Nozzle throat structure of supersonic high-temperature wind tunnel

Abstract

The invention provides a nozzle throat structure of a supersonic high-temperature wind tunnel, which relates to the technical field of nozzle throats, and comprises an inner shell, and a nozzle which is gradually shrunk and then gradually expanded from one end to the other end is formed in the inner shell; the inner shell comprises a first section located on the throat portion of the spray pipe, second sections located on the two sides of the throat section and third sections located on the sides, away from each other, of the two second sections, the first wall thickness of the first section is smaller than the second wall thickness of the second sections, and the second wall thickness is smaller than the third wall thickness of the third sections. The reinforcing ribs are evenly distributed on the periphery of the inner shell and extend in the axial direction of the spray pipe. Each mounting block is arranged between every two adjacent reinforcing ribs, and the mounting blocks located on the two sides of each reinforcing rib are connected with the reinforcing ribs in a fastened mode; the problem of contradiction between the wall thickness and the heat conduction efficiency of a nozzle throat structure in the prior art is solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of nozzle throat, more particularly, relates to a nozzle throat structure of a supersonic high-temperature wind tunnel. BACKGROUND

[0002] The nozzle is composed of a contraction section and an expansion section, and the throat is the narrowest part of the junction of the contraction section and the expansion section. For the sonic throat, it is the key bottleneck to realize the conversion of airflow from subsonic to supersonic, and directly determines whether the hypersonic speed can be finally achieved. According to the mass conservation, the mass flow of gas flowing through the throat is constant. Since the area of the throat is the smallest, the gas density at this position is the largest. The throat section, especially the throat itself, is one of the regions with the highest heat flux density in the entire nozzle. It must use special high-temperature-resistant materials, such as copper alloy, and be equipped with an active water cooling system to prevent ablation or melting.

[0003] Under the premise of considering the heat exchange efficiency and controlling the temperature difference between the gas side and the liquid side within a reasonable range, the wall thickness of the throat section is controlled at 5mm, which is a relatively ideal thickness. However, the inventors of the present application found in research that a larger throat size leads to instability. Under the premise of not damaging the thermal conductivity coefficient of TCr1-0.15, it is a big problem to ensure the safety of the structure. Therefore, for the test conditions with high heat flux density and high temperature, how to reduce the test operation risk is also an important research direction. SUMMARY

[0004] The purpose of the present application is to solve the contradiction between the wall thickness and the heat conduction efficiency of the nozzle throat structure in the prior art by providing a nozzle throat structure of a supersonic high-temperature wind tunnel.

[0005] In order to achieve the above-mentioned purpose, the present application provides a nozzle throat structure of a supersonic high-temperature wind tunnel, comprising: an inner shell, the inside of the inner shell forms a nozzle which is first tapered and then expanded from one end to the other end, the inner shell includes a first section at the throat of the nozzle, a second section on both sides of the throat section, and a third section on the sides of the two second sections away from each other, the first wall thickness of the first section is smaller than the second wall thickness of the second section, and the second wall thickness is smaller than the third wall thickness of the third section; a plurality of reinforcing ribs, the plurality of reinforcing ribs are uniformly distributed on the outer periphery of the inner shell and extend in the axial direction of the nozzle; a plurality of mounting blocks, each mounting block is arranged between two adjacent reinforcing ribs, and the mounting blocks on both sides of each reinforcing rib are tightly connected with the reinforcing rib.

[0006] Optionally, a plurality of partition strips are arranged between adjacent reinforcing ribs and connected with the inner shell and the mounting blocks, and a first cooling channel extending along the axis of the nozzle is formed between adjacent partition strips, and a second cooling channel extending along the axis of the nozzle is formed between the partition strips on both sides of the reinforcing ribs and the reinforcing ribs.

[0007] Optionally, the partition strips comprise first, second and third portions respectively outside the first, second and third segments, and the first, second and third portions have a protruding thickness outside the inner shell matched with the wall thickness of the first, second and third segments, so that the cross-sectional dimension of the first cooling channel in the axial direction is the same, and the cross-sectional dimension of the second cooling channel in the axial direction is the same.

