Integrated structure, design method and assembly method of air bridge balance air inlet and return system

Abstract

The integrated structure, design method and assembly method of the air bridge balance air inlet and return system belong to the field of wind tunnel test technology. The present invention solves the problem of wind tunnel model structure design caused by the difficulty in overall layout of the air bridge balance air inlet and return system due to insufficient model space. The two high-pressure air inlet pipes and two low-pressure air return pipes of the air bridge pipeline of the present invention are embedded in the fuselage load-bearing parts in the form of a gooseneck air bridge layout. The high-pressure air inlet pipe is connected to the flow control unit, and the flow control unit is connected to the ventilation wing. The ventilation wing is connected to the low-pressure air return pipe, and the high-pressure air inlet pipe, the low-pressure air return pipe and the internal strain balance are respectively connected to the support. The integrated structure, design method and assembly method of the air bridge balance air inlet and return system of the present invention can significantly improve the technical capabilities of the TPS nacelle and air motor driven propeller and other power simulation wind tunnel tests, and play an important role in improving the applicability and reliability of the air bridge air inlet and return system.

Description

Technical Field

[0001] The invention belongs to the technical field of wind tunnel testing, and in particular relates to an integrated structure, a design method and an assembly method of an air bridge balance air inlet and return system. Background Art

[0002] Wind tunnel test is an important aerodynamic experimental method used to study the interaction between gas flow and aircraft models in order to understand the aerodynamic characteristics of aircraft. In power simulation wind tunnel force measurement tests such as TPS nacelles or air motor driven propellers, unlike real engines, engine simulation devices are mostly driven by high-pressure gas. In order to drive the engine simulation device, a dedicated pipeline is required to deliver high-pressure air. According to the test technical requirements, this type of wind tunnel test needs to be equipped with a corresponding internal air bridge balance to reduce the impact of high-pressure air supply and low-pressure return air on the balance caused by inaccurate measurement. The problem that must be solved in the power simulation test is that the pipeline can not only deliver high-pressure air, but also have a small and stable impact on the balance force measurement, and at the same time overcome the internal force, temperature effect, flow effect, etc. of high-pressure air. The internal air bridge balance is the most advanced technology to solve this problem at present. It is one of the key technologies of power simulation test technology and is widely used in tests such as TPS nacelle power simulation and air motor driven propeller simulation.

[0003] The internal air bridge balance can greatly eliminate the influence of high-pressure air flow on the balance accuracy and play the force measurement function of the wind tunnel balance normally. The function of the internal air bridge balance is to transmit high-pressure air without affecting the force measurement accuracy of the balance. Specifically, the aerodynamic load of the model is transmitted to the support system through the balance and the air bridge pipeline at the same time. The air bridge pipeline must be able to transport high-pressure air and must also be properly decoupled so that the entire air supply pipeline has a "small" and "stable" influence on the force measurement of the balance.

[0004] The internal air bridge balance system consists of a six-component rod balance, a pipeline connection flange, and an air bridge pipeline. Each air bridge pipeline consists of three interference elimination units and several special-shaped metal round tubes. The three interference elimination units are placed in two perpendicular directions to ensure that each set of pipeline air bridges has six degrees of freedom interference elimination capabilities and reduce the influence of the air bridge on the force measurement of the balance. Under normal circumstances, the internal air bridge balance system is an independent system as a whole. The balance and the air bridge management are used together to carry out balance calibration and wind tunnel tests, and are generally not disassembled for use. When designing the wind tunnel test model, it is necessary to design corresponding support parts, model main load-bearing parts, and air supply pipelines and other components to adapt to the air bridge balance. The model needs to arrange an air bridge balance with two high-pressure air supplies and two low-pressure return air in the limited space of the fuselage, and it is also necessary to install and arrange a flow control unit in the model. According to the test requirements, it is necessary to bury two high-pressure gas supply pipelines and two low-pressure exhaust pipelines in the model to provide high-pressure gas and recovered low-pressure gas for the two power units respectively. However, due to the relatively large space size of the air bridge pipeline and the small internal space of some test models, it is impossible to completely wrap the independent air bridge balance system inside the model and achieve reliable connection of other parts such as the air inlet and return pipelines and flow control unit. Therefore, it is difficult to carry out the design work of the test model, which affects the implementation of wind tunnel tests.

