A pulsating pressure test model of elastic wing and manufacturing method thereof

Abstract

An elastic wing pulsating pressure test model and a manufacturing method, the test model includes an elastic model body, at least one cover plate and at least one pressure sensor, the model body is provided with a plurality of strip grooves, each groove extends along the length direction of the model body, and is sequentially arranged along the width direction of the model body; each groove is filled with a hard filling material, at least one pressure sensor is arranged in the hard filling material filled in a groove by fixing the filler, the surface of each pressure sensor is covered by a cover plate, the cover plate is provided with a through hole, and the head of the pressure sensor is exposed through the through hole. The elastic wing pulsating pressure test model of the present invention uses an elastic model to measure the pulsating pressure, considering the influence of the fluid-solid coupling effect, and the obtained result is closer to the real flight environment; the additional mass and additional stiffness provided by the hard filling material filled in the model body, the small sensor, and the cover plate are very small, which can make the test result more accurate.

Description

Technical Field

[0001] The invention belongs to the field of aerospace testing technology, and more specifically, relates to an elastic wing pulsation pressure test model and a manufacturing method. Background Art

[0002] As the excitation source of the aircraft structure response and the source of aerodynamic noise, pulsating pressure is one of the important contents in the study of aircraft aerodynamics. The study of pulsating pressure loads began in my country in the 1960s. The relevant wind tunnel test technology has become a mature research method and has gradually been valued by aviation and aerospace model design. The current common pulsating pressure measurement technology is to use a rigid scaled model to conduct test measurements in a wind tunnel. The model must meet the geometric similarity criterion. The test element is a high-precision, wide-band response, fast-response dynamic pressure sensor, which is installed in a way that the head is flush with the model surface. The pulsating pressure measurement test requires model rigidity. During the test, the model cannot be completely rigid. It is usually required that the connection between the model and the support mechanism, and between the support mechanism and the wind tunnel tool holder be as close to the fixed support condition as possible, and the natural frequency of the entire model structure system supported in the wind tunnel must be higher than the upper limit of the unsteady pressure load. However, in actual flight environments, if the frequency of the pulsating pressure on the wing is very close to the low-order frequency of the structure, fluid-solid coupling will occur. The pulsating pressure environment at this time will be significantly different from the results obtained by measuring the rigid model in the wind tunnel. The wind tunnel test results used for load and noise environment assessment are distorted to a large extent.

[0003] Therefore, a method for manufacturing an elastic wing pulsation pressure test model is needed to solve the above problems. Summary of the invention

[0004] The purpose of the present invention is to provide an elastic wing pulsation pressure test model and a manufacturing method to solve the problem of large distortion in load and noise environment assessment caused by fluid-solid coupling phenomenon during wind tunnel testing.

[0005] In order to achieve the above-mentioned purpose, the present invention provides an elastic wing pulsation pressure test model, including a model body, at least one cover plate and at least one pressure sensor, the model body is provided with a plurality of strip grooves, each of the grooves extends along the length direction of the model body, and is arranged in sequence along the width direction of the model body; each of the grooves is filled with a hard filling material, at least one pressure sensor is arranged in the hard filling material filled in one of the grooves through a fixed filler, the surface of each of the pressure sensors is covered by a cover plate, the cover plate is provided with a through hole, and the head of the pressure sensor is exposed from the through hole.

[0006] Preferably, the pressure sensor is a disc-type pulsating pressure sensor, the depth of the groove is not less than the thickness of the pressure sensor, and the width of the groove is not less than the diameter of the pressure sensor.

[0007] Preferably, the head of the pressure sensor does not extend beyond the surface of the model body; and / or,

[0008] The difference between the diameter of the through hole of the cover plate and the diameter of the pressure sensor head is no more than 0.1 mm.

[0009] Preferably, the cover sheet has a thickness of 0.2-0.5 mm, and is connected to the hard filling material, at least covering the area where the pressure sensor is located and does not exceed the range of the groove.

