Mach number variable nozzle device

Abstract

The application relates to the technical field of wind tunnel equipment, and discloses a variable-Mach-number nozzle device which comprises an external shell, a nozzle shell, adjusting components and pressure equipment; the nozzle shell is arranged in the external shell and is provided with a pressure adjusting cavity and an airflow channel; the bottom wall of the pressure adjusting cavity is a flexible wall I, and a flexible wall II is arranged between the pressure adjusting cavity and the airflow channel; the adjusting components are arranged in a plurality of groups, the fixed ends of the adjusting components are connected to the nozzle shell, the adjusting ends of the adjusting components penetrate through the flexible wall I and are fixed to the flexible wall I, and the adjusting ends are connected to the flexible wall II; the pressure equipment is connected to the pressure adjusting cavity of the nozzle shell and is used for adjusting the pressure in the pressure adjusting cavity; the passive deformation form is adopted, the pressure change is realized by extruding cooling water with high-pressure gas, the moving end of the adjusting component is driven to move through the flexible wall I, the flexible wall II is adjusted, and the deformation of the gas channel is completed; only the cooling water pressure is adjusted during the adjusting process, the adjusting amount is small, the elements are single, and the adjusting precision is high.

Description

Technical Field

[0001] This invention belongs to the field of wind tunnel equipment technology, and particularly relates to a nozzle device for simulating changes in Mach number. Background Technology

[0002] Hypersonic vehicles represent the most advanced aerospace technology in the world today and are one of the key technologies that developed countries are focusing on developing. Hypersonic wind tunnel testing can simulate real aerospace flight conditions on the ground. Compared with actual flight testing, it has a series of advantages such as high success rate, good repeatability, more test data, low cost and low risk. It is the foundation for conducting flight tests and developing real aircraft, and is also an indispensable key equipment for the development of related technologies.

[0003] Hypersonic vehicles typically fly at Mach numbers greater than 5, resulting in extremely high inlet temperatures. Due to material strength limitations, fixed nozzles are commonly used in wind tunnel tests. However, fixed nozzle tests are short-lived, and nozzle replacement is costly, limiting tests to a fixed Mach number and hindering rapid technological development. Many research institutions both domestically and internationally have adopted flexible nozzles with two-dimensional variable profiles. Hydraulic or electric actuation mechanisms are installed on the upper and lower walls or one side wall. During testing, the profile is adjusted according to a preset program to regulate the Mach number. However, this structural design, especially the actuation mechanism, is complex and difficult to adjust. Furthermore, for hypersonic simulations, the high temperatures limit the material strength of the flexible walls, and the actuation mechanism is affected by temperature, leading to issues related to material strength, cooling and heat transfer, and wall sealing. Existing domestic literature indicates that no effective solutions for nozzle cooling have yet been proposed.

[0004] Adjustable Mach number nozzles are typically used for low-Mach number flight wind tunnel tests. Although they allow for Mach number adjustment, they have the following main drawbacks when applied to hypersonic simulations:

[0005] 1. Numerous actuating mechanisms, poor reliability, and complex adjustment system;

[0006] 2. Due to the high temperature, the flexible wall surface needs to be cooled while maintaining flexible movement under the action of the actuation mechanism, which makes the system design extremely difficult.

[0007] 3. During the movement of the flexible wall, the movement distance of the actuating mechanism at each position is different, and there are mutual constraints and influences. Summary of the Invention

[0008] The present invention aims to provide a nozzle device with variable Mach number to solve at least one of the problems mentioned in the background art.

[0009] To solve the above-mentioned technical problems, the specific technical solution of the present invention is as follows:

[0010] In some embodiments of this application, a nozzle device with variable Mach number is provided, comprising:

[0011] outer casing,

[0012] The nozzle housing is disposed inside the outer housing and has a pressure regulating chamber and an airflow channel. The bottom wall of the pressure regulating chamber is a flexible wall one, and a flexible wall two is provided between the pressure regulating chamber and the airflow channel.

[0013] The adjustment components are provided in several parts, and the fixed ends of all parts are connected to the nozzle housing. The adjustment ends are fixed through the first flexible wall and are respectively connected to the second flexible wall.