[0005] Therefore, the present application proposes an integrated structure, design method and assembly method of an air bridge balance air inlet and return system to solve the above problems. Summary of the invention

[0006] The purpose of the present invention is to solve the problem of wind tunnel model structure design caused by the difficulty of overall arrangement of the air bridge balance air inlet and return system due to insufficient model space. A brief overview of the present invention is given below to provide a basic understanding of certain aspects of the present invention. It should be understood that this overview is not an exhaustive overview of the present invention. It is not intended to identify the key or important parts of the present invention, nor is it intended to limit the scope of the present invention.

[0007] The technical solution of the present invention:

[0008] Solution 1: An integrated structure of an air bridge balance air inlet and return system, including a flow control unit, a balance front connector, a ventilation wing, a fuselage load-bearing member, a support member, an internal strain balance and an air bridge pipeline. The internal strain balance and the air bridge pipeline are respectively installed in the fuselage load-bearing member. The air bridge pipeline includes a high-pressure air inlet pipeline and a low-pressure air return pipeline. The two high-pressure air inlet pipelines and the two low-pressure air return pipelines are all embedded in the fuselage load-bearing member in the form of a gooseneck air bridge layout. The measuring end of the internal strain balance is connected to the fuselage load-bearing member through the balance front connector. The high-pressure air inlet pipeline is connected to the air inlet of the flow control unit, the air outlet of the flow control unit is connected to the high-pressure air inlet of the ventilation wing, the low-pressure air return port of the ventilation wing is connected to the low-pressure air return pipeline, and the high-pressure air inlet pipeline, the low-pressure air return pipeline and the internal strain balance are respectively connected to the support member.

[0009] Furthermore, a plurality of noise elimination units are respectively installed on the high-pressure air intake pipeline and the low-pressure air return pipeline.

[0010] Furthermore, the measuring end of the internal strain balance is connected to a first connecting flange, the fixed end of the internal strain balance is connected to a second connecting flange, and the internal strain balance is connected to the high-pressure intake pipeline and the low-pressure return pipeline through the first connecting flange and the second connecting flange.

[0011] Furthermore, a middle fuselage cover is installed on the fuselage load-bearing member, and after the fuselage load-bearing member and the middle fuselage cover are connected, they are used to maintain the geometric shape of the model's outer surface.

[0012] Solution 2: A design method for an integrated structure of an air bridge balance air inlet and return system, which is used to design the integrated structure of an air bridge balance air inlet and return system described in Solution 1, and includes the following steps:

[0013] Step 1: Design an internal strain balance. According to the test requirements and the GJB0011A-2011 wind tunnel strain balance specification, select the balance form, design the balance dimensions and interfaces, design the balance components, and calculate and check them, and complete all the design work of the balance.

[0014] Step 2: Calculate air bridge pipe parameters

[0015] (1)

[0016] In the formula is the air density, P is the maximum design pressure of the pipeline, m is the molar mass of air, R is the universal gas constant, and T is the Kelvin temperature;

[0017] (2)

[0018] Where S is the flow area of ​​the air bridge pipeline, M is the mass flow rate of the air bridge single tube, is the air flow rate in the air bridge pipeline;

[0019] The air bridge pipe is a round pipe, so:

[0020] (3)

[0021] Where D is the inner diameter of the air bridge pipe, S is the flow area of ​​the air bridge pipe, and π is the pi;

[0022] According to the performance of the air bridge pipe material, welding requirements, pipe deadweight, and other component connection thickness and sealing requirements, the pipe wall thickness t is selected, and then the pipe wall thickness pressure resistance check is performed, requiring the actual selected wall thickness to be greater than the minimum pressure resistance wall thickness;

[0023] (4)

[0024] Where t is the minimum wall thickness for pressure resistance, D1 is the outer diameter of the pipe, is the allowable stress of pipeline material, Ej is the welding coefficient, which is 1 for seamless steel pipe, and Y is the influence coefficient;

