A new air bridge device with calibration-free function

Abstract

A novel air bridge device with a calibration-free function belongs to the technical field of aircraft power simulation tests. In order to solve the problem that the air bridge is damaged or its relative position with the balance changes during the test, the present invention must re-complete the full-process calibration to obtain the interference force on the balance. The first straight pipe, the second straight pipe, the L-shaped bend pipe and the third straight pipe are connected end to end in sequence, and elastic ventilation devices are provided at the interfaces between the first straight pipe and the second straight pipe, between the second straight pipe and the L-shaped bend pipe, and between the L-shaped bend pipe and the third straight pipe. The upper end of the first straight pipe is connected to the measuring end of the balance, the right end of the third straight pipe is connected to the fixed end of the balance, and the axis of the third straight pipe is perpendicular to the axis of the first straight pipe and the second straight pipe. The novel air bridge device with a calibration-free function of the present invention can quickly obtain the interference force on the balance without performing the overall calibration of the air bridge and the combined calibration with the balance.

Description

Technical Field

[0001] The present invention relates to an air bridge, in particular to a novel air bridge device with a calibration-free function, belonging to the technical field of aircraft power simulation tests. Background Art

[0002] Aircraft power system simulation testing (power simulation testing) is an essential step in the development of aerospace vehicles. These tests primarily include nozzle performance testing, wind tunnel testing to determine the impact of jet flow on overall aircraft aerodynamic characteristics, propeller slipstream testing, and civil aircraft turbine power simulator (TPS) wind tunnel testing. These tests all directly or indirectly require high-pressure air for dynamic simulation. For example, high-pressure air can directly generate the jet flow, high-pressure air can drive a turbine power simulator to generate an external jet flow, and high-pressure air can drive an air motor to generate a propeller slipstream. Therefore, these tests or research share a common characteristic: they require both high-pressure air supply lines to the model and a multi-component balance to measure the model's aerodynamic forces. The high-pressure air supply lines can affect the balance measurements. Therefore, appropriate technical measures must be employed to isolate the air supply line's receiving end (the balance's measuring end) from the air supply end (the balance's fixed end) to improve the balance's measurement accuracy.

[0003] An air bridge is a flexible connection in a high-pressure air transmission pipeline that can isolate the air supply end and the air receiving end to reduce or eliminate the mechanical influence of the air supply end pipeline. It is also called an "air transfer device" or "decoupling device". It is a key component in aircraft power simulation aerodynamic test and research equipment. ZL200720078356 discloses an air bridge device with a "U"-shaped layout, which has six degrees of freedom and achieves a strong interference cancellation capability. However, the current air bridge device must undergo a calibration process with a huge workload, cumbersome procedures and a very long cycle before use. Application publication number CN201810183486 discloses a calibration method for a wind tunnel strain balance with an air bridge that takes into account the influence of pressure. It has been shown that the calibration process is complicated, which will greatly affect the test efficiency.

[0004] In addition, if the air bridge is damaged or its relative position to the balance changes during the test, the entire process must be recalibrated and the test must be suspended.

[0005] Therefore, proposing a calibration-free air bridge device can greatly improve the efficiency and quality of power simulation tests, which is of great significance to the improvement of aircraft power simulation test technology. Summary of the Invention

[0006] The purpose of the present invention is to provide a new air bridge device with a calibration-free function to solve the problem that if the air bridge is damaged or its relative position with the balance changes during the test, the whole process calibration must be completed again to obtain the interference force on the balance.

[0007] A novel air bridge device with a calibration-free function includes an L-shaped elastic tube;

[0008] The L-shaped elastic pipeline includes an elastic venting device, a first straight pipeline, a second straight pipeline, an L-shaped elbow and a third straight pipeline;

[0009] The first straight pipe, the second straight pipe, the L-shaped elbow and the third straight pipe are connected end to end in sequence, and elastic ventilation devices are provided at the interfaces between the first straight pipe and the second straight pipe, between the second straight pipe and the L-shaped elbow, and between the L-shaped elbow and the third straight pipe. The upper end of the first straight pipe is connected to the measuring end of the balance, the right end of the third straight pipe is connected to the fixed end of the balance, and the axis of the third straight pipe is perpendicular to the axes of the first straight pipe and the second straight pipe.

[0010] Preferably: the elastic vent device comprises a bellows flange, a bellows, a cross nut and a strain gauge;

[0011] Bellows flanges are provided at both ends of the bellows, and the two bellows flanges are respectively connected to the two ends of a cross nut, on which a plurality of strain gauges are provided.

[0012] Preferably, the cross-section includes three cross-sectional rings, a pair of strain beams is provided between two adjacent cross-sectional rings, the axes of the two pairs of strain beams are perpendicular to each other, strain gauges are provided on the strain beams, and the cross-sectional rings at the upper and lower end faces of the cross-section can achieve relative rotational freedom through the bending deformation of the strain beams.