[0010] Preferably, the hard filling material is hard foam, the cover sheet is made of metal, and the fixed filler is soft filler.

[0011] Preferably, at least one end of the groove where the at least one pressure sensor is provided is provided with a signal line hole, and the signal line of the pressure sensor passes through the signal line hole.

[0012] The present invention also provides a method for manufacturing the above-mentioned elastic wing pulsating pressure test model, comprising:

[0013] Step 1: Calculate and obtain the first-order frequency of the test model according to the first-order frequency of the real wing structure;

[0014] Step 2, selecting a model material to form a simulation model through three-dimensional modeling, opening the grooves on the simulation model, and adjusting the number and position of the grooves so that the natural frequency of the simulation model is the same as the first-order frequency of the test model;

[0015] Step 3, forming the model material according to the simulated model after slotting to form the model body, and placing the pressure sensor and its signal line in the groove;

[0016] Step 4: Fill the groove with the hard filling material, reserve a fixed space at the pressure sensor and its signal line, and polish the hard filling material to make the model body consistent with the aerodynamic shape of the real wing structure;

[0017] Step 5: Fill the fixed space with a fixing filler to fix the pressure sensor, and arrange a cover sheet on the top of the fixed space to close the fixed space, so that the head of the pressure sensor is exposed from the through hole.

[0018] Preferably, in step 1: the first-order frequency of the real wing structure is obtained by performing physical tests or finite element analysis on the real wing structure, and the first-order frequency of the test model is calculated through a similarity relationship based on the first-order frequency of the real wing structure.

[0019] Preferably, the hard filling material is hard foam, the cover sheet is made of metal, the fixed filler is soft filler, and the cover sheet is bonded to the hard filling material.

[0020] Preferably, the head of the pressure sensor does not extend beyond the surface of the model body; and / or,

[0021] The difference between the diameter of the through hole and the diameter of the head of the pressure sensor is no more than 0.1 mm.

[0022] The invention relates to an elastic wing pulsating pressure test model, which has the beneficial effects of: using an elastic model to measure pulsating pressure, considering the influence of fluid-solid coupling effect, the obtained result is closer to the real flight environment; the model body is filled with hard filling materials, small sensors, and the additional mass and additional stiffness provided by the cover plate are very small, so that the test result can be more accurate.

[0023] The present invention relates to a method for manufacturing an elastic wing pulsation pressure test model. The test model manufactured by the method satisfies the dynamic similarity between the first-order structural mode of the model and the actual wing, including similar vibration shape and frequency. The design process is simple, the model processing difficulty is relatively low, the pulsation pressure sensor can be recovered after the test, and the economic benefit is good.

[0024] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0026] Figure 1 A schematic structural diagram of an elastic wing pulsating pressure test model according to an exemplary embodiment of the present invention is shown;

[0027] Figure 2 Shows Figure 1 A partial enlarged schematic diagram of

[0028] Figure 3 A cross-sectional view showing a model body in an elastic wing pulsating pressure test model according to an exemplary embodiment of the present invention;

[0029] Figure 4 A cross-sectional view of an elastic wing pulsating pressure test model according to an exemplary embodiment of the present invention is shown.

[0030] Description of reference numerals:

[0031] 1. Groove; 2. Hard filling material; 3. Cover; 4. Pressure sensor; 5. Fixed filler; 6. Model body. DETAILED DESCRIPTION

[0032] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0033] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0034] In order to solve the problems existing in the prior art, the present invention provides an elastic wing pulsating pressure test model, such as Figure 1 and Figure 4 As shown, it includes an elastic model body 6, at least one cover sheet 3 and at least one pressure sensor 4. The model body 6 is provided with a plurality of strip grooves 1, each groove 1 extends along the length direction of the model body 1, and is arranged in sequence along the width direction of the model body 1; each groove 1 is filled with a hard filling material 2, and at least one pressure sensor 4 is arranged in the hard filling material 2 filled in a groove 1 through a fixed filler 5, and the surface of each pressure sensor 4 is covered by a cover sheet 3, and the cover sheet 3 is provided with a through hole, and the head of the pressure sensor 4 is exposed through the through hole.