[0025] Step 3: Design of the interference elimination unit. The interference elimination unit uses elastic rubber rings or bellows to seal the pipeline and eliminate elastic interference. The form of the interference elimination unit is selected to meet the internal space requirements of the full-powered model, so that there is a gap between the air bridge pipeline and the inner cavity of the fuselage load-bearing parts and the internal strain balance to ensure the reliability of the internal strain balance, optimize the size of the air bridge interference elimination unit and the distance between them, and reduce the influence of the air bridge system on the stiffness of the balance;

[0026] Step 4: Design of air bridge pipeline layout. The air bridge pipeline layout design adopts a gooseneck air bridge layout with two air inlets and two air returns;

[0027] Step 5: Distribute the high-pressure air intake pipeline, low-pressure air return pipeline and internal strain balance in the fuselage load-bearing parts to ensure that the rigidity of the fuselage load-bearing parts meets the test requirements, optimize the fuselage load-bearing parts, disassemble and assemble the high-pressure air intake pipeline and the low-pressure air return pipeline, form an assembly and debugging plan, and realize the design of the integrated structure of the air intake and return system.

[0028] Solution 3: A method for assembling an integrated structure of an air bridge balance air inlet and return system, which is implemented based on the integrated structure of an air bridge balance air inlet and return system described in Solution 1, and includes the following steps:

[0029] Step 1: Install temporary mounting blocks on the fuselage load-bearing parts and one side of the fixed end of the internal strain balance, hoist the fuselage load-bearing parts, place the internal strain balance vertically on the platform, and keep the fixed end of the internal strain balance facing downward;

[0030] Step 2: Lift the fuselage load-bearing member and put it on the internal strain balance, and install the high-pressure air intake pipeline and the low-pressure air return pipeline on the fuselage load-bearing member;

[0031] Step 3: Position the first connecting flange and the measuring end of the internal strain balance through pins, connect them through screws, position the second connecting flange and the fixed end of the internal strain balance through pins, connect them through screws, connect the high-pressure air intake pipeline to the first connecting flange, and connect the low-pressure air return pipeline to the second connecting flange;

[0032] Step 4: Install the front connector of the balance to connect the measuring end of the internal strain balance and the high-pressure air intake pipe and the low-pressure air return pipe into one;

[0033] Step 5: Use a crane to hoist the fuselage load-bearing parts, the internal strain balance and the air bridge pipeline as a whole, remove the temporary installation block, and connect and fix the first connecting flange and the second connecting flange on the internal strain balance to the high-pressure air intake pipeline and the low-pressure air return pipeline;

[0034] Step 6: Adjust the angle between the fuselage load-bearing parts and the internal strain balance, place the balance angle measurement component on the upper measuring surface of the internal strain balance measurement end, loosen the connecting screws between the front connecting part of the balance and the internal strain balance when measuring the angle, and tighten the screws after the angle adjustment is completed;

[0035] Step 7: Install the support at the fixed end of the internal strain balance, connect and seal the high-pressure air intake pipeline, the low-pressure air return pipeline and the internal strain balance with the support, and perform the wiring of the cable line;

[0036] Step 8: Install the ventilation wing on top of the fuselage load-bearing parts and tighten it;

[0037] Step 9: Install the flow control unit and its associated pipelines at the measuring end of the internal strain balance to ensure the connection and sealing of the pipelines;

[0038] Step 10: Install the middle fuselage cover on the outside of the fuselage load-bearing parts to complete the assembly of the integrated structure of the air bridge balance air inlet and return system.

[0039] The present invention has the following beneficial effects:

[0040] 1. The integrated structure of the air bridge balance air inlet and return air system of the present invention is simple and practical, and the structural rigidity meets the practical requirements of wind tunnel tests. It can significantly improve the technical capabilities of wind tunnel tests for power simulations such as TPS nacelles and air motor-driven propellers, and plays an important role in improving the applicability and reliability of air bridge air inlet and return air systems, and has a very broad application prospect.