[0008] Optionally, the reinforcing ribs and the partition strips are integrally formed on the outer surface of the inner shell.

[0009] Optionally, the wall thickness of the first segment is 3-7mm, the wall thickness of the second segment is 8-15mm, and the wall thickness of the third segment is 16-20mm.

[0010] Optionally, a plurality of mounting blocks are connected with a plurality of reinforcing ribs to form a cylindrical structure, and the mounting blocks are provided with mounting grooves in which fasteners are mounted.

[0011] Optionally, the outer side of the reinforcing rib is provided with a clamping plate between two mounting blocks.

[0012] Optionally, the two ends of the inner shell are respectively provided with annular wings, and a gap is formed between the two ends of the mounting block and the wings.

[0013] Optionally, the width of the first cooling channel and the second cooling channel is not less than 6mm.

[0014] Optionally, the material of the inner shell is TCr1-0.15, and the material of the mounting block is S30408.

[0015] The present application provides a nozzle throat structure of a supersonic high-temperature wind tunnel, which has the beneficial effects that: the inner shell of the nozzle throat structure of the supersonic high-temperature wind tunnel adopts a stepped wall thickness, the wall thickness of the first section forming the throat is the thinnest, the heat exchange is avoided from being affected by the excessively large wall thickness of the throat, the wall thickness of the second section and the third section outwardly on both sides of the first section is steppedly thickened, the ability of resisting external pressure and instability is improved by increasing the wall thickness at the position with relatively not high temperature, meanwhile, a plurality of reinforcing ribs are arranged on the outer periphery of the outer shell, the two ends of the mounting block between the adjacent reinforcing ribs are fastened and connected with the reinforcing ribs, the structure of such fastening type can further strengthen the structure of the nozzle throat structure of the supersonic high-temperature wind tunnel, and the instability is avoided.

[0016] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0017] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which like reference characters refer to like parts throughout the several views.

[0018] Figure 1 An outer shape structure schematic diagram of a nozzle throat structure of a supersonic high-temperature wind tunnel according to one embodiment of the present application is shown.

[0019] Figure 2 A structure schematic diagram of an inner shell of a nozzle throat structure of a supersonic high-temperature wind tunnel according to one embodiment of the present application is shown.

[0020] Figure 3 An A-direction cross-sectional structure schematic diagram of Figure 1 is shown.

[0021] Figure 4 An axial cross-sectional structure schematic diagram of a nozzle throat structure of a supersonic high-temperature wind tunnel according to one embodiment of the present application is shown.

[0022] Explanation of reference signs: 1, inner shell; 2, reinforcing rib; 3, mounting block; 4, partition strip; 5, mounting groove; 6, clamping plate; 7, wing part; 8, gap; 9, hinge hole bolt. DETAILED DESCRIPTION

[0023] Preferred embodiments of the present application will be described in more detail below. Although the following describes preferred embodiments of the present application, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present application is more thoroughly and completely conveyed to those skilled in the art, and the scope of the present application is fully conveyed to those skilled in the art.

[0024] like Figures 1 to 4 As shown, the present invention provides a nozzle throat structure for a supersonic high-temperature wind tunnel, comprising: The inner shell 1 has a nozzle that gradually narrows and then expands from one end to the other. The inner shell 1 includes a first section at the throat of the nozzle, a second section on both sides of the throat, and a third section on the side of the two second sections that are far apart from each other. The first wall thickness of the first section is less than the second wall thickness of the second section, and the second wall thickness is less than the third wall thickness of the third section. Multiple reinforcing ribs 2 are evenly distributed on the outer periphery of the inner shell 1 and extend along the axial direction of the nozzle. Multiple mounting blocks 3 are provided, each mounting block 3 is disposed between two adjacent reinforcing ribs 2, and the mounting blocks 3 on both sides of each reinforcing rib 2 are fastened to the reinforcing rib 2.