[0014] A pressure device, connected to the pressure regulating chamber of the nozzle housing, is used to regulate the pressure within the pressure regulating chamber.

[0015] In the preferred embodiment of the above-mentioned variable Mach number nozzle device, the nozzle housing consists of a buffer chamber, a pressure regulating chamber, a transition chamber, and an airflow channel from top to bottom. The buffer chamber and the pressure regulating chamber are connected. The fixed end of the adjusting component is connected to the partition between the buffer chamber and the pressure regulating chamber, and the bottom end of its adjusting end penetrates through the first flexible wall and is connected to the corresponding side of the second flexible wall. The transition chamber and the airflow channel are separated by the second flexible wall.

[0016] In the preferred embodiment of the above-mentioned variable Mach number nozzle device, the front end of the flexible wall II is fixed to the inner wall of the gas flow front end of the gas channel, and the other end overlaps with the inner wall of the gas flow rear end, and its side wall slides and seals with the side wall of the nozzle housing.

[0017] In the preferred embodiment of the above-mentioned variable Mach number nozzle device, the buffer chamber is connected to the pressure device through an inlet pipe, and an air collection groove and an exhaust valve connected thereto are provided on its top wall.

[0018] The pressure regulating chamber has a pressure relief port on the corresponding side wall.

[0019] In the preferred embodiment of the above-mentioned nozzle device with variable Mach number, the buffer chamber, pressure regulating chamber, transition chamber and regulating component are respectively arranged symmetrically with respect to the gas channel.

[0020] In the preferred embodiment of the above-mentioned variable Mach number nozzle device, the elastic modulus of several of the adjustment components is different, and the displacement generated by their adjustment ends under the same pressure is different.

[0021] In the preferred embodiment of the above-mentioned variable Mach number nozzle device, when the pressure in the pressure regulating chamber increases, the first flexible wall moves towards the gas channel under the pressure, causing the regulating end of the corresponding regulating component to extend, thereby pushing the second flexible wall to move, and the diameter of the gas channel undergoes corresponding deformation.

[0022] When the pressure inside the pressure regulating chamber decreases, the first flexible wall moves in the opposite direction, causing the regulating end of the corresponding regulating component to shorten, which in turn pulls the second flexible wall to move in the opposite direction, causing the diameter of the gas channel to deform accordingly.

[0023] In a preferred embodiment of the aforementioned variable Mach number nozzle device, the adjusting component includes:

[0024] A guide rod, one end of which is fixed to the partition between the buffer chamber and the pressure regulating chamber, and the other end of which faces the gas passage;

[0025] The movable rod is sleeved on the guide rod and slidably connected to it;

[0026] An elastic element is sleeved on the guide rod, with one end connected to the partition between the buffer chamber and the pressure regulating chamber, and the other end connected to the corresponding end of the movable rod;

[0027] The hinged support has its fixed end connected to the corresponding end of the movable rod, and its hinged end connected to the flexible wall.

[0028] In the preferred embodiment of the above-mentioned variable Mach number nozzle device, the medium solution is squeezed by compressed air in the storage component of the pressure device, so that the medium solution enters the corresponding buffer chamber and pressure regulating chamber through the inlet pipe respectively.

[0029] In the preferred embodiment of the above-mentioned nozzle device with variable Mach number, the pressurizing device is equipped with a pressure regulating valve, and the inlet pipe is equipped with a switching valve.

[0030] As can be seen from the above technical solution, compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] This application employs a passive deformation method, using high-pressure gas to compress cooling water to achieve pressure changes, thereby ensuring uniform force on the first flexible wall. This, in turn, moves the actuating end of the adjusting component, adjusting the second flexible wall and thus completing the deformation of the gas channel. During the adjustment process, the elastic element is immersed in the cooling water, ensuring that the elastic modulus remains unchanged and guaranteeing the adjustment accuracy. The adjustment process only involves adjusting the cooling water pressure, resulting in a small adjustment amount, a single element, and high control precision.