[0041] 2. The integrated structural design method of the air bridge balance air inlet and return system of the present invention can cleverly disassemble the four-way air inlet and return air bridge balance and integrate it into the fuselage load-bearing parts. Through the reasonable design and layout of the ventilation wing, flow control unit and other connecting mechanisms, the wing and the ventilation pipeline are integrated at the same time. The number of ventilation pipelines and space restrictions are greatly reduced. Therefore, the design method can solve the wind tunnel model structural design problem caused by the lack of internal space in the fuselage and the difficulty in overall layout of the air bridge balance air inlet and return system. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is the front view of the integrated structure of the air bridge balance air inlet and return system;

[0043] Figure 2 It is an axial view of the integrated structure of the air bridge balance inlet and return air system;

[0044] Figure 3 It is a schematic diagram of the load-bearing parts of the fuselage;

[0045] Figure 4 It is a schematic diagram of the matching relationship between the internal strain balance, the first connecting flange and the second connecting flange;

[0046] Figure 5 It is a schematic diagram of the coordination relationship between the fuselage load-bearing parts and the low-pressure return air pipeline;

[0047] Figure 6 It is a schematic diagram of the matching relationship between the fuselage load-bearing parts and the front connecting parts of the balance;

[0048] Figure 7 It is the installation flow chart of the integrated mechanism of the air bridge balance air inlet and return system.

[0049] In the figure: 1-flow control unit, 2-front connecting piece of balance, 3-high-pressure air intake pipe, 4-ventilation wing, 5-fuselage load-bearing member, 6-support member, 7-first connecting flange, 8-low-pressure return air pipe, 9-internal strain balance, 10-middle fuselage cover, 11-second connecting flange, 12-disturbance elimination unit. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described below by the specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0051] The connection mentioned in the present invention is divided into fixed connection and detachable connection. The fixed connection (i.e., non-detachable connection) includes but is not limited to conventional fixed connection methods such as folding connection, rivet connection, bonding connection and welding connection. The detachable connection includes but is not limited to conventional detachable methods such as threaded connection, snap connection, pin connection and hinge connection. When the specific connection method is not clearly defined, it is assumed that at least one connection method can always be found in the existing connection methods to achieve the function. Those skilled in the art can choose according to their needs. For example: welding connection is selected for fixed connection, and hinge connection is selected for detachable connection.

[0052] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0053] Embodiment 1, combination Figure 1-Figure 6 The present embodiment is described. The integrated structure of the air bridge balance air intake and return system of the present embodiment comprises a flow control unit 1, a balance front connector 2, a ventilation wing 4, a fuselage load-bearing member 5, a support member 6, an internal strain balance 9 and an air bridge pipeline. The internal strain balance 9 and the air bridge pipeline are respectively installed in the fuselage load-bearing member 5. The air bridge pipeline comprises a high-pressure air intake pipeline 3 and a low-pressure air return pipeline 8. Both the two high-pressure air intake pipelines 3 and the two low-pressure air return pipelines 8 are embedded in the fuselage load-bearing member 5 in the form of a gooseneck air bridge layout. The measuring end of the internal strain balance 9 is connected to the fuselage load-bearing member 5 through the balance front connector 2. The high-pressure air intake pipeline 3 is connected to the air inlet of the flow control unit 1. The air outlet of the flow control unit 1 is connected to the high-pressure air inlet of the ventilation wing 4. The low-pressure air return port of the ventilation wing 4 is connected to the low-pressure air return pipeline 8. The high-pressure air intake pipeline 3, the low-pressure air return pipeline 8 and the internal strain balance 9 are respectively connected to the support member 6.

[0054] After the internal strain balance 9 is placed in the fuselage load-bearing member 5, the measuring end of the internal strain balance 9 is connected to the first connecting flange 7, the fixed end of the internal strain balance is connected to the second connecting flange 11, the internal strain balance 9 is connected to the low-pressure return air pipeline 8 and the high-pressure air intake pipeline 3 through the first connecting flange 7 and the second connecting flange 11, the front connecting member 2 of the balance is connected to the measuring end of the internal strain balance 9 and the fuselage load-bearing member 5 at the same time, the fixed end of the internal strain balance 9 and the high-pressure air intake pipeline 3, the low-pressure air return pipeline 8 are connected to the support member 6 at the same time, the high-pressure air intake pipeline 3 is connected to the air inlet of the flow control unit 1, the air outlet of the flow control unit 1 is connected to the high-pressure air inlet of the ventilation wing 4, the low-pressure air return port of the ventilation wing 4 is connected to the low-pressure air return pipeline 8, and after the assembly is completed, the middle fuselage cover 10 is installed on both sides of the fuselage load-bearing member 5 for shape preservation. Sufficient safety clearance is reserved between each non-contact component.