[0025] Specifically, to address the contradiction between wall thickness and thermal conductivity in the existing nozzle throat structure, and considering the extremely high heat flux density in the throat section under high Mach number and high temperature conditions, and the design challenge of not being able to simply increase wall thickness to resist external pressure instability, the inner shell 1 of the nozzle throat structure of the supersonic high-temperature wind tunnel provided by this invention adopts a stepped wall thickness. The wall thickness of the first section forming the throat is the thinnest, avoiding the impact of excessive wall thickness on heat transfer. The wall thickness of the second and third sections on both sides of the first section increases in a stepped manner. In areas where the temperature is relatively low, the increased wall thickness improves the ability to resist external pressure and instability. At the same time, multiple reinforcing ribs 2 are provided on the outer periphery of the outer shell. The two ends of the mounting blocks 3 located between adjacent reinforcing ribs 2 are tightly connected to the reinforcing ribs 2. This tight-fitting structural arrangement can further strengthen the nozzle throat structure of the supersonic high-temperature wind tunnel and prevent instability.

[0026] In this embodiment, the inner shell 1 of the nozzle throat structure of the supersonic high-temperature wind tunnel is set with a stepped wall thickness according to the heat flux density and heat exchange requirements, and four reinforcing ribs 2 extend radially from the outer periphery of the inner shell 1 and are connected to the mounting block 3 through hinged hole bolts 9; a balance is achieved between heat exchange and instability resistance, which satisfies the heat exchange requirements and can effectively resist instability, reducing the risk of burn-through during test operation.

[0027] Furthermore, such as Figure 4 As shown, the design process for the wall thickness of the inner shell 1 in this embodiment is as follows: First, taking the position of the throat of the inner shell 1 excluding the minimum diameter as the zero point, define left as negative and right as positive, [-0.270, 0.118] wall thickness not exceeding 7mm, [-0.340, 0.155] wall thickness not exceeding 8mm, [-0.382, 0.195] wall thickness not exceeding 9mm, [-0.420, 0.220] wall thickness not exceeding 10mm, [-0.440, 0.250] wall thickness not exceeding 11mm, [-0.470, 0.280] wall thickness not exceeding 12mm, [-0.486, 0.315] wall thickness not exceeding 12mm. [Wall thickness not greater than 13mm, [-0.503, 0.334] Wall thickness not greater than 14mm, [-0.516, 0.354] Wall thickness not greater than 15mm, [-0.530, 0.375] Wall thickness not greater than 16mm, [-0.550, 0.397] Wall thickness not greater than 17mm, [-0.562, 0.421] Wall thickness not greater than 18mm, [-0.575, 0.446] Wall thickness not greater than 19mm, [-0.583, 0.470] Wall thickness not greater than 20mm; then, through ANSYS Steady-state thermo-solid coupled stress-strain simulation iterations were performed on the structural strength and thermal stress. The wall thickness of the inner shell 1 was calculated as follows: the first segment, namely segment AB, has a wall thickness of 5 mm [-0.340, 0.214]; the second segment, namely segment CA, has a wall thickness of 10 mm [-0.580, -0.340] and segment BD, has a wall thickness of 10 mm [0.214, 0.463]; and the third segment, namely segments EC and DF, has a wall thickness of 16 mm.

[0028] This structure is suitable for high-temperature nozzles with a throat diameter of less than 300 mm at high Mach numbers. Hypersonic nozzles have a high heat flux density in the throat. The stepped wall thickness ensures that the gas side wall temperature of the throat does not exceed 150℃ and the water side wall temperature does not exceed 90℃. The deconstruction design ensures that the thermal conductivity of TCr1-0.15 is not less than 335W / (m.℃).

[0029] Optionally, it also includes a plurality of partition strips 4, which are distributed between adjacent reinforcing ribs 2 and connected to the inner shell 1 and the mounting block 3. A first cooling channel extending axially along the nozzle is formed between adjacent partition strips 4, and a second cooling channel extending axially along the nozzle is formed between the partition strips 4 on both sides of the reinforcing rib 2 and the reinforcing rib 2.

