A distortion generator with adjustable stable dynamic index, component and flow field experimental device

Abstract

The present invention provides a distortion generator, component, and flow field experimental device with adjustable steady and dynamic indexes, relating to the field of flow field testing, to solve the technical problem that the distortion generator cannot effectively adjust the ratio of steady and dynamic distortion indexes. The distortion generator includes a first pipe, a second pipe, and a plurality of nozzles arranged outside the first pipe and the second pipe; the first pipe and the second pipe have flow channels with the same inner diameter; the end of the first pipe has an annular first flange portion protruding outward, and the end of the second pipe has an annular second flange portion protruding outward, the end of the first flange portion has a tapered portion, and the second flange portion has a cavity for accommodating the tapered portion, the tapered portion is coordinated with the cavity, and the surface of the tapered portion is spaced apart from the inner wall surface of the cavity to form a slit; the distortion generator also includes a plurality of spacers, each spacer is used to divide the slit into a plurality of air inlets evenly distributed along the circumference of the distortion generator, and each air inlet is connected to a corresponding nozzle.

Description

Technical Field

[0001] The present invention relates to the field of flow field testing, and in particular to a distortion generator with adjustable steady-state index, a component and a flow field experimental device. Background Art

[0002] With the continuous development of aircraft, the intake distortion of aircraft engines is significantly affected by factors such as high-maneuverability fighter jets, the use of S-shaped inlets for stealth design, and missile trails. Total pressure intake distortion can cause uneven force on the blades, a major factor in blade fatigue. In severe cases, it can lead to engine surge, blade fracture, and even mid-flight shutdown accidents.

[0003] Total pressure inlet distortion is primarily categorized as steady-state and dynamic. Both steady-state and dynamic total pressure distortion can impact aircraft engine performance and stability margins. Using a distortion simulator to simulate steady-state and dynamic total pressure distortion at the engine inlet is an efficient and safe method. However, existing total pressure distortion simulators are limited by the near-1:1 ratio of the steady-state and dynamic total pressure distortion exponents they produce, making it difficult to accurately simulate actual engine inlet total pressure distortion. Summary of the Invention

[0004] The object of the present invention is to provide a distortion generator with adjustable steady and dynamic indexes, so as to solve the technical problem that the intake total pressure distortion generator cannot effectively adjust the ratio of the steady and dynamic distortion indexes.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The embodiment of the present invention provides a distortion generator with adjustable steady-state index, which is used to adjust the spatial distribution of high- and low-pressure fluids. The distortion generator includes a first pipe, a second pipe, and a plurality of nozzles provided outside the first pipe and / or the second pipe.

[0007] The first pipe and the second pipe have flow channels with the same inner diameter;

[0008] The end of the first pipe has a first flange portion protruding outward, and the end of the second pipe has a second annular flange portion protruding outward. The end of the first flange portion has a tapered portion, and the second flange portion has a cavity for accommodating the tapered portion. The tapered portion is aligned with the cavity, and a surface of the tapered portion is spaced apart from an inner wall surface of the cavity to form a slit.

[0009] The distortion generator further includes a plurality of spacers, each of which is used to divide the slit into a plurality of air inlets evenly distributed along the circumferential direction, and each of the air inlets is connected to a corresponding nozzle.

[0010] According to at least one embodiment of the present invention, each of the spacers is a protrusion uniformly provided on the surface of the tapered portion, the protrusion having an end surface facing away from the surface of the tapered portion, the end surface being in contact with the inner wall surface of the cavity, or

[0011] Each of the spacers is a protrusion uniformly arranged on the inner wall surface of the cavity. The protrusion has an end surface facing away from the inner wall surface of the cavity, and the end surface is in contact with the surface of the tapered portion.

[0012] According to at least one embodiment of the present invention, the width of the air inlet is 0.25% to 0.85% of the diameter of the first pipe, and the width direction of the air inlet is: the distribution direction from the surface of the tapered portion to the inner wall surface of the cavity;

[0013] The number of the air inlets is 8 to 32.

[0014] According to at least one embodiment of the present invention, the cone angle of the cone portion is 60° to 120°, and the jet surface of the nozzle is coplanar with the surface of the cone portion.

[0015] According to at least one embodiment of the present invention, a fixing plate is further provided at the end of the nozzle, and the first flange portion and the second flange portion are respectively connected to the fixing plate;

[0016] The fixing plate has a first plate section and a second plate section arranged in an L-shape with the first plate section. The end surface of the first plate section facing away from the nozzle is arranged on the outer circumferential surfaces of the first flange portion and the second flange portion. The end surface of the second flange portion facing away from the first flange portion is also provided with a groove near the outer circumferential surface. The groove cooperates with the second plate section for axial positioning of the nozzle.

[0017] According to at least one embodiment of the present invention, a first positioning hole is provided on an end surface of the spacer portion of the first flange portion facing away from the first flange portion, and a second positioning hole is provided on an end surface of the second flange portion facing away from the first flange portion, wherein the first positioning hole and the second positioning hole cooperate to locate the circumferential positions of the first pipe and the second pipe;

[0018] A third positioning hole is provided on the outer circumferential surface of the second flange portion, and the first plate section of the fixing plate has a fourth positioning hole. The third positioning hole cooperates with the fourth positioning hole to circumferentially position the nozzle.

