Airbag deicing system icing wind tunnel test device and method with pressure measurement function

Abstract

The present application belongs to the technical field of aircraft icing wind tunnel test, and relates to an icing wind tunnel test device and method of an airbag deicing system with pressure measurement function. The device comprises a pressure measurement leading edge assembly (1), a deicing leading edge assembly (2) and a wing box assembly (3). The pressure measurement leading edge assembly (1) and the deicing leading edge assembly (2) are interchangeable leading edge modules, and the wing box assembly (3) comprises a wing box and a trailing edge part. The pressure measurement leading edge assembly (1) and the deicing leading edge assembly (2) have the same shape, and the pressure measurement leading edge assembly (1) or the deicing leading edge assembly (2) and the wing box assembly (3) jointly form a complete wing section and are connected into one body by fasteners for pressure measurement test or deicing test. By comparison and matching with a target pressure distribution, an accurate test attack angle is determined, so that the test state is closer to the real flight state, and the reliability of the deicing test result is improved.

Description

Technical Field

[0001] This invention belongs to the field of aircraft icing wind tunnel testing technology, and relates to an icing wind tunnel testing device and method for an airbag de-icing system with pressure measurement function. Background Technology

[0002] When an aircraft passes through an icing cloud formed by supercooled water droplets, varying degrees of icing will occur on the windward surfaces of the wings, tail, air intakes, protrusions, and other components. Icing can deteriorate the aircraft's aerodynamic characteristics, reduce performance, and even cause critical systems to fail, seriously threatening flight safety.

[0003] To ensure safe flight in icing environments, critical components such as the leading edge of the wing typically require icing protection, necessitating the design of corresponding anti-icing or de-icing systems to eliminate or reduce the impact of icing. Airbag de-icing is a mature technology. Its basic principle involves attaching rubber airbags to the leading edge of the wing. Each airbag contains multiple chambers. During normal flight, the airbag maintains its aerodynamic shape. When entering an icing zone, the chambers inflate, causing the airbag to expand and break up the surface ice layer, which is then blown away by aerodynamic forces. Due to its low energy consumption, light weight, and simple structure, airbag de-icing systems are widely used in low-speed aircraft.

[0004] Airbag de-icing is a type of mechanical de-icing. To evaluate the protective effectiveness of a de-icing system, airworthiness regulations typically require verification through ice wind tunnel testing to obtain the critical ice type under operating conditions, providing input for further flight performance and handling characteristics evaluation. However, current ice wind tunnel testing of de-icing systems has certain limitations:

[0005] Firstly, due to the lack of similar theoretical support, the wind tunnel test of the airbag de-icing system can only use 1:1 test pieces. Due to the size limitation of the wind tunnel, only a local wing section can generally be used as the test piece, resulting in a difference between the test configuration and the actual aircraft configuration.

[0006] Secondly, when the obstruction of the test piece is large, it will also be affected by the wind tunnel wall, causing the test state to deviate further from the actual flight state.

[0007] Therefore, from an aerodynamic perspective, wind tunnel tests of airbag de-icing systems cannot directly simulate real flight conditions. This discrepancy increases test errors and affects the evaluation and verification of de-icing effectiveness. The key to solving this problem lies in obtaining the pressure distribution on the test specimen surface during the test. By adjusting the test angle of attack, the test pressure distribution is gradually made to approximate the target pressure distribution during aircraft flight until they match. At this point, the flow is considered similar, and the test can better reflect the real situation. However, the surface of the airbag de-icing system cannot have openings, making it impossible to directly use mature pressure measurement hole schemes.