[0035] The elastic wing pulsating pressure test model involved in the present invention uses an elastic model to measure the pulsating pressure, taking into account the influence of the fluid-solid coupling effect, and the obtained result is closer to the actual flight environment; the model body 6 is filled with a hard filling material 2, and the additional mass and additional stiffness provided by the small sensor and the cover plate 3 are very small, so that the test result can be more accurate.

[0036] By setting the grooves 1 and adjusting the number and arrangement of the grooves 1, the test model can reach the first-order frequency of the real wing model, which is convenient for simulating the real flight environment. The grooves 1 are filled with hard filling materials 2, and the pressure sensor 4 is fixed by setting fixed fillers 5 in the grooves 1. The installation of the pressure sensor 4 does not affect the aerodynamic shape of the test model, thereby improving the accuracy of the test results.

[0037] The pressure sensor 4 is a disc-type pulsating pressure sensor, the depth of the groove 1 is not less than the thickness of the pressure sensor 4 , and the width of the groove 1 is not less than the diameter of the pressure sensor 4 .

[0038] In the present application, the groove 1 is a rectangular strip structure. By opening the groove 1 and adjusting the number, width, spacing and other related parameters of the groove 1, the first-order frequency of the test model can meet the required first-order frequency to be more in line with the actual flight state. At least one end of the groove 1 provided with at least one pressure sensor 4 is provided with a signal line hole, and the signal line of the pressure sensor 4 passes through the signal line hole.

[0039] The material of the cover sheet 3 is metal, and the metal is made into a thin sheet structure. The head of the pressure sensor 4 does not exceed the surface of the model body 6; and / or the difference between the diameter of the through hole of the cover sheet 3 and the diameter of the head of the pressure sensor 4 is not greater than 0.1mm, so that the connection between the pressure sensor 4 and the through hole of the cover sheet 3 can have a certain sealing effect. The thickness of the cover sheet 3 is 0.2-0.5mm, and it is connected to the hard filling material 2, at least covering the area where the pressure sensor 4 is located, and does not exceed the range of the groove 1. The area of ​​the cover sheet 3 should just cover the area around the pressure sensor 4, that is, the cover sheet 3 is slightly larger than the diameter of the pressure sensor 4. The cover sheet 3 is embedded in the hard filling material 2 and is flush with the surface of the hard filling material 2. The cover sheet 3 and the hard filling material 2 are connected and fixed by gluing.

[0040] The head of the pressure sensor 4 does not exceed the surface of the model body 6 , that is, the pressure sensor 4 is exposed from the through hole and is flush with or slightly concave with the surface of the cover plate 3 .

[0041] The material of the hard filling material 2 is hard foam, which is filled into the groove 1 and polished to make the test model consistent with the aerodynamic shape of the wing.

[0042] The fixed filler 5 is a soft filler, such as silicone rubber, which is filled into the groove 1 and is located below the hard filling material 2 to fix the pressure sensor 4 .

[0043] The present invention also provides a method for manufacturing the above-mentioned elastic wing pulsating pressure test model, comprising:

[0044] Step 1: Calculate and obtain the first-order frequency of the test model according to the first-order frequency of the real wing structure;

[0045] Step 2, select a model material to form a simulation model through three-dimensional modeling, open a groove 1 on the simulation model, and adjust the number and position of the groove 1 so that the natural frequency of the simulation model is the same as the first-order frequency of the test model;

[0046] Step 3: Use the model material to process and shape the simulated model after slotting to form a model body 6, and place the pressure sensor 4 and its signal line in the groove 1;

[0047] Step 4: fill the groove 1 with a hard filling material 2, reserve a fixed space at the pressure sensor 4 and its signal line, and polish the hard filling material 2 to make the model body 6 consistent with the aerodynamic shape of the real wing structure;

[0048] Step 5: Fill the fixed space with a fixed filler 5 to fix the pressure sensor 4, and arrange a cover sheet 3 on the top of the fixed space to close the fixed space, and expose the head of the pressure sensor 4 from the through hole.