[0019] According to at least one embodiment of the present invention, the end portion of the first plate segment facing away from the second plate segment is welded to the first flange portion;

[0020] An end surface of the second plate segment facing away from the first plate segment is welded to a bottom surface of the groove.

[0021] According to at least one embodiment of the present invention, the distortion generator further includes a controller, which is communicatively connected to the valves of each of the nozzles, and is used to control the opening and closing of each of the nozzles and the jet velocity.

[0022] Compared with the prior art, the distortion generator of the present invention has the following advantages:

[0023] The present invention provides a distortion generator with an adjustable steady-state index. A first flange portion protruding outward is provided at the end of a first pipe, and a second annular flange portion protruding outward is provided at the end of a second pipe. The first flange portion has a tapered portion at its end, which cooperates with the cavity of the second flange portion. The surface of the tapered portion is parallel to the inner wall of the cavity and spaced apart to form a slit through which the jet generated by the nozzle passes. Multiple spacers are provided within the slit, forming multiple air inlets evenly distributed along the circumference of the distortion generator, each of which is connected to an independent nozzle. Because the air inlets are formed by the tapered portion, cavity, and spacers, the jets from the air inlets are inclined at a certain angle to the central axis of the flow channel. The air inlet jets located in the high-pressure area can reduce the total pressure in the high-pressure area, thereby changing the distribution of high and low pressure regions in the flow field.

[0024] Compared to using a single pipe to create an air inlet and then connecting the nozzle to the air inlet, which requires welding to ensure airtightness, and thermal deformation at the weld point can affect the machining accuracy of the jet slit, the present invention locates the connection between the nozzle and the two pipes on the first and second flanges, away from the air inlet and closer to the inner wall of the flow channel. This ensures that thermal deformation caused by welding does not affect the machining accuracy of the jet slit. At the same time, the length of the air inlet is extended, improving the accuracy of the jet direction.

[0025] Another object of the present invention is to provide a distortion generator assembly, comprising a high- and low-pressure fluid generator and the above-mentioned distortion generator, wherein the distortion generator is arranged after the high- and low-pressure fluid generator along the fluid flow direction, and the distance between the distortion generator and the high- and low-pressure fluid generator is 0.5 to 1.5 times the diameter of the flow channel;

[0026] The controller is in communication with the high and low pressure fluid generators, and is used to adjust the steady-state dynamic distortion index in the flow channel.

[0027] Compared with the prior art, the advantages of the distortion generator assembly described in the present invention are the same as those of the above-mentioned distortion generator, which will not be repeated here.

[0028] Another object of the present invention is to provide a flow field experimental device, comprising a distortion generator assembly and a fan, wherein the fan is connected to the flow channel of the distortion generator assembly through a pipeline.

[0029] Compared with the prior art, the advantages of the flow field experimental device described in the present invention are the same as those of the above-mentioned distortion generator, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings illustrate exemplary embodiments of the present invention and together with the description serve to explain the principles of the present invention. These drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this specification.

[0031] Figure 1 Schematic diagram of the three-dimensional structure of a distortion generator according to an embodiment of the present invention.

[0032] Figure 2 yes Figure 1 Schematic diagram of the front view structure.

[0033] Figure 3 yes Figure 2 Schematic diagram of the cross-sectional structure.

[0034] Figure 4 Schematic diagram of the three-dimensional structure of the first pipeline according to an embodiment of the present invention.

[0035] Figure 5 yes Figure 4 Schematic diagram of the front view structure.

[0036] Figure 6 is a schematic diagram of the three-dimensional structure of the second pipeline according to an embodiment of the present invention.

[0037] Figure 7 yes Figure 6 Schematic diagram of the cross-sectional structure.

[0038] Figure 8 yes Figure 7 Schematic diagram of the enlarged structure of part A.

[0039] Figure 9 FIG. 4 is a schematic diagram of a three-dimensional structure of a nozzle according to an embodiment of the present invention.

[0040] Figure 10 The utility model is a plug-in plate type high and low pressure fluid generator in the prior art.

[0041] Figure numerals: 1, first pipe; 11, first flange portion; 111, tapered portion; 112, spacer portion; 2, second pipe; 21, second flange portion; 211, inner wall surface; 212, groove; 3, nozzle; 4, air inlet; 5, fixing plate; 51, first plate section; 52, second plate section; 61, first positioning hole; 62, second positioning hole; 63, third positioning hole; 64, fourth positioning hole; 80, plug-in plate; 90, pipeline. DETAILED DESCRIPTION

[0042] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It will be understood that the specific embodiments described herein are intended only to explain the relevant content and are not intended to limit the present invention. It should also be noted that, for ease of description, only portions relevant to the present invention are shown in the accompanying drawings.