[0030] Specifically, the coolant passages on the outer side of the inner shell 1 are formed by multiple partition strips 4 and reinforcing ribs 2 in conjunction with mounting blocks 3, and all the first cooling passages and all the second cooling passages are the same.

[0031] In this embodiment, the outer surface of the partition strip 4 on the outer side of the inner shell 1 and the inner surface of the mounting block 3 are machined according to the same profile curve to ensure that after the four mounting blocks 3 are clamped and fastened to the reinforcing rib 2, the gap 8 between the partition strip 4 and the mounting block 3 is no greater than 0.1mm.

[0032] Optionally, the partition strip 4 includes a first part, a second part, and a third part located outside the first section, the second section, and the third section, respectively. The thickness of the protrusions of the first part, the second part, and the third part on the outside of the inner shell 1 is matched with the wall thickness of the first section, the second section, and the third section, so that the cross-sectional dimensions of the first cooling channel along the axial direction are the same and the cross-sectional dimensions of the second cooling channel along the axial direction are the same.

[0033] Specifically, the first, second, and third parts of the partition strip 4 correspond to the first, second, and third sections of the inner shell 1, respectively. The wall thickness steps of the first, second, and third sections of the inner shell 1 are located on the outer side of the inner shell 1, and their inner sides form smooth nozzle walls. The inner walls of the first, second, and third parts are set in a stepped shape and cooperate with the outer sides of the first, second, and third sections, respectively, so that the cross-sectional area of ​​each first cooling channel and each second cooling channel along the axial direction is consistent, ensuring the cooling effect.

[0034] Optionally, the reinforcing rib 2 and the partition strip 4 are integrally formed on the outer surface of the inner shell 1.

[0035] Specifically, the inner shell 1 with the partition strip 4 and the reinforcing rib 2 can be made of a forging made of a high-temperature resistant and high-thermal-conductivity material.

[0036] Optionally, the wall thickness of the first segment is 3-7 mm, the wall thickness of the second segment is 8-15 mm, and the wall thickness of the third segment is 16-20 mm.

[0037] In this embodiment, the wall thickness of the first segment is 5mm, the wall thickness of the second segment is 10mm, and the wall thickness of the third segment is 16mm.

[0038] Optionally, multiple mounting blocks 3 are connected with multiple reinforcing ribs 2 to form a cylindrical structure. The mounting blocks 3 are provided with mounting grooves 5, and fasteners are installed in the mounting grooves 5.

[0039] Specifically, the mounting block 3 has a fan-shaped cross section that can form a cylindrical structure, and the mounting groove 5 facilitates the insertion and tightening of fasteners.

[0040] Optionally, a clamping plate 6 is provided on the outer side of the reinforcing rib 2, and the clamping plate 6 is located between the two mounting blocks 3.

[0041] Specifically, the clamping plate 6 is held by two mounting blocks 3, and the thickness of the clamping plate 6 matches the thickness of the reinforcing rib 2.

[0042] In this embodiment, the fastener includes a reamed hole bolt 9, and four mounting blocks 3 are connected by the reamed hole bolt 9. After the bolt is tightened, the inner shell 1 and the four mounting blocks 3 form a whole. The gap in the middle is sealed by the clamping plate 6. The bolt preload ensures that the mounting blocks 3 hold the reinforcing rib 2 tightly.

[0043] Optionally, the inner shell 1 is provided with annular wings 7 at both ends, and a gap 8 is formed between the two ends of the mounting block 3 and the wings 7.

[0044] Specifically, the gap 8 between the two ends of the mounting block 3 and the wing 7 located at both ends of the inner housing 1 forms a coolant distribution area, through which coolant can enter each first cooling channel and each second cooling channel.

[0045] Optionally, the width of the first cooling channel and the second cooling channel is not less than 6 mm.