[0008] In summary, there is an urgent need to design a new wind tunnel testing device for airbag de-icing systems and determine suitable testing methods to solve the problem of simultaneously conducting pressure measurement and de-icing tests, obtain accurate test angles of attack, and improve the reliability of wind tunnel tests of airbag de-icing systems. Summary of the Invention

[0009] Purpose of the invention

[0010] A wind tunnel testing device and method for an airbag de-icing system with pressure measurement capability is proposed. During the pressure measurement test, the pressure distribution on the surface of the testing device can be measured in real time. By adjusting the test angle of attack, the test pressure distribution is matched with the target pressure distribution under the aircraft's flight conditions, thereby ensuring good similarity between the flow under test and real conditions. Based on the test angle of attack determined by the pressure measurement test, conventional wind tunnel tests of the airbag de-icing system are further carried out.

[0011] Technical solution

[0012] An ice wind tunnel test device for an airbag de-icing system with pressure measurement function includes: a pressure measurement leading edge assembly (1), a de-icing leading edge assembly (2), and a wing box assembly (3). The pressure measurement leading edge assembly (1) and the de-icing leading edge assembly (2) are interchangeable leading edge modules, and the wing box assembly (3) includes a wing box and a trailing edge portion. The pressure measurement leading edge assembly (1) and the de-icing leading edge assembly (2) have the same shape. The pressure measurement leading edge assembly (1) or the de-icing leading edge assembly (2) and the wing box assembly (3) together form a complete wing section and are connected as one unit by fasteners for pressure measurement tests or de-icing tests.

[0013] The pressure testing leading edge assembly (1) includes: a skin, end ribs (4), intermediate ribs (5), stringers (6), connecting strips (7), and a thickened base plate (8) for the pressure testing tube. The end ribs (4) and intermediate ribs (5) are provided with grooves through which the stringers (6) pass. The end ribs (4), intermediate ribs (5), and stringers (6) together form a structural frame. The connecting strips (7) connect the end ribs (4) and intermediate ribs (5) and are located at the rear end of the end ribs (4) and intermediate ribs (5). The connecting strips (7) are connected to the wing box assembly (3) by fasteners. The skin covers the outside of the structural frame and has pressure testing holes. The thickened base plate (8) for the pressure testing tube is set on the inside of the skin with the pressure testing holes to support the skin and make the connection between the pressure testing tube and the skin more secure. The pressure testing tube connects to the pressure testing holes, passes through the intermediate ribs (5) and end ribs (4), and is led out of the test section to the pressure testing scanning valve instrument.

[0014] The de-icing leading edge assembly (2) includes: a skin, end ribs (4), intermediate ribs (5), stringers (6), connecting strips (7), and de-icing airbags (9). The end ribs (4) and intermediate ribs (5) have grooves through which the stringers (6) pass, and the end ribs (4), intermediate ribs (5), and stringers (6) together form a structural frame. The connecting strips (7) connect the end ribs (4) and intermediate ribs (5) and are located at the rear ends of the end ribs (4) and intermediate ribs (5). The connecting strips (7) are connected to the wing box assembly (3) via fasteners. The skin covers the outside of the structural frame, and the de-icing airbags (9) cover the outer surface of the skin. De-icing pipes connect to the de-icing airbags (9), pass through the intermediate ribs (5) and end ribs (4), and exit from the test section, connecting to the corresponding de-icing controller and air source system. Mechanical de-icing is achieved through repeated inflation and expansion.

[0015] The wing box assembly (3) includes: a skin, end ribs (4), intermediate ribs (5), stringers (6), a front beam (10), and a rear beam (11). The end ribs (4) and intermediate ribs (5) have grooves through which the stringers (6) pass. The front beam (10) and rear beam (11) are the main load-bearing structures. The end ribs (4), intermediate ribs (5), stringers (6), front beam (10), and rear beam (11) together form a structural frame. The skin covers the outside of the structural frame. Fasteners are installed on the flanges of the front beam (10) for connection to the pressure-sensing leading edge assembly (1) or the de-icing leading edge assembly (2).

[0016] Furthermore, the pressure measurement leading edge assembly (1) can be provided with one or more rows of pressure measurement profiles.

[0017] Furthermore, the pressure measurement profile should preferably be set near the middle of the spanwise direction of the test device to reduce the influence of the wind tunnel wall and improve measurement accuracy.