[0013] Preferably, it also includes a balance measuring end, a balance strain beam and a balance fixed end, both ends of the balance measuring end are connected to the two ends of the balance fixed end through the balance strain beam, one end of the L-shaped elastic pipe is connected to the balance measuring end, and the other end of the L-shaped elastic pipe is connected to the balance fixed end.

[0014] Compared with existing products, the present invention has the following effects:

[0015] The present invention proposes a new air bridge device with a calibration-free function. It utilizes strain measurement technology and combines it with a combined force solution method. It only needs to perform theoretical calculations and basic calibration tests on a separate elastic ventilation structure, thereby eliminating the need for overall calibration of the air bridge and calibration in combination with a balance. Ultimately, a calibration-free air bridge is realized, which greatly reduces the calibration work incidental to the use of air bridge technology and greatly improves its efficiency.

[0016] The interference force on the balance can be quickly obtained without performing overall calibration of the air bridge and combined calibration with the balance. When an abnormality occurs on the air bridge balance during the test, the test delay period of 2 to 3 months of wind tunnel test needs to be reduced to 2 days, and the additional calibration workload of 1 to 2 months can be reduced to zero, which can greatly improve the efficiency of wind tunnel tests and reduce indirect costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural diagram of a new air bridge device with calibration-free function;

[0018] Figure 2 is a schematic structural diagram of an elastic venting device;

[0019] Figure 3 yes Figure 2 The main view;

[0020] Figure 4 is a schematic diagram of the three-dimensional coordinates of the elastic ventilation device;

[0021] Figure 5 yes Figure 4 The main view;

[0022] Figure 6 It is a schematic diagram of the structure of ten bytes;

[0023] Figure 7 yes Figure 6 The main view;

[0024] Figure 8 is a schematic diagram of elastic deformation of the elastic ventilation device;

[0025] Figure 9 This is a schematic diagram of a new air bridge device with calibration-free function applied to a strain gauge balance.

[0026] In the figure, 1-elastic ventilation device, 2-first straight pipe, 3-second straight pipe, 4-L-shaped elbow, 5-third straight pipe, 6-bellows flange, 7-bellows, 8-cross bit, 9-strain beam, 10-strain gauge, 11-z coordinate axis, 12-x coordinate axis, 13-y coordinate axis, 14-connecting pipe, 15-lateral displacement, 16-interference force, 201-balance measuring end, 202-balance strain beam, 203-balance fixed end, 911-first strain beam, 912-second strain beam, 921-third strain beam, 922-fourth strain beam. DETAILED DESCRIPTION

[0027] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0028] Combine Figures 1 to 3As shown, this embodiment discloses a novel air bridge device with a calibration-free function, comprising an L-shaped elastic pipe;

[0029] The L-shaped elastic pipeline includes an elastic venting device 1, a first straight pipeline 2, a second straight pipeline 3, an L-shaped elbow 4 and a third straight pipeline 5;

[0030] The first straight pipeline 2, the second straight pipeline 3, the L-shaped elbow 4 and the third straight pipeline 5 are connected end to end in sequence, and elastic ventilation devices 1 are provided at the interfaces between the first straight pipeline 2 and the second straight pipeline 3, between the second straight pipeline 3 and the L-shaped elbow 4, and between the L-shaped elbow 4 and the third straight pipeline 5. The upper end of the first straight pipeline 2 is connected to the measuring end 201 of the balance, the right end of the third straight pipeline 5 is connected to the fixed end 203 of the balance, and the axis of the third straight pipeline 5 is perpendicular to the axes of the first straight pipeline 2 and the second straight pipeline 3.

[0031] Further: the elastic vent device 1 includes a bellows flange 6, a bellows 7, a cross head 8 and a strain gauge 10;

[0032] Bellows flanges 6 are provided at both ends of the bellows 7 , and the two bellows flanges 6 are respectively connected to the two ends of a cross 8 , on which a plurality of strain gauges 10 are provided.

[0033] Further: the cross-section 8 includes three cross-sectional rings, and a pair of strain beams 9 is provided between two adjacent cross-sectional rings. The axes of the two pairs of strain beams 9 are perpendicular to each other, and the strain gauges 10 are provided on the strain beams 9. The cross-sectional rings at the upper and lower end faces of the cross-section can achieve relative rotational freedom through the bending deformation of the strain beams 9.

[0034] Further: Figure 9 As shown, it also includes a balance measuring end 201, a balance strain beam 202 and a balance fixed end 203. Both ends of the balance measuring end 201 are connected to both ends of the balance fixed end 203 through the balance strain beam 202. One end of the L-shaped elastic pipe is connected to the balance measuring end 201, and the other end of the L-shaped elastic pipe is connected to the balance fixed end 203.

