A high-aspect-ratio aircraft high-speed wind tunnel load active alleviation test model

Abstract

The application discloses a high-aspect-ratio aircraft high-speed wind tunnel load active alleviation test model and belongs to the field of aircraft design. The leading edge of the test model body is single backward-swept, the cross sections of the fuselage, the wing and the wing-body transition position adopt NACA0012 airfoils, and the structure is symmetrical up and down. Three rudders are arranged at the trailing edge of the wing. The rudders arranged at the outer side of the wing are fixed rudders. The fixed rudders are connected with the wing body through replaceable variable-angle connecting pieces. Two deflection rudders arranged near the fuselage position and the middle of the wing are respectively connected with steering engines I and II arranged in the fuselage or the wing. The design structure of the application comprehensively considers the shape of the high-aspect-ratio aircraft, the design of the load active alleviation structure to be simulated, the position space design of the steering engines required for driving the rudders and the like, and provides a reliable and feasible design scheme for the high-aspect-ratio aircraft high-speed wind tunnel load active alleviation test model.

Description

Technical Field

[0001] This invention relates to the field of aircraft design. More specifically, this invention relates to an active wind tunnel load mitigation test model for high aspect ratio aircraft. Background Technology

[0002] To improve key performance indicators such as fuel economy, aircraft typically employ high aspect ratio configurations and extensive use of composite materials in the wings for weight reduction and range extension. However, this results in reduced wing structural stiffness, leading to significant aerodynamic loads during flight under airflow disturbances. This causes intense wing structural vibrations, severely impacting structural safety and passenger comfort. Active load mitigation involves actively deflecting existing control surfaces on the wing according to specific control laws, altering the airflow distribution on the wing, reducing aerodynamic loads, and rapidly calming wing vibrations.

[0003] Before applying active load mitigation technology to an aircraft, it must undergo testing and verification to ensure its safety and reliability. Wind tunnel testing is a necessary means to evaluate and assess active load mitigation technology. The wind tunnel model design for this test is usually based on the principle of dynamic similarity, and the aircraft structure is scaled down to meet the size requirements of the wind tunnel test. In high-speed wind tunnel tests, the control surfaces of traditional aeroelastic test models are at a fixed angle. However, test models used for active load mitigation must be driven by servos to achieve active deflection of the control surfaces according to a given control law during the test. On the one hand, the aerodynamic loads in high-speed wind tunnel tests are relatively larger than those in low-speed wind tunnel tests, but the size of the high-speed wind tunnel limits the size of the test model, resulting in severe limitations on the size and power of the built-in servos. Furthermore, the drive linkage between the servo and the control surface cannot extend beyond the model surface and disrupt the model's shape as it does in low-speed wind tunnels. On the other hand, the test model used for verifying the active load mitigation technology must ensure that its structural characteristics are similar to those of the original aircraft. The all-metal model obviously cannot meet the requirement of similar structural characteristics. It is necessary to use a combination of metal beams and composite materials to simulate dynamics. However, the matching design of the main components such as beams, servos, and sensors inside the model is the main challenge.

[0004] Currently, wind tunnel test models with servos are mainly divided into two categories. One category is used to measure the aerodynamic performance and control surface efficiency of aircraft (such as a servo module for a wind tunnel test model, patent application number CN202223219584.0). These test models are basically all-metal designs, focusing on the aerodynamic performance of the shape. Space is reserved inside the wing for the servo, and during the test, only the control surfaces need to be locked at a fixed angle. The dynamic performance requirements for the servo are not high, making them unsuitable for test models requiring active load mitigation. The other category is low-speed wind tunnel test models (such as a large low-speed wind tunnel elastic full-model gust load mitigation test system and method, patent application number CN202410876147.0). These models are large in size, have low aerodynamic loads, and have ample space inside for the servo. The control surfaces and servos are mostly driven by exposed linkages, so damaging the shape has little impact on the test measurements. Therefore, they are not suitable for high-speed wind tunnel models. Summary of the Invention

[0005] One object of the present invention is to solve at least the above-mentioned problems and / or defects, and to provide at least the advantages described below.