[0018] Furthermore, the fasteners connecting the pressure measuring leading edge assembly (1) or the de-icing leading edge assembly (2) to the wing box assembly (3) are screws and nuts or bolts and nuts.

[0019] Furthermore, the number of the thickened base plate (8) for the pressure measuring tube on the inner surface of the skin depends on the number of pressure measuring profiles.

[0020] Furthermore, the position of the thickened base plate (8) of the pressure measuring tube on the inner surface of the skin is determined according to the position of the pressure measuring profile.

[0021] Furthermore, the test conditions with the greatest load should be considered, and the strength of the airbag de-icing system ice wind tunnel test device should be checked to ensure the safety of the connection between components.

[0022] Furthermore, both the end ribs (4) and the intermediate ribs (5) are provided with through holes for weight reduction and pipeline passage.

[0023] Furthermore, the width of the de-icing airbag (9) is consistent with the width of the airbag on the real machine to simulate the real de-icing efficiency.

[0024] A wind tunnel testing method for an airbag de-icing system with pressure measurement function includes the following steps:

[0025] S1: Based on the test conditions, the target pressure distribution of the profile where the ice wind tunnel test device is located is extracted through full-machine CFD analysis;

[0026] S2: Install the wing box assembly (3) into the ice tunnel test section;

[0027] S3: Connect the pressure measuring leading edge assembly (1) and the wing box assembly (3) with detachable fasteners;

[0028] S4: Conduct a pressure test to obtain the real-time test pressure distribution and compare it with the target pressure distribution in step S1. Only the pressure distribution in front of the front beam needs to be considered.

[0029] S5: Repeatedly adjust the test angle of attack until the test pressure distribution matches the target pressure distribution in step S1, then determine the angle of attack for the current test state;

[0030] Repeat steps S4 to S5 to match the pressure distribution of all test conditions, determine the test angle of attack for each condition, and complete the pressure test.

[0031] Furthermore, in embodiments of this method, a de-icing test is also included in steps S6 to S8:

[0032] S6: Disassemble the pressure measurement leading edge assembly (1);

[0033] S7: Connect the de-icing leading edge assembly (2) and the wing box assembly (3) with detachable fasteners;

[0034] S8: Conduct the airbag de-icing test according to the test angle determined in step S5 of the pressure test. The subsequent steps are the same as those of the conventional ice wind tunnel test.

[0035] The beneficial effects of this application are as follows:

[0036] The present invention provides an ice wind tunnel testing device and method for an airbag de-icing system with pressure measurement function, which solves the contradiction that traditional de-icing testing devices cannot be compatible with pressure measurement via pressure measuring holes, and enables both pressure measurement and de-icing tests to be performed using the same testing device. Its advantages and beneficial effects are as follows:

[0037] 1. This invention can measure the pressure distribution of the test device in real time during wind tunnel testing. By comparing and matching with the target pressure distribution, the accurate test angle of attack can be determined, thereby making the test state closer to the real flight state and improving the reliability of the de-icing test results.

[0038] 2. This invention reduces the manufacturing cost of the test device and shortens the test project cycle by using a modular, replaceable leading edge component design and sharing the wing box component.

[0039] 3. The test method of the present invention is simple and clear, and the steps of the pressure test and de-icing test are clear and easy to implement;

[0040] 4. The experimental apparatus and method of this invention can be extended to the field of ice wind tunnel testing for any type of anti-icing and de-icing system, such as hot gas, electric heating, or electric pulse. Attached Figure Description

[0041] Figure 1 This is a three-dimensional schematic diagram of an ice wind tunnel test device for an airbag de-icing system with pressure measurement function, provided in an embodiment of the present invention.

[0042] Figure 2 for Figure 1 A three-dimensional structural schematic diagram of the pressure-sensing leading edge assembly in the illustrated embodiment.