[0055] Multiple interference elimination units 12 are installed on each pipeline of the high-pressure air intake pipeline 3 and the low-pressure air return pipeline 8. In this embodiment, three interference elimination units 12 are arranged on each pipeline. Each interference elimination unit 12 is equivalent to a cross hinge. The six-degree-of-freedom interference elimination function of the air bridge pipeline is realized by the interference elimination units 12 distributed at different positions.

[0056] The fuselage load-bearing member 5 is equipped with a middle fuselage cover plate 10, which is circular in shape after being connected to the fuselage load-bearing member 5, to ensure the geometric similarity of the fuselage model. The internal strain balance 9, the first connecting flange 7, the high-pressure air intake pipeline 3 and the low-pressure air return pipeline 8 are wrapped in the fuselage model formed by the fuselage load-bearing member 5 and the middle fuselage cover plate 10. The fuselage load-bearing member 5 and the internal strain balance 9 are connected into one body by the front balance connecting member 2 to form an integrated air bridge balance system for air intake and return. Combined with the support member 6 at the rear end of the fuselage, the flow control unit 1 at the front end of the internal strain balance 9 and the upper ventilation wing 4, a complete integrated structure of the air bridge balance air intake and return system is formed.

[0057] First, place the internal strain balance 9 vertically into the fuselage load-bearing member 5, place the two high-pressure air intake pipes 3 and the two low-pressure air return pipes 8 into the predetermined positions, and then install the first connecting flange 7 and the second connecting flange 11, and then install the front connecting member 2 of the balance to connect the fuselage load-bearing member 5, the internal strain balance 9, the high-pressure air intake pipes 3 and the low-pressure air return pipes 8 at the measuring end of the internal strain balance 9 as a whole. After completing this step, the air bridge balance can be used as a whole to carry out sealing tests and balance calibration.

[0058] After the balance calibration work is completed, the support part 6 is installed at the rear end of the internal strain balance 9, the ventilation wing 4 is installed above the fuselage load-bearing part 5, and the flow control unit 1 is installed at the front end of the balance front connecting part 2. The integrated assembly of the air bridge balance air inlet and return system is completed, and the final sealing test and wind tunnel test are carried out.

[0059] During the test, the high-pressure gas first enters the two-way high-pressure air inlet pipe 3 of the air bridge balance through the support 6, and after being adjusted by the flow control device, enters the power simulation device through the high-pressure pipe inside the ventilation wing 4. After work, the low-pressure gas is discharged, and then flows through the two-way low-pressure return pipe 8 of the air bridge balance through the low-pressure pipe inside the model, and finally is discharged out of the wind tunnel through the support 6 again.

[0060] Embodiment 2, combined Figure 1-Figure 6 This embodiment is described. This embodiment is a design method for an integrated structure of an air bridge balance air inlet and return system, which specifically includes the following steps:

[0061] Step 1: Design an internal strain balance 9. According to the test requirements and the GJB0011A-2011 wind tunnel strain balance specification, select the balance form, design the balance dimensions and interfaces, design and calculate and check the balance components, and complete the entire design of the balance.

[0062] Step 2: Calculate air bridge pipe parameters

[0063] (1)

[0064] In the formula is the air density, P is the maximum design pressure of the pipeline, m is the molar mass of air, R is the universal gas constant, and T is the Kelvin temperature;

[0065] (2)

[0066] Where S is the flow area of ​​the air bridge pipeline, M is the mass flow rate of the air bridge single tube, is the air flow rate in the air bridge pipeline;

[0067] The air bridge pipe is a round pipe, so:

[0068] (3)

[0069] Where D is the inner diameter of the air bridge pipe, S is the flow area of ​​the air bridge pipe, and π is the pi;