[0035] like Figure 4 and Figure 5 As shown, a novel air bridge device with calibration-free functionality is used in aircraft dynamics simulation test systems that combine an aerodynamic balance to measure aerodynamic forces with a high-pressure air supply, minimizing interference with balance measurements. The bellows elastic element employed in the device offers tensile and compressive degrees of freedom along the central axial z-axis 11, as well as rotational degrees of freedom about the transverse x-axis 12 and transverse y-axis 13. The crossbar, due to the provision of elastic beams, also offers rotational degrees of freedom about the transverse x-axis 12 and transverse y-axis 13.

[0036] like Figure 6 、7 As shown in Figures 8 and 9 , when a separate elastic ventilation structure 1 is subjected to a lateral displacement 15 caused by the elastic deformation of the end of the connecting pipe 14 along with the balance, where the connecting pipe 14 refers to any one of the first straight pipe 2, the second straight pipe 3, or the third straight pipe 5, a corresponding lateral interference force 16 will be generated. At this time, the first strain beam 911 and the second strain beam 912 on the elastic ventilation structure in the direction perpendicular to the coordinate axis 13 of the lateral displacement 15 will undergo a certain degree of bending deformation, so that only a small lateral interference force 16 is generated under the action of the lateral displacement 15. For the elastic beam 9 with the strain gauge 10 attached, the strain sensed by the strain gauge 10 is proportional to the interference force 16. The proportional relationship between the strain and the interference force on the elastic ventilation structure 1 needs to be calibrated in advance, after which the lateral interference force 16 under the action of the lateral displacement 15 can be directly measured by the strain gauge 10 to obtain the strain of the elastic beam 9.

[0037] like Figure 6 、 7 As shown in Figures 9 and 10, for the entire L-shaped air bridge, the L-shaped long-side pipe end 2 is connected to the measuring end 201 of the balance, and the L-shaped short-side pipe end 5 is connected to the fixed end 203 of the balance. When the balance is subjected to a load, its strain beam 202 will undergo a certain "S"-shaped deformation, for example, a lateral displacement 301. At this time, the L-shaped long-side pipe end 2 simultaneously undergoes a lateral displacement 301 along with the measuring end 201 of the balance. The elastic beams 911 and 912 of the first and second elastic vent structures will undergo a certain bending deformation, and the straight pipe 3 will undergo rotational displacement. However, the elastic beam 9 of the third elastic vent structure will not undergo significant deformation. By calibrating the relationship between the strain and the corresponding interference force of each elastic vent structure, the interference force of each elastic vent structure can be measured separately. Furthermore, by combining and solving the interference forces of each elastic vent structure, the interference force on the balance caused by the lateral displacement 301 of the L-shaped long-side pipe end 2 or the L-shaped short-side pipe end 5 of the air bridge can be obtained.

[0038] This embodiment is only an illustrative description of this patent and does not limit its scope of protection. Those skilled in the art may also make partial changes to it. As long as it does not exceed the spirit of this patent, it is within the scope of protection of this patent.

Claims

1. A novel air bridge device with calibration-free function, characterized by: Including L-shaped elastic pipe; The L-shaped elastic pipeline comprises an elastic venting device (1), a first straight pipeline (2), a second straight pipeline (3), an L-shaped elbow (4) and a third straight pipeline (5); The first straight pipe (2), the second straight pipe (3), the L-shaped elbow (4) and the third straight pipe (5) are connected end to end in sequence, and elastic ventilation devices (1) are provided at the interfaces between the first straight pipe (2) and the second straight pipe (3), between the second straight pipe (3) and the L-shaped elbow (4), and between the L-shaped elbow (4) and the third straight pipe (5). The upper end of the first straight pipe (2) is connected to the measuring end (201) of the balance, the right end of the third straight pipe (5) is connected to the fixed end (203) of the balance, and the axis of the third straight pipe (5) is perpendicular to the axes of the first straight pipe (2) and the second straight pipe (3); The elastic venting device (1) comprises a bellows flange (6), a bellows (7), a cross-head (8) and a strain gauge (10); Both ends of the bellows (7) are provided with bellows flanges (6), and the two bellows flanges (6) are respectively connected to the two ends of the cross nut (8), and the cross nut (8) is provided with a plurality of strain gauges (10).

2. The novel air bridge device with calibration-free function according to claim 1, characterized in that: The cross-section ring (8) comprises three cross-section rings, a pair of strain beams (9) is provided between two adjacent cross-section rings, the axes of the two pairs of strain beams (9) are perpendicular to each other, strain gauges (10) are provided on the strain beams (9), and the cross-section rings at the upper and lower end faces of the cross-section ring can achieve relative rotational freedom through the bending deformation of the strain beams (9).

3. The novel air bridge device with calibration-free function according to claim 1, characterized in that: It also includes a balance measuring end (201), a balance strain beam (202) and a balance fixed end (203), wherein both ends of the balance measuring end (201) are connected to both ends of the balance fixed end (203) via the balance strain beam (202).

Images