[0043] Figure 3 for Figure 1 A three-dimensional structural schematic diagram of the de-icing leading edge assembly in the illustrated embodiment.

[0044] Figure 4 for Figure 1 A three-dimensional structural diagram of the wing box assembly in the illustrated embodiment.

[0045] Figure 5 A flowchart of an ice wind tunnel test method for an airbag de-icing system with pressure measurement function, provided in an embodiment of the present invention.

[0046] In the figure, 1-Pressure measuring leading edge assembly, 2-De-icing leading edge assembly, 3-Wing box assembly; 4-End rib, 5-Intermediate rib, 6-Stringer, 7-Connecting strip plate, 8-Pressure measuring tube thickened bottom plate; 9-De-icing airbag; 10-Front beam, 11-Rear beam. Detailed Implementation

[0047] The present invention will be further described below with reference to embodiments. The following description represents only a portion of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0048] like Figure 1 As shown, this embodiment of the invention provides an ice wind tunnel test device for an airbag de-icing system with pressure measurement function, comprising: a pressure measurement leading edge assembly (1), a de-icing leading edge assembly (2), and a wing box assembly (3). By replacing the leading edge assembly, the test device is equipped with both pressure measurement and de-icing functions to simultaneously meet the requirements of pressure measurement and de-icing tests.

[0049] like Figure 2 As shown, the pressure measuring leading edge assembly (1) provided in this embodiment of the invention includes: skin, end rib (4), middle rib (5), stringer (6), connecting strip plate (7), and pressure measuring tube thickened bottom plate (8). Figure 2 The skin is hidden in the middle to facilitate the display of the internal structural components. The pressure measuring hole is on the skin of the thickened base plate (8) of the pressure measuring tube. The pressure measuring tube is connected to the pressure measuring hole, passes through the middle rib (5) and the end rib (4) and leads out of the test section, and is connected to the corresponding pressure measuring scanning valve instrument.

[0050] like Figure 3 As shown, the de-icing leading edge assembly (2) provided in this embodiment of the invention includes: skin, end ribs (4), intermediate ribs (5), stringers (6), connecting strips (7), and de-icing airbags (9). Figure 3 The skin is concealed to facilitate the display of internal structural components. The de-icing pipe connects to the airbag, passes through the middle rib (5) and the end rib (4), and leads out of the test section to the corresponding de-icing controller and air source system.

[0051] like Figure 4 As shown, the wing box assembly (3) provided in this embodiment of the invention includes: skin, end ribs (4), middle ribs (5), stringers (6), front beam (10) and rear beam (11). Figure 4 The skin is hidden to make it easier to see the internal structural components.

[0052] The pressure measurement leading edge assembly (1) can be provided with one or more rows of pressure measurement profiles. In this embodiment, a row of pressure measurement profiles is provided at the middle position of the spanwise direction of the pressure measurement leading edge assembly (1).

[0053] The pressure-sensing leading edge assembly (1) can be detachably connected to the wing box assembly (3) in various ways, such as using screws, bolts, bolts, and nuts, but is not limited thereto. In this embodiment, screws and a support plate nut are used for connection.

[0054] The de-icing leading edge assembly (2) can be detachably connected to the wing box assembly (3) in various ways, such as using screws, bolts, bolts, and nuts, but is not limited thereto. In this embodiment, screws and a bracket nut are used for connection.

[0055] In this embodiment, considering the test condition with the maximum load, the strength of the detachable connection is checked to ensure the safety of the connection between components.

[0056] like Figure 5 As shown, this embodiment of the invention provides a wind tunnel testing method for an airbag de-icing system with pressure measurement function, including two aspects: pressure measurement test and de-icing test, specifically including the following steps:

[0057] First, conduct a pressure test:

[0058] S1: Based on mature and reliable CFD methods, the aerodynamic characteristics of the entire machine are calculated and analyzed under the test conditions. The target pressure distribution of the profile where the ice wind tunnel test device is located is extracted as the benchmark data for the comparative analysis of steps S4 and S5.