[0070] According to the performance of the air bridge pipe material, welding requirements, pipe deadweight, and other component connection thickness and sealing requirements, the pipe wall thickness t is selected, and then the pipe wall thickness pressure resistance check is performed, requiring the actual selected wall thickness to be greater than the minimum pressure resistance wall thickness;

[0071] (4)

[0072] Where t is the minimum wall thickness for pressure resistance, D1 is the outer diameter of the pipe, is the allowable stress of pipeline material, Ej is the welding coefficient, which is 1 for seamless steel pipe, and Y is the influence coefficient;

[0073] Step 3: Design of the interference elimination unit. The interference elimination unit adopts elastic rubber ring or bellows to seal the pipeline and eliminate elastic interference. The form of the interference elimination unit is selected to meet the internal space requirements of the full-powered model, so that a gap is left between the air bridge pipeline and the inner cavity of the fuselage load-bearing member 5 and the internal strain balance 9, ensuring the reliability of the internal strain balance 9, optimizing the size of the air bridge interference elimination unit and the distance between them, and reducing the influence of the air bridge system on the stiffness of the balance;

[0074] Step 4: Design of air bridge pipeline layout. The air bridge is mainly divided into gooseneck type, L type and direct connection type. After combination, they can achieve six degrees of freedom decoupling. From the perspective of interference elimination performance, the direct connection type has relatively weak axial force interference elimination ability, but occupies more space than the direct connection type. The L type is generally more suitable for external balances. It needs to be selected after comprehensive consideration of interference elimination ability and space layout. Therefore, the gooseneck air bridge layout with two air inlets and two air returns is finally selected;

[0075] Step 5: Distribute the high-pressure air intake pipeline 3, the low-pressure air return pipeline 8 and the internal strain balance 9 in the fuselage load-bearing parts 5 to ensure that the rigidity of the fuselage load-bearing parts 5 meets the test requirements, optimize the fuselage load-bearing parts 5, disassemble and assemble the high-pressure air intake pipeline 3 and the low-pressure air return pipeline 8, form an assembly and debugging plan, and realize the detailed design of the integrated structure of the air intake and return system.

[0076] Embodiment 3, combined Figure 1-Figure 6 This embodiment is described. This embodiment is a design method for an integrated structure of an air bridge balance air inlet and return system, which specifically includes the following steps:

[0077] Step 1: Install temporary mounting blocks on one side of the fuselage load-bearing member 5 and the fixed end of the internal strain balance 9, hoist the fuselage load-bearing member 5, and place the internal strain balance 9 vertically on the platform, keeping the fixed end of the internal strain balance 9 facing downward;

[0078] Step 2: Lift the fuselage load-bearing member 5 and put it on the internal strain balance 9, and install the high-pressure air intake pipeline 3 and the low-pressure air return pipeline 8 on the fuselage load-bearing member 5;

[0079] Step 3: Position the first connecting flange 7 and the measuring end of the internal strain balance 9 by pins, connect them by screws, position the second connecting flange 11 and the fixed end of the internal strain balance 9 by pins, connect them by screws, connect the high-pressure air intake line 3 to the first connecting flange 7, and connect the low-pressure air return line 8 to the second connecting flange 11;

[0080] Step 4: Install the front connecting piece 2 of the balance to connect the measuring end of the internal strain balance 9 and the high-pressure air intake pipe 3 and the low-pressure air return pipe 8 into one;

[0081] Step 5: Use a crane to hoist the fuselage load-bearing member 5, the internal strain balance 9 and the air bridge pipeline as a whole, remove the temporary installation block, and connect and fix the first connecting flange 7 and the second connecting flange 11 on the internal strain balance 9 to the high-pressure air intake pipeline 3 and the low-pressure air return pipeline 8;

[0082] Step 6: Adjust the angle between the fuselage load-bearing member 5 and the internal strain balance 9, place the balance angle measuring component on the upper measuring surface of the measuring end of the internal strain balance 9, loosen the connecting screws between the front connecting member 2 of the balance and the internal strain balance 9 when measuring the angle, and tighten the screws after the angle adjustment is completed;

[0083] Step 7: Install the support 6 at the fixed end of the internal strain balance 9, connect and seal the high-pressure air intake pipeline 3, the low-pressure air return pipeline 8 and the internal strain balance 9 with the support 6, and perform the wiring of the cable line;

[0084] Step 8: Install the ventilation wing 4 on top of the fuselage load-bearing member 5 and tighten it;

[0085] Step 9: Install the flow control unit 1 and its associated pipelines at the measuring end of the internal strain balance 9 to ensure the connection and sealing of the pipelines;

[0086] Step 10: Install the fuselage cover 10 on the outside of the fuselage load-bearing member 5 to complete the assembly of the integrated structure of the air bridge balance air inlet and return system.