[0049] The present invention adopts an elastic model to measure the pulsating pressure, which can better reflect the fluid-solid coupling effect of the flow and the wing structure vibration. The obtained pulsating pressure data is closer to the actual flight environment than the test data obtained by adopting the rigid model.

[0050] In step 1: the first-order frequency of the real wing structure is obtained by performing physical tests or finite element analysis on the real wing structure, and the first-order frequency of the test model is calculated through a similarity relationship based on the first-order frequency of the real wing structure.

[0051] The first-order frequency of the real wing structure is the first-order vibration frequency. It is a prior art to obtain the first-order frequency of the required model body 6 from the first-order frequency of the real wing structure by similarity calculation, and the specific calculation process will not be repeated here.

[0052] The manufacturing method further includes: the hard filling material 2 is hard foam, the cover sheet 3 is made of metal, the fixed filler 5 is soft filler, and the cover sheet 3 is bonded to the hard filling material 2. The head of the pressure sensor 4 does not exceed the surface of the model body 6; and / or,

[0053] The difference between the diameter of the through hole and the diameter of the head of the pressure sensor 4 is not greater than 0.1 mm.

[0054] In step 2, different model materials have different qualities and stiffnesses, so before 3D modeling, a suitable model material is selected, which can be metal. During the 3D modeling process, the natural frequency of the model is adjusted by slotting 1 to make it consistent with the first-order frequency of the test model calculated in step 1. The wing section is designed by using 3D modeling software, and slots are made at appropriate locations of the wing section so that the first-order mode of the structure of the model and the actual wing meet dynamic similarity, including similar vibration mode and frequency.

[0055] In step 3, the model material selected in step 2 is simulated and processed into a model body, which can be machined or 3D printed to obtain a model body. The model body 6 is provided with a plurality of grooves 1, and the pressure sensor 1, i.e., its signal line, is arranged using the structure of the grooves 1.

[0056] In step 4, hard foam is used as the hard filling material 2 to fill the groove 1, leaving only the position where the pressure sensor 4 is located, that is, a fixed space, and the hard foam is polished to ensure that the shape of the model body 6 is consistent with the aerodynamic shape of the real wing model, and glue is used to bond the hard foam to the model body 6.

[0057] A sheet-type pulsating pressure sensor 4 is arranged in the groove 1 of the model body 6, and then filled with hard foam, leaving only the area where the pressure sensor 4 is located to ensure the aerodynamic shape of the wing.

[0058] In step 5, a fixed filler 5, such as silicone rubber, is filled in the fixed space to fix the pressure sensor 4. The pressure sensor 4 is embedded in the hard filling material 2. The fixed filler 5 is located at the bottom of the pressure sensor 4 so that the pressure sensor 4 is connected and fixed to the groove 1 of the model body 6. The fixed filler 5 may not fully fill the fixed space. At the top of the pressure sensor 4, the cover plate 3 is embedded in the hard filling material 2 and flush with the surface of the hard filling material 2 to close the fixed space. The head of the pressure sensor 4 is exposed at the through hole of the cover plate 3 and is flush with or slightly concave with the surface of the cover plate 3. The cover plate 3 is fixed to the hard filling material 2 by bonding.

[0059] The test model obtained by the method uses an elastic model to measure the pulsating pressure, and the results obtained are closer to the real flight environment by considering the influence of the fluid-solid coupling effect; the test model is filled with foam material, a small sensor, and the cover 3 made of thin metal provide small additional mass and additional stiffness, which can make the test results more accurate. The first-order mode of the structure of the test model and the actual wing meets the dynamic similarity, including the vibration shape and frequency. The design process is simple, the model processing difficulty is low, the pulsating pressure sensor can be recycled after the test, and the economic benefit is good.