[0059] S2: Install the wing box assembly (3) into the ice wind tunnel test section. Several pin holes are provided on the end ribs (4) of the wing box assembly (3). The wing box assembly (3) is connected to the upper and lower wall panels of the wind tunnel test section by pins. Note that the pins bear the aerodynamic load of the entire test device during the test. Strength verification should be carried out during the design stage of the test device.

[0060] S3: Connect the pressure testing leading edge assembly (1) and the wing box assembly (3) with detachable fasteners. During the installation process, first pass the pressure testing tube of the pressure testing leading edge assembly (1) through the end rib (4) of the wing box assembly (3), then gradually move the pressure testing leading edge assembly (1) closer to the wing box assembly (3) until the fastener holes between the two assemblies are aligned and connected with fasteners. Finally, connect the pressure testing tube to the corresponding pressure testing scanning valve.

[0061] S4: Conduct a pressure test to obtain the real-time test pressure distribution and compare it with the target pressure distribution determined in step S1. Only the pressure distribution in front of the front beam needs to be considered. The pressure distribution curve can be expressed in the form of "relative arc length ~ pressure coefficient", which is convenient for identifying the position and size of the stagnation point and suction peak.

[0062] S5: Repeatedly adjust the test angle of attack until the test pressure distribution matches the target pressure distribution determined in step S1, then determine the angle of attack for the current test state;

[0063] Repeat steps S4 to S5 to match the pressure distribution of all test conditions, determine the test angle of attack for each condition, and complete the pressure test.

[0064] Furthermore, in embodiments of this method, a de-icing test is also included in steps S6 to S8:

[0065] S6: Disassemble the pressure measuring leading edge assembly (1), first separate the pressure measuring tube from the pressure measuring scanning valve, then disassemble the fasteners between the pressure measuring leading edge assembly (1) and the wing box assembly (3), and finally move the pressure measuring leading edge assembly (1) out of the test section;

[0066] S7: Connect the de-icing leading edge assembly (2) and the wing box assembly (3) with detachable fasteners. During the installation process, first pass the de-icing pipe of the de-icing leading edge assembly (2) through the end rib (4) of the wing box assembly (3), then gradually move the de-icing leading edge assembly (2) closer to the wing box assembly (3) until the fastener holes between the two components are aligned and connected with fasteners. Finally, connect the de-icing pipe to the corresponding de-icing controller and air source system.

[0067] S8: Conduct the airbag de-icing test according to the test angle determined in step S5 of the pressure test. The subsequent steps are the same as those of the conventional ice wind tunnel test.