[0087] This embodiment is only an exemplary description of the present invention and does not limit its protection scope. Those skilled in the art may also make partial changes thereto. As long as they do not exceed the spirit of the present invention, they are within the protection scope of the present invention.

Claims

1. The integrated structure of the air bridge balance air inlet and return system is characterized by: The invention comprises a flow control unit (1), a balance front connection part (2), a ventilation wing (4), a fuselage load-bearing part (5), a support part (6), an internal strain balance (9) and an air bridge pipeline. The internal strain balance (9) and the air bridge pipeline are respectively installed in the fuselage load-bearing part (5). The air bridge pipeline comprises a high-pressure air intake pipeline (3) and a low-pressure air return pipeline (8). The two high-pressure air intake pipelines (3) and the two low-pressure air return pipelines (8) are all embedded in the fuselage load-bearing part (5) in the form of a gooseneck air bridge layout. 5), the measuring end of the internal strain balance (9) is connected to the fuselage load-bearing member (5) through the balance front connecting member (2), the high-pressure air intake pipeline (3) is connected to the air intake port of the flow control unit (1), the air outlet of the flow control unit (1) is connected to the high-pressure air intake port of the ventilation wing (4), the low-pressure air return port of the ventilation wing (4) is connected to the low-pressure air return pipeline (8), and the high-pressure air intake pipeline (3), the low-pressure air return pipeline (8) and the internal strain balance (9) are respectively connected to the support member (6).

2. The integrated structure of the air bridge balance air inlet and return system according to claim 1 is characterized by: A plurality of noise elimination units (12) are respectively installed on the high-pressure air intake pipeline (3) and the low-pressure air return pipeline (8).

3. The integrated structure of the air bridge balance air inlet and return system according to claim 1 is characterized in that: The measuring end of the internal strain balance (9) is connected to a first connecting flange (7), the fixed end of the internal strain balance (9) is connected to a second connecting flange (11), and the internal strain balance (9) is connected to the high-pressure air intake pipeline (3) and the low-pressure air return pipeline (8) via the first connecting flange (7) and the second connecting flange (11).

4. The integrated structure of the air bridge balance air inlet and return system according to claim 2 is characterized in that: A middle fuselage cover plate (10) is mounted on the fuselage load-bearing member (5), and the fuselage load-bearing member (5) and the middle fuselage cover plate (10) are connected to each other to maintain the geometric shape of the model's outer profile.