[0060] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. An elastic wing pulsating pressure test model, characterized in that: The invention comprises an elastic model body (6), at least one cover sheet (3) and at least one pressure sensor (4); the model body (6) is provided with a plurality of strip-shaped grooves (1), each of the grooves (1) extending along the length direction of the model body (1) and arranged in sequence along the width direction of the model body (1); each of the grooves (1) is filled with a hard filling material (2); at least one of the pressure sensors (4) is arranged in the hard filling material (2) filled in one of the grooves (1) through a fixed filler (5); the surface of each of the pressure sensors (4) is covered by one of the cover sheets (3); the cover sheet (3) is provided with a through hole, and the head of the pressure sensor (4) is exposed from the through hole.

2. The elastic wing pulsating pressure test model according to claim 1, characterized in that: The pressure sensor (4) is a disc-type pulsating pressure sensor, the depth of the groove (1) is not less than the thickness of the pressure sensor (4), and the width of the groove (1) is not less than the diameter of the pressure sensor (4).

3. The elastic wing pulsating pressure test model according to claim 2, characterized in that: The head of the pressure sensor (4) does not extend beyond the surface of the model body (6); and / or, The difference between the diameter of the through hole of the cover plate (3) and the diameter of the head of the pressure sensor (4) is no more than 0.1 mm.

4. The elastic wing pulsating pressure test model according to claim 2, characterized in that: The thickness of the cover sheet (3) is 0.2-0.5 mm, and the cover sheet (3) is connected to the hard filling material (2), at least covers the area where the pressure sensor (4) is located, and does not exceed the range of the groove (1).

5. The elastic wing pulsating pressure test model according to claim 2, characterized in that: The hard filling material (2) is hard foam, the cover sheet (3) is made of metal, and the fixed filler (5) is soft filler.

6. The elastic wing pulsating pressure test model according to claim 1, characterized in that: At least one end of the groove (1) provided with the at least one pressure sensor (4) is provided with a signal line hole, and the signal line of the pressure sensor (4) passes through the signal line hole.

7. A method for manufacturing an elastic wing pulsating pressure test model according to claim 1, characterized in that: include: Step 1: Calculate and obtain the first-order frequency of the test model according to the first-order frequency of the real wing structure; Step 2, selecting a model material to form a simulation model through three-dimensional modeling, opening the grooves (1) on the simulation model, and adjusting the number and position of the grooves (1) so that the natural frequency of the simulation model is the same as the first-order frequency of the test model; Step 3, using the model material to process and shape the simulation model after slotting to form the model body (6), and placing the pressure sensor (4) and its signal line in the groove (1); Step 4: Fill the groove (1) with the hard filling material (2), reserve a fixed space at the pressure sensor (4) and its signal line, and polish the hard filling material (2) so that the model body (6) is consistent with the aerodynamic shape of the real wing structure; Step 5: Fill the fixed space with a fixing filler (5) to fix the pressure sensor (4), and arrange a cover sheet (3) on the top of the fixed space to close the fixed space, and expose the head of the pressure sensor (4) from the through hole.

8. The method for manufacturing an elastic wing pulsating pressure test model according to claim 7, characterized in that: In the step 1: the first-order frequency of the real wing structure is obtained by performing physical tests or finite element analysis on the real wing structure, and the first-order frequency of the test model is calculated through a similarity relationship based on the first-order frequency of the real wing structure.

9. The method for manufacturing an elastic wing pulsating pressure test model according to claim 7, characterized in that: The hard filling material (2) is hard foam, the cover sheet (3) is made of metal, the fixed filler (5) is soft filler, and the cover sheet (3) is bonded to the hard filling material (2).

10. The method for manufacturing an elastic wing pulsating pressure test model according to claim 7, characterized in that: The head of the pressure sensor (4) does not extend beyond the surface of the model body (6); and / or, The difference between the diameter of the through hole and the diameter of the head of the pressure sensor (4) is no more than 0.1 mm.

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