[0032] By using prefabricated elastic elements with different elastic moduli, different deformation amounts can be achieved under the same stress conditions, thereby enabling the flexible wall surface to change shape according to a predetermined target; by calculating the deformation amount of different elastic elements under different stress conditions in advance, high-precision gas channels can be obtained, thus improving the reliability of the solution. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the structure of the present invention;

[0035] Figure 2 This is a schematic diagram of the nozzle principle in this invention;

[0036] Figure 3 for Figure 2 A cross-sectional view along the AA direction;

[0037] Figure 4 This is a schematic diagram of the adjusting component in this invention.

[0038] In the picture:

[0039] 1. Outer shell; 2. Nozzle shell; 20. Pressure regulating chamber; 21. Airflow channel; 22. Flexible wall one; 23. Flexible wall two; 24. Buffer chamber; 3. Adjusting component; 30. Guide rod; 31. Movable rod; 32. Elastic element; 33. Hinge support; 4. Pressure equipment; 5. Exhaust valve; 6. Drain valve. Detailed Implementation

[0040] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0041] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and 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. Therefore, they should not be construed as limitations on this application.

[0042] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0043] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0044] To better understand the purpose, structure, and function of this invention, the invention will be described in further detail below with reference to the accompanying drawings.

[0045] See Figure 1-4 As shown, some embodiments of this application are described, providing a nozzle device with variable Mach number, including: an outer housing 1, a nozzle housing 2, an adjusting component 3, and a pressure device 4; wherein,

[0046] The nozzle housing 2 is located inside the outer housing 1 and has a pressure regulating chamber 20 and an airflow channel 21. The bottom wall of the pressure regulating chamber 20 is a flexible wall 22, and a flexible wall 23 is provided between the pressure regulating chamber 20 and the airflow channel 21. Several regulating components 3 are provided, and their fixed ends are all connected to the nozzle housing 2. The regulating ends are all fixed through the flexible wall 22 and are respectively connected to the flexible wall 23. The pressure device 4 is connected to the pressure regulating chamber 20 of the nozzle housing 2 and is used to regulate the pressure inside the pressure regulating chamber 20.

[0047] Specifically, the outer shell 1 is mainly used to fix and support the nozzle shell, and the inside is a connecting cavity, in which the nozzle shell 2 is located.

[0048] Specifically, the top wall of the nozzle housing 2 is connected to the top inner wall of the outer housing 1, and a connecting hole is opened on the support plate between the buffer chamber 24 and the pressure regulating chamber 20; the flexible wall 23 is slidably connected to the two wall plates of the nozzle housing 2.

[0049] In a preferred embodiment of the above, the nozzle housing 2 consists of a buffer chamber 24, a pressure regulating chamber 20, a transition chamber, and an airflow channel 21 from top to bottom. The buffer chamber 24 and the pressure regulating chamber 20 are connected. The fixed end of the adjusting component 3 is connected to the partition between the buffer chamber 24 and the pressure regulating chamber 20. The bottom end of its adjusting end passes through the first flexible wall 22 and is connected to the corresponding side of the second flexible wall 23. The transition chamber and the airflow channel 21 are separated by the second flexible wall 23.

[0050] In the preferred embodiment described above, the front end of the flexible wall 23 is fixed to the inner wall of the airflow direction of the gas channel 21, and the other end overlaps with the inner wall of the airflow direction of the rear end. Its side wall slides and seals with the side wall of the nozzle housing 2, which can ensure that the movement of the wall panel is unrestricted when it deforms, and achieve higher adjustment accuracy.

[0051] In the preferred embodiment above, the buffer chamber 24 is connected to the pressure device 4 through the liquid inlet pipe, and an air collection groove and an exhaust valve 5 connected thereto are provided on its top wall. If boiling occurs, or air enters during high-pressure water extrusion, it can be centrally discharged through the upper exhaust valve 5.

[0052] The pressure regulating chamber 20 has a pressure relief port on the corresponding side wall, and a drain valve 6 is installed at the pressure relief port.