[0068] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the meaning consistent with their meaning in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein. The specific embodiments described above further illustrate the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An ice wind tunnel test device of a pressure measuring airbag deicing system, characterized in that it comprises a pressure measuring leading edge assembly, a deicing leading edge assembly, and a wing box assembly; the pressure measuring leading edge assembly and the deicing leading edge assembly are interchangeable leading edge modules, and the wing box assembly comprises a wing box and a trailing edge part; the pressure measuring leading edge assembly and the deicing leading edge assembly have the same shape, and the pressure measuring leading edge assembly or the deicing leading edge assembly and the wing box assembly together form a complete wing section and are connected into one body by fasteners for pressure test or deicing test; the pressure measuring leading edge assembly comprises a skin, end ribs, intermediate ribs, stringers, connecting straps, and thickened bottom plates of pressure measuring tubes; the end ribs and the intermediate ribs are provided with grooves through which the stringers pass, and the end ribs, the intermediate ribs, and the stringers together form a structural frame; the connecting straps connect the end ribs and the intermediate ribs and are located at the rear ends of the end ribs and the intermediate ribs, and the connecting straps are connected to the wing box assembly by fasteners; the skin covers the outside of the structural frame, and the skin is provided with pressure measuring holes; the thickened bottom plates of the pressure measuring tubes are arranged on the inner side of the skin provided with the pressure measuring holes to support the skin and make the connection between the pressure measuring tubes and the skin more firm; the pressure measuring tubes are connected to the pressure measuring holes, pass through the intermediate ribs and the end ribs, and then lead out test sections to be connected to a pressure scanning valve instrument; the deicing leading edge assembly comprises a skin, end ribs, intermediate ribs, stringers, connecting straps, and deicing airbags; the end ribs and the intermediate ribs are provided with grooves through which the stringers pass, and the end ribs, the intermediate ribs, and the stringers together form a structural frame; the connecting straps connect the end ribs and the intermediate ribs and are located at the rear ends of the end ribs and the intermediate ribs, and the connecting straps are connected to the wing box assembly by fasteners; the skin covers the outside of the structural frame, and the deicing airbags are wrapped on the outer surface of the skin; deicing pipelines are connected to the deicing airbags, pass through the intermediate ribs and the end ribs, and then lead out test sections to be connected to corresponding deicing controllers and air supply systems, and mechanical deicing is realized by repeated inflation and expansion; the wing box assembly comprises a skin, end ribs, intermediate ribs, stringers, front spars, and rear spars; the end ribs and the intermediate ribs are provided with grooves through which the stringers pass; the front spars and the rear spars are main load-bearing structures; the end ribs, the intermediate ribs, the stringers, the front spars, and the rear spars together form a structural frame; the skin covers the outside of the structural frame; fasteners are installed on the edge strips of the front spars for connection with the pressure measuring leading edge assembly or the deicing leading edge assembly.

2. The device according to claim 1, characterized in that one or more rows of pressure measuring profiles can be arranged in the pressure measuring leading edge assembly.

3. The device according to claim 2, characterized in that the pressure measuring profiles are preferably arranged near the middle of the spanwise direction of the test device to reduce the influence of the wind tunnel wall and improve the measurement accuracy.

4. The device according to claim 3, characterized in that the fasteners for connecting the pressure measuring leading edge assembly or the deicing leading edge assembly with the wing box assembly are screws and nuts or bolts and nuts.

5. The device according to claim 4, characterized in that the number of thickened bottom plates of pressure measuring tubes arranged on the inner surface of the skin is determined according to the number of pressure measuring profiles.

6. The device according to claim 5, characterized in that the positions of the thickened bottom plates of pressure measuring tubes arranged on the inner surface of the skin are determined according to the positions of the pressure measuring profiles.

7. The device according to claim 6, ​ ​ ​ ​ ​ ​ The ice wind tunnel test device of the airbag deicing system is strength checked in the test condition with the largest load to ensure the safety of the connection between the components.

8. The apparatus of claim 7, wherein, The end rib and the middle rib are provided with through holes for weight reduction and pipeline passing.

9. The apparatus of claim 8, wherein, The deicing airbag has the same width as the airbag of the real machine to simulate the real deicing efficiency.

10. A test method based on the apparatus of any one of claims 1-9, comprising the following steps: S1: For the test condition, the target pressure distribution of the section of the ice wind tunnel test device is extracted through full machine CFD analysis; S2: The wing box assembly is installed to the ice wind tunnel test section; S3: The pressure measuring leading edge assembly is connected to the wing box assembly by detachable fasteners; S4: The pressure test is carried out to obtain the real-time test pressure distribution, which is compared with the target pressure distribution of step S1, and only the pressure distribution in front of the front beam needs to be concerned; S5: The test attack angle is repeatedly adjusted until the test pressure distribution matches the target pressure distribution of step S1, and then the attack angle of the current test condition is determined; The steps of S4-S5 are repeated to match the pressure distribution of all test conditions and determine the test attack angle of each condition, and the pressure test is completed; S6: The pressure measuring leading edge assembly is disassembled; S7: The deicing leading edge assembly is connected to the wing box assembly by detachable fasteners; S8: The deicing airbag test is carried out according to the test attack angle determined in step S5, and the subsequent steps are the same as the conventional ice wind tunnel test.

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