figure 1 , Figure 2 , Figure 4 and Figure 5 shown, the gas source outlets 410 are respectively connected with Laval nozzles 500 through diversion pipes 510. The first half of the Laval nozzle 500 shrinks 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 airflow entering the first connector 100 from the gas source inlet 111 into supersonic airflow and eject it, so as to ensure the similarity of jet thrust and the similarity of Mach number at the nozzle, and better conduct simulation tests on the aircraft.

[0052] As Figures 6 - 8 shown, a first sealing joint 600 is provided at the rotational connection between the first connector 100 and the gas source device. The first sealing joint 600 can increase the airtightness of the connection between the first connector 100 and the gas source device, and reduce the resistance of the first connector 100 to rotate in the first direction.

[0053] 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 on the gas source device, and the first flow portion 110 of the first connector 100 is rotatably arranged in the first connecting portion 610 through a bearing, realizing the rotation of the first connector 100 in the first direction. And, due to the existence of the first bearing 640, the friction force when the first connector 100 rotates in the first direction can be effectively reduced.

[0054] 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.

[0055] As Figure 6 , Figure 7 and Figure 9 shown, a second sealing joint 700 is provided at the rotational connection between the second connector 200 and the first connector 100. The second sealing joint 700 can increase the airtightness of the connection between the second connector 200 and the first connector 100, and reduce the resistance of the second connector 200 to rotate in the second direction.

[0056] 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 connector 100. The second sealing labyrinth outer ring 720 is disposed on the second connector 200. The opposing 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.

[0057] 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 achieve the rotational connection of the second connector 200 with the first connector 100 in the second direction. Moreover, due to the presence of the second bearing 730, the frictional force when the second connector 200 rotates in the second direction can be effectively reduced.

[0058] As Figure 6 、 Figure 10 and Figure 11 shown, at the rotational connection of the fourth connector 400 and the third connector 300, a third sealing joint 800 is provided. The third sealing joint 800 can increase the airtightness of the connection between the fourth connector 400 and the third connector 300, and reduce the resistance when the fourth connector 400 rotates in the third direction.

[0059] 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 connector 300. The third sealing labyrinth outer ring 820 is disposed on the fourth connector 400. The opposing 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.

[0060] 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 achieve the rotational connection of the fourth connector 400 with the third connector 300 in the third direction. Moreover, due to the presence of the third bearing 830, the frictional force when the fourth connector 400 rotates in the third direction can be effectively reduced.

[0061] It should be noted that, in this document, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device that includes a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the presence of additional identical elements in the process, method, article or device that includes such element.

[0062] 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, and may also include performing functions in a substantially simultaneous manner or in the reverse order according to the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, the features described with reference to certain examples may be combined in other examples.

[0063] As described above, the above are only specific embodiments 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. A 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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