[0053] It should be noted that after the test begins, the air supply in the nozzle is adjusted according to the test plan, and the appropriate temperature and pressure are adjusted. Then, the pressure of the extruded air from the high-pressure water is adjusted until the nozzle profile meets the predetermined requirements. At this time, the Mach number at the nozzle outlet can be calculated by the total static pressure / total static temperature to determine whether the design requirements are met. After the test, the test air in the nozzle is gradually shut off first, then the extruded air supply valve is closed, and the drain valve 6 is opened to gradually drain the water in the water tank. The test is then completed.

[0054] In the preferred embodiment described above, the buffer chamber 24, the pressure regulating chamber 20, the transition chamber, and the regulating component 3 are symmetrically arranged with the gas channel 21 as the center.

[0055] In the preferred embodiment described above, the elastic modulus of the several adjusting components 3 are different, and the displacement generated by their adjusting ends under the same pressure is different.

[0056] It should be noted that before the test, calculations need to be performed in advance based on the target Mach number of the test. The required nozzle profile shape is calculated theoretically, and then the required deformation of each adjustment component 3 is calculated. The required water supply pressure is determined based on the deformation, and then the pressure is adjusted using pressurization equipment to simulate the preset sprinkler irrigation device.

[0057] In the preferred embodiment above, when the pressure in the pressure regulating chamber 20 increases, the flexible wall 22 moves toward the gas channel 21 under the action of pressure, causing the regulating end of the corresponding regulating component 3 to extend, thereby pushing the flexible wall 23 to move, and the diameter of the gas channel 21 undergoes corresponding deformation.

[0058] When the pressure in the pressure regulating chamber 20 decreases, the flexible wall 22 moves in the opposite direction, causing the regulating end of the corresponding regulating component 3 to shorten, which in turn pulls the flexible wall 23 to move in the opposite direction, causing the diameter of the gas channel 21 to deform accordingly.

[0059] In a preferred embodiment of the above embodiments, the adjusting component 3 includes:

[0060] The guide rod 30 has one end fixed to the partition between the buffer chamber 24 and the pressure regulating chamber 20, and the other end faces the gas channel 21.

[0061] The movable rod 31 is sleeved on the guide rod 30 and slidably connected to it;

[0062] The elastic element 32 is sleeved on the guide rod 30, with one end connected to the partition between the buffer chamber 24 and the pressure regulating chamber 20, and the other end connected to the corresponding end of the movable rod 31.

[0063] The hinge support 33 has its fixed end connected to the corresponding end of the movable rod 31, and its hinged end connected to the flexible wall 23.

[0064] It should be noted that under the action of force, all the adjusting components 3 will move; that is, the movable rod 31 will move along the guide rod 30. The amount of displacement will be affected by the deformation of the elastic element 32. The elastic element 32 can be in the form of a spring, diaphragm, etc. When different elastic moduli are selected, the amount of deformation will be different, so the flexible wall panel will exhibit uneven deformation. This produces the expected throat shape. Furthermore, since all elastic elements are submerged in water at a constant temperature, they will not be affected by temperature, which helps to ensure the accuracy of the simulation.

[0065] In a preferred embodiment of the above-described embodiment, the medium solution is compressed by compressed air within the storage component of the pressure device 4, causing the medium solution to enter the corresponding buffer chamber 24 and pressure regulating chamber 20 through the inlet pipe, respectively.

[0066] In a preferred embodiment of the above-described embodiment, the pressurizing device is equipped with a pressure regulating valve, and an on / off valve is provided on the inlet pipe.

[0067] It should be noted that the pressurizing equipment has a pressure chamber containing cooling water. The inlet of the pressure chamber is connected to a high-pressure air compressor unit, and the outlet is connected to the buffer chamber 24. It can pressurize the internal cooling water by compressing high-pressure air, thereby changing the pressure in the pressure regulating chamber 20. A high-pressure air compressor unit can be used to store the water in a high-pressure air tank, typically with a storage pressure of 22-32 MPa. Inspect the air supply lines, high-pressure water tank, and water supply lines.