[0006] To achieve these objectives and other advantages of the present invention, a high aspect ratio aircraft high-speed wind tunnel load active mitigation test model is provided. The leading edge of the main body of the test model is single swept back, and the cross sections of the fuselage, wing and wing-body transition are all NACA0012 airfoil and have an upper and lower symmetrical structure. The trailing edge of the wing is provided with three control surfaces. Among them, the control surface located on the outer side of the wing is a fixed control surface, which is connected to the wing body through a replaceable variable angle connector. The two deflection control surfaces located near the fuselage and in the middle of the wing are respectively connected to servo motor I and servo motor II arranged in the fuselage or wing.

[0007] Preferably, a Y-shaped main spars are provided at the quarter-chord of the wing; The main beam is provided with multiple ribs at predetermined intervals.

[0008] Preferably, acceleration sensor I, acceleration sensor II, and acceleration sensor III are respectively arranged at the wingtip, the leading edge of the wing root, and the trailing edge of the wing root.

[0009] Preferably, strain gauge I, strain gauge II, strain gauge III, and strain gauge VI are respectively arranged at both ends of the main beam and at the Y-shaped connection.

[0010] Preferably, angle encoder I and angle encoder II are respectively installed on the rudder shafts of servo motor I and servo motor II.

[0011] Preferably, the surface of the test model body is encapsulated with carbon fiber skin, and the interior of the test model body is filled with foam.

[0012] The present invention has at least the following beneficial effects: The present invention comprehensively considers the shape of the high aspect ratio aircraft, the design of the active load mitigation structure to be simulated, and the space design of the servo position required for the drive control surface, etc., and provides a reliable and feasible design scheme for the high aspect ratio aircraft high-speed wind tunnel load active mitigation test model. It can effectively solve the design problem of matching the structure and the position of the actuating servo in the high-speed wind tunnel load active mitigation aeroelastic test model.

[0013] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0014] Figure 1 A schematic diagram of the overall shape of the full-model design scheme for the active load mitigation test model of a high-aspect-ratio aircraft in a high-speed wind tunnel; Figure 2 A schematic diagram of the overall shape of a high-aspect-angle aircraft high-speed wind tunnel load active mitigation test model; Figure 3 for Figure 2 A schematic diagram of the cross-section at mark A in the middle; Figure 4 for Figure 2 A schematic diagram of the cross-section at mark B in the middle; Figure 5 for Figure 2 A schematic diagram of the cross-section at the C mark; Figure 6 Schematic diagram of the internal structure of a test model for active load mitigation in high-speed wind tunnels for aircraft with high aspect ratio; Figure 7 for Figure 6 A schematic diagram of the cross-section at the D mark in the middle; Figure 8 for Figure 6 A schematic diagram of the cross-section at mark B in the middle; Figure 9 for Figure 6 A schematic diagram of the cross-section at the E mark in the middle; Figure 10 A cross-sectional schematic diagram of the main beam, foam filling, and skin structure inside the test model for actively mitigating the load in a high-speed wind tunnel for aircraft with a high aspect ratio. Figure 11 This refers to the aerodynamic mesh of the wing section in the simulation experiment of this invention; Figure 12 This is the structural mesh of the wing section in the simulation experiment of this invention; Figure 13This represents one of the deformation states of the wing section in the simulation experiment of this invention; Figure 14 This is another deformation state of the wing part in the simulation experiment of this invention; Among them, 1-main body of the test model; 2-deflection control surface; 3-fixed control surface; 4-servo motor I; 5-servo motor II; 6-main beam; 7-rib plate; 8-accelerometer I; 9-accelerometer II; 10-accelerometer III; 11-strain gauge I; 12-strain gauge II; 13-strain gauge III; 14-strain gauge VI; 15-angle encoder I; 16-angle encoder II; 17-linear servo motor connecting rod; 18-carbon fiber skin; 19-foam. Detailed Implementation