[0046] In this embodiment, the cavity between the inner shell 1 and the mounting block 3 is pressure-bearing at 3.75MPa. There are 48 circumferentially distributed partition strips 4. The minimum distance between adjacent partition strips 4 and between partition strips 4 and reinforcing ribs 2 is 6mm. The cooling water flow rate is controlled to be greater than 14m / s at the throat, which meets the operating conditions of safe operation of the jacket cooling water pressure of 3.75MPa.

[0047] Optionally, the material of the inner shell 1 is TCr1-0.15, and the material of the mounting block 3 is S30408.

[0048] In this embodiment, the clamping plate 6 is made of the same material as the mounting block 3.

[0049] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A structure of a throat of a nozzle of a hypersonic hot wind tunnel, characterized by, The application relates to an inner shell, which is internally formed into a nozzle gradually tapered at one end and gradually expanded at the other end, and comprises a first section at the throat of the nozzle, second sections on both sides of the throat section and third sections on the sides of the two second sections away from each other, wherein the first wall thickness of the first section is smaller than the second wall thickness of the second section, and the second wall thickness is smaller than the third wall thickness of the third section. A plurality of reinforcing ribs are uniformly distributed on the outer periphery of the inner shell and extend in the axial direction of the nozzle. A plurality of mounting blocks are arranged between two adjacent reinforcing ribs, and the mounting blocks on both sides of each reinforcing rib are fastened to the reinforcing rib. A plurality of partition strips are arranged between adjacent reinforcing ribs and connected to the inner shell and the mounting blocks, and first cooling channels extending in the axial direction of the nozzle are formed between adjacent partition strips, and second cooling channels extending in the axial direction of the nozzle are formed between the partition strips on both sides of the reinforcing rib and the reinforcing rib.

2. The structure of the throat of the nozzle of the supersonic high-temperature wind tunnel according to claim 1, characterized in that, The partition strips comprise first, second and third parts on the outer sides of the first, second and third sections respectively, and the protruding thicknesses of the first, second and third parts on the outer side of the inner shell are matched with the wall thicknesses of the first, second and third sections so that the cross-sectional dimensions of the first cooling channels in the axial direction are the same, and the cross-sectional dimensions of the second cooling channels in the axial direction are the same.

3. The structure of the throat of the nozzle of the supersonic high-temperature wind tunnel according to claim 2, characterized in that, The reinforcing ribs and the partition strips are integrally formed on the outer surface of the inner shell.

4. The structure of the throat of the nozzle of the supersonic high-temperature wind tunnel according to claim 2, characterized in that, The wall thickness of the first section is 3-7 mm, the wall thickness of the second section is 8-15 mm, and the wall thickness of the third section is 16-20 mm.

5. The structure of the throat of the nozzle of the supersonic high-temperature wind tunnel according to claim 1, characterized in that, The mounting blocks are connected to the reinforcing ribs to form a cylindrical structure, and the mounting blocks are provided with mounting grooves in which fasteners are arranged.

6. The structure of the throat of the nozzle of the supersonic high-temperature wind tunnel according to claim 1, characterized in that, The outer side of the reinforcing rib is provided with a clamping plate between the two mounting blocks.

7. The structure of the throat of the nozzle of the supersonic high-temperature wind tunnel according to claim 1, characterized in that, The two ends of the inner shell are respectively provided with annular wings, and gaps are formed between the two ends of the mounting blocks and the wings.

8. The structure of the throat of the nozzle of the supersonic high-temperature wind tunnel according to claim 1, characterized in that, The widths of the first cooling channels and the second cooling channels are not less than 6 mm.

9. The structure of the throat of the nozzle of the supersonic high-temperature wind tunnel according to claim 2, characterized in that, The material of the inner shell is TCr1-0.15, and the material of the mounting blocks is S30408.

10. The structure of the throat of the nozzle of the supersonic high-temperature wind tunnel according to claim 6, characterized in that, ​

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