[0068] As can be seen from the above technical solution, compared with the prior art, the beneficial effects of the present invention are as follows:

[0069] This application employs a passive deformation method, using high-pressure gas to compress cooling water to achieve pressure changes, thereby ensuring uniform force on the flexible wall 22. This, in turn, moves the actuating end of the adjusting component 3, adjusting the flexible wall 23 and thus completing the deformation of the gas channel 21. During the adjustment process, the elastic element 32 is immersed in the cooling water, ensuring that the elastic modulus remains unchanged and guaranteeing the adjustment accuracy. The adjustment process only involves adjusting the cooling water pressure, resulting in a small adjustment amount, a single element, and high control precision.

[0070] By using prefabricated elastic elements 32 with different elastic moduli, different deformation amounts can be achieved under the same stress conditions, thereby enabling the flexible wall surface to change shape according to a predetermined target; by calculating the deformation amounts of different elastic elements under different stress conditions in advance, a high-precision gas channel 21 can be obtained, thus improving the reliability of the solution.

[0071] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0072] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A nozzle device with variable Mach number, characterized in that, include: outer casing, The nozzle housing is disposed inside the outer housing and has a pressure regulating chamber and an airflow channel. The bottom wall of the pressure regulating chamber is a flexible wall one, and a flexible wall two is provided between the pressure regulating chamber and the airflow channel. The adjustment components are provided in several parts, and the fixed ends of all parts are connected to the nozzle housing. The adjustment ends are fixed through the first flexible wall and are respectively connected to the second flexible wall. A pressure device, connected to a pressure regulating cavity in the nozzle housing, is used to regulate the pressure within the pressure regulating cavity; The nozzle housing consists of a buffer chamber, a pressure regulating chamber, a transition chamber, and an airflow channel from top to bottom. The buffer chamber and the pressure regulating chamber are connected. The fixed end of the adjusting component is connected to the partition between the buffer chamber and the pressure regulating chamber, and the bottom end of its adjusting end penetrates through the first flexible wall and is connected to the corresponding side of the second flexible wall. The transition chamber and the airflow channel are separated by the second flexible wall. The front end of the flexible wall is fixed to the inner wall of the airflow channel at the front end, and the other end overlaps with the inner wall of the airflow channel at the rear end. Its side wall slides and seals with the side wall of the nozzle housing. The adjusting component includes: A guide rod, one end of which is fixed to the partition between the buffer chamber and the pressure regulating chamber, and the other end of which faces the airflow channel; The movable rod is sleeved on the guide rod and slidably connected to it; An elastic element is sleeved on the guide rod, with one end connected to the partition between the buffer chamber and the pressure regulating chamber, and the other end connected to the corresponding end of the movable rod; A hinged support, the fixed end of which is connected to the corresponding end of the movable rod, and the hinged end of which is connected to the flexible wall. The storage device of the pressure device uses compressed air to compress the medium solution, causing the medium solution to enter the corresponding buffer chamber and pressure regulating chamber through the inlet pipe.

2. The variable Mach number nozzle device according to claim 1, characterized in that, The buffer chamber is connected to the pressure device through an inlet pipe, and an air collection groove and an exhaust valve connected thereto are provided on its top wall. The pressure regulating chamber has a pressure relief port on the corresponding side wall.

3. The variable Mach number nozzle device according to claim 1, characterized in that, The buffer chamber, pressure regulating chamber, transition chamber, and regulating components are symmetrically arranged with respect to the airflow channel.

4. A nozzle device with variable Mach number according to claim 3, characterized in that, The elastic modulus of the various adjustment components is different, and the displacement produced by their adjustment ends under the same pressure is different.

5. A nozzle device with variable Mach number according to claim 4, characterized in that, When the pressure inside the pressure regulating chamber increases, the first flexible wall moves toward the airflow channel under the pressure, causing the regulating end of the corresponding regulating component to extend, thereby pushing the second flexible wall to move, and the diameter of the airflow channel deforms accordingly. When the pressure inside the pressure regulating chamber decreases, the first flexible wall moves in the opposite direction, causing the regulating end of the corresponding regulating component to shorten, which in turn pulls the second flexible wall to move in the opposite direction, causing the diameter of the airflow channel to deform accordingly.

6. A nozzle device with variable Mach number according to claim 1, characterized in that, The pressure device is equipped with a pressure regulating valve, and the liquid inlet pipe is equipped with a switch valve.

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