[0015] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0016] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0017] It should be noted that in the description of this invention, the orientations or positional relationships indicated by terms are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention. In addition, the terms "I" and "II" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0018] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed", "equipped", "sleeved / connected", "connected", etc., should be interpreted broadly. For example, "connection" 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 a connection within two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0019] like Figures 1-10 As shown, the main body 1 of the test model mainly includes, in terms of structure, a deflection control surface 2, a fixed control surface 3, a servo motor I 4, a servo motor II 5, a main beam 6, a rib plate 7, an acceleration sensor, multiple strain gauges, multiple angle encoders, a linear servo motor linkage 17, a carbon fiber skin 18, and foam for filling, etc.

[0020] The test model simulates the left half of a high aspect ratio aircraft (viewed from the nose to the tail), including the fuselage fairing section. The root of the fuselage fairing section of the test model is fixed to the side wall support device inside the wind tunnel test section.

[0021] Structurally, the main body of the test model 1 has a single swept leading edge. The fuselage, wings, and wing-body transition sections all adopt the NACA0012 airfoil, exhibiting a symmetrical structure. The cross-sections are identical at all points on the wing (it should be noted that in each figure, A is the cross-section at the wing root, B is the cross-section at the wing midsection, C is the cross-section near the wingtip, the cross-section at D shows the two beams of the Y-shaped beam, and the cross-section at E near the wingtip shows only the main beam of the Y-shaped beam). The wing trailing edge is designed with three control surfaces. The one near the outer edge of the wing is a fixed, non-rotatable control surface 3, connected to the wing body via a replaceable variable-angle connector, enabling tests at different angles. The ones near the fuselage and in the middle are rotatable deflecting control surfaces 2, directly driven by servo motors I 4 and II 5 located within the fuselage and wing. In practical applications, the control surfaces in the middle of the wing and near the fuselage are directly driven by servo motors and rudder shafts for deflection. Servo I4, located near the fuselage wing control surfaces, is designed inside the fuselage. Since the fuselage only serves a rectification function and has ample internal space, the space for the servo driving the wing control surfaces near the fuselage is sufficient to meet the power design requirements. Servo II5, located on the middle control surface, is fixed between the Y-shaped main beams 6 and directly drives the control surface deflection through the servo's output shaft and the control surface's rotation shaft.

[0022] Inside the test model, there is a Y-shaped main beam 6, which is arranged at the quarter chord of the wing. It is mainly used to adjust the modal frequency characteristics of the test model. The Y-shaped arrangement provides enough space for the intermediate control surface servo.

[0023] Along the wing's unfolding direction, the main beam 6 has several ribs 7 spaced at predetermined intervals, perpendicular to the main beam 6 in space. These ribs serve to maintain the shape of the test model and fix the control surfaces. The spacing between the ribs 7 depends on the length of the control surfaces and the servo motor.

[0024] Accelerometer I8, Accelerometer II9, and Accelerometer III10 are respectively arranged at the wingtip, the leading edge of the wing root, and the trailing edge of the wing root to sense the model's buoyancy and pitch motion during the test.

[0025] Strain gauges I11, II12, III13, and VI14 are respectively arranged at both ends of the main beam 6 and at the Y-shaped connection to sense the elastic deformation of the main beam 6, so as to facilitate the analysis of the aeroelastic characteristics of the model during the test.

[0026] Angle encoders I15 and II16 are designed on the control surfaces in the middle of the wing and near the fuselage to provide feedback on the actual deflection state of the control surfaces.

[0027] In addition to the main beam 6, rib plate 7, each acceleration sensor, each strain gauge, servo motor, and space required for servo shaft rotation, the interior of the test model is filled with foam 19, and the surface of the test model is covered with high-strength carbon fiber skin 18 to maintain its shape. The foam 19 and carbon fiber skin 18 are bonded together with adhesive suitable for the test model.