5. A method for designing an integrated structure of an air bridge balance air inlet and return system, the method being used to design an integrated structure of an air bridge balance air inlet and return system as claimed in claim 3, characterized in that: The following steps are involved: Step 1: Design an internal strain balance (9). According to the test requirements and the GJB0011A-2011 wind tunnel strain balance specification, select the balance type, design the balance dimensions and interfaces, design the balance components, and calculate and verify them, and complete the entire design of the balance. Step 2: Calculate air bridge pipe parameters （1） In the formula is the air density, P is the maximum design pressure of the pipeline, m is the molar mass of air, R is the universal gas constant, and T is the Kelvin temperature; （2） Where S is the flow area of ​​the air bridge pipeline, M is the mass flow rate of the air bridge single tube, is the air flow rate in the air bridge pipeline; The air bridge pipe is a round pipe, so: （3） Where D is the inner diameter of the air bridge pipe, S is the flow area of ​​the air bridge pipe, and π is the pi; According to the performance of the air bridge pipe material, welding requirements, pipe deadweight, and other component connection thickness and sealing requirements, the pipe wall thickness t is selected, and then the pipe wall thickness pressure resistance check is performed, requiring the actual selected wall thickness to be greater than the minimum pressure resistance wall thickness; （4） Where t is the minimum wall thickness for pressure resistance, D1 is the outer diameter of the pipe, is the allowable stress of pipeline material, Ej is the welding coefficient, which is 1 for seamless steel pipe, and Y is the influence coefficient; Step 3: Design of the interference elimination unit. The interference elimination unit uses an elastic rubber ring or a bellows to seal the pipeline and eliminate elastic interference. The form of the interference elimination unit is selected to meet the internal space requirements of the full-power mold, so that a gap is left between the air bridge pipeline and the inner cavity of the fuselage load-bearing member (5) and the internal strain balance (9), ensuring the reliability of the internal strain balance (9), optimizing the size of the air bridge interference elimination unit and the distance between them, and reducing the influence of the air bridge system on the stiffness of the balance; Step 4: Design of air bridge pipeline layout. The air bridge pipeline layout design adopts a gooseneck air bridge layout with two air inlets and two air returns; Step 5: The high-pressure air intake pipeline (3), the low-pressure air return pipeline (8) and the internal strain balance (9) are dispersedly arranged in the fuselage load-bearing member (5) to ensure that the rigidity of the fuselage load-bearing member (5) meets the test requirements, the fuselage load-bearing member (5) is optimized, the high-pressure air intake pipeline (3) and the low-pressure air return pipeline (8) are disassembled and assembled, an assembly and debugging plan is formed, and the design of the integrated structure of the air intake and return system is realized.

6. A method for assembling an integrated structure of an air bridge balance air inlet and return system, the method being realized by the integrated structure of an air bridge balance air inlet and return system as claimed in claim 3, characterized in that: The following steps are involved: Step 1: Install a temporary installation block between the fuselage load-bearing member (5) and one side of the fixed end of the internal strain balance (9), hoist the fuselage load-bearing member (5), and place the internal strain balance (9) vertically on the platform, keeping the fixed end of the internal strain balance (9) facing downward; Step 2: Lift the fuselage load-bearing member (5) and place it on the internal strain balance (9), and install the high-pressure air intake pipeline (3) and the low-pressure air return pipeline (8) on the fuselage load-bearing member (5); Step 3: Position the first connecting flange (7) and the measuring end of the internal strain balance (9) by means of pins, connect them by means of screws, position the second connecting flange (11) and the fixed end of the internal strain balance (9) by means of pins, connect them by means of screws, connect the high-pressure air intake pipeline (3) to the first connecting flange (7), and connect the low-pressure air return pipeline (8) to the second connecting flange (11); Step 4: Install the front connecting piece (2) of the balance to connect the measuring end of the internal strain balance (9) and the high-pressure air intake pipe (3) and the low-pressure air return pipe (8) into one; Step 5: hoist the fuselage load-bearing member (5), the internal strain balance (9) and the air bridge pipeline as a whole by a crane, remove the temporary installation block, and connect and fix the first connecting flange (7) and the second connecting flange (11) on the internal strain balance (9) to the high-pressure air intake pipeline (3) and the low-pressure air return pipeline (8); Step 6: Adjust the angle between the fuselage load-bearing member (5) and the internal strain balance (9), place the balance angle measuring component on the upper measuring surface of the measuring end of the internal strain balance (9), loosen the connecting screws between the front connecting member (2) of the balance and the internal strain balance (9) when measuring the angle, and tighten the screws after the angle adjustment is completed; Step 7: Install the support member (6) at the fixed end of the internal strain balance (9), connect and seal the high-pressure air intake pipeline (3) and the low-pressure air return pipeline (8) as well as the internal strain balance (9) with the support member (6), and then perform the wiring of the cable line; Step 8: Install the ventilation wing (4) on top of the fuselage load-bearing member (5) and fasten it; Step 9: Install the flow control unit (1) and its associated pipelines at the measuring end of the internal strain balance (9), ensuring the connection and sealing of the pipelines; Step 10: Install the middle fuselage cover plate (10) on the outside of the fuselage load-bearing member (5) to complete the assembly of the integrated structure of the air bridge balance air inlet and return system.

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