[0028] After the test model is designed and manufactured, it is fixed to the side wall support device inside the wind tunnel test section by the fuselage root, and can then be used to carry out aeroelastic testing related to an active load mitigation test model for high-speed wind tunnel aircraft with a large aspect ratio. Based on the semi-model test model designed in this invention, by further reducing the model scale and making it symmetrical, a full-model active load mitigation aeroelastic test model can be obtained.

[0029] Verification example: To verify the effectiveness of this invention, this verification example uses... Figure 6 Numerical simulation verification was conducted using the wing in the semi-modal test model as the research object. First, aerodynamic meshes were generated based on the wing's structural shape, such as... Figure 11 As shown, the aerodynamic loads of the structure are solved; then, the wing structure is meshed, as shown. Figure 12 As shown, this is used to solve its dynamic characteristics; in addition, spline interpolation is required between the structural mesh and the aerodynamic mesh to ensure that the aerodynamic loads can act on the wing structure. Given the incoming flow input conditions under the corresponding operating conditions, the dynamic characteristics can be obtained by calculating the aerodynamic loads and the vibration response of the wing structure under the loads, as shown. Figure 13 and 14 These are the torsional and bending vibration modes of the wing structure. By comparing the aeroelastic characteristics of the experimental model with the design target, and by adjusting the cross-section of the main beam or appropriately increasing the counterweight, the aeroelastic characteristics of the model can be made closer to the design target. Then, the model can be fabricated according to the above model design scheme.

[0030] The above solution is merely an illustration of a preferred example and is not limited thereto. When implementing this invention, appropriate substitutions and / or modifications can be made according to the user's needs.

[0031] The number of devices and processing scale described herein are for the purpose of simplifying the description of the invention. Applications, modifications, and variations of the invention will be readily apparent to those skilled in the art.

[0032] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. It can be applied to various fields suitable for the present invention. Other modifications can be readily made by those skilled in the art. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and examples shown and described herein.

Claims

1. A high-aspect-ratio aircraft high-speed wind tunnel load active mitigation test model, characterized in that, The leading edge of the main body of the test model is single swept, and the cross sections of the fuselage, wings and wing-body transition are all NACA0012 airfoil, with a symmetrical structure. The trailing edge of the wing is provided with three control surfaces. Among them, the control surface located on the outer side of the wing is a fixed control surface, which is connected to the wing body through a replaceable variable angle connector. The two deflection control surfaces located near the fuselage and in the middle of the wing are respectively connected to servo motor I and servo motor II arranged in the fuselage or wing. A Y-shaped main spars are installed at the quarter-chord of the wing; Among them, servo motor I is designed inside the fuselage, and servo motor II is fixed between the Y-shaped main beams; Strain gauges I, II, III, and VI are respectively arranged at both ends of the main beam and at the Y-shaped connection.

2. The high-aspect-ratio aircraft high-speed wind tunnel load active mitigation test model as described in claim 1, characterized in that, Multiple ribs are arranged at predetermined intervals on the main beam.

3. The high-aspect-ratio aircraft high-speed wind tunnel load active mitigation test model as described in claim 1, characterized in that, Acceleration sensor I, acceleration sensor II, and acceleration sensor III are respectively arranged at the wingtip, the leading edge of the wing root, and the trailing edge of the wing root.

4. The high-aspect-ratio aircraft high-speed wind tunnel load active mitigation test model as described in claim 1, characterized in that, Angle encoder I and angle encoder II are respectively installed on the rudder shafts of servo motor I and servo motor II.

5. The high-aspect-ratio aircraft high-speed wind tunnel load active mitigation test model as described in claim 1, characterized in that, The surface of the test model body is encapsulated with carbon fiber skin, and the interior of the test model body is filled with foam.

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