[0043] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0044] See also Figure 10 As shown, most total pressure distortion simulators are plug-in plate-type, available in single or dual-plate configurations. The intensity of the distortion is adjusted by adjusting the number of plug-in plates 80 and the depth of insertion into the pipe 90. This simple and reliable adjustment method allows for simple and reliable adjustment. Inserting a plug-in plate into the inlet duct blocks the normal flow of air, creating a low-speed recirculation zone behind the plug-in plate. This creates high and low pressure regions in the measured section, resulting in strong total pressure distortion. This plug-in plate-type total pressure distortion simulator can also generate both steady and dynamic total pressure distortion.

[0045] To more accurately simulate the total pressure inlet distortion experienced by actual engines, a distortion simulator with adjustable steady-state total pressure distortion index and its ratio is needed. However, the aforementioned plug-in type total pressure distortion simulator produces a steady-state total pressure distortion index ratio close to 1:1, making it impossible to arbitrarily adjust the ratio of the steady-state total pressure distortion index and thus making it difficult to accurately simulate actual engine inlet total pressure distortion.

[0046] Based on the limitations of the above-mentioned existing technologies, the present invention provides a distortion generator that can adjust the steady-dynamic total pressure distortion index and its ratio, and adjusts the distribution of high and low pressure fluids in space through jets, thereby adjusting the steady-dynamic total pressure distortion index and its ratio.

[0047] See also Figures 1 to 8As shown, according to an exemplary embodiment of the present invention, a distortion generator with an adjustable steady-state index is provided, comprising a first pipe 1, a second pipe 2, and a plurality of nozzles 3 arranged outside the first pipe 1 and / or the second pipe 2; the first pipe 1 and the second pipe 2 have flow channels with the same inner diameter; the end of the first pipe 1 has a first flange portion 11 protruding outward, the end of the second pipe 2 has an annular second flange portion 21 protruding outward, the end of the first flange portion 11 has a tapered portion 111, the second flange portion 21 has a cavity for accommodating the tapered portion 111, the tapered portion 111 is coordinated with the cavity, and the surface of the tapered portion 111 is parallel to the inner wall surface 211 of the cavity and spaced apart to form a slit; the distortion generator further comprises a plurality of spacers 112, each spacer 112 being used to divide the slit into a plurality of air inlets 4 evenly distributed along the circumference of the distortion generator, and each air inlet 4 is connected to a corresponding nozzle 3.

[0048] In actual use, nozzle 3 is connected to a compressed air tank, continuously supplying compressed air to meet the jet flow requirements. By adjusting the on / off flow and jet velocity of each nozzle 3, selecting the appropriate position of the air inlet 4 for jet flow, and controlling the jet velocity, the jet flow in the high-pressure area can effectively reduce the total pressure in the high-pressure area, change the distribution of high and low pressure areas in the flow field, and reduce steady-state total pressure distortion. Numerical simulation results show that the addition of the jet has little effect on the dynamic total pressure distortion index, but can significantly affect the steady-state total pressure distortion, thereby changing the proportion of steady-state dynamic total pressure distortion.

[0049] In some embodiments, the flow channel is designed as two sections, a first pipe 1 and a second pipe 2, both having the same inner diameter, thus forming a complete flow channel. This is primarily for the purpose of machining the air inlet 4. Using a connection method in which the air inlet is opened on one pipe and then the nozzle is welded, thermal deformation occurs at the weld point, affecting the machining dimensions of the air inlet and making it impossible to control the steady-state total pressure distortion ratio. The embodiments of the present invention employ a flange at the junction of the two pipes, which not only lengthens the air inlet and improves the accuracy of the jet direction, but also ensures that the size of the air inlet 4 near the inner wall is maintained when the nozzle is welded to the flange. Exemplarily, a tapered portion 111 is provided at the end of the first flange portion 11 of the first pipe 1, and a cavity for accommodating the tapered portion 111 is provided at the second flange portion 21 of the second pipe 2. The surface of the tapered portion 111 is parallel to the inner wall surface 211 of the cavity and spaced apart to form a slit, and a plurality of spacers 112 are provided therein to divide the slit into a plurality of air inlets 4 uniformly distributed along the circumference of the distortion generator, so that the jet opening and closing and the jet velocity of each air inlet 4 can be independently controlled, thereby achieving the purpose of adjusting the distribution of high and low pressure areas in the flow channel.

[0050] For example, see Figure 5As shown, each spacer 112 is a protrusion uniformly provided on the surface of the tapered portion 111, with the protrusion having an end surface facing away from the surface of the tapered portion 111. The end surface of the spacer 112 is in contact with the inner wall surface 211 of the cavity. The protrusions of each spacer 112 are of the same height, so that the width of the formed air inlet 4 is uniform along the radial direction. It is understandable that the above-mentioned each spacer 112 can also be a protrusion uniformly provided on the inner wall surface 211 of the cavity, with the protrusion having an end surface facing away from the inner wall surface 211 of the cavity, and the end surface of the protrusion is in contact with the surface of the tapered portion 111, thereby forming each air inlet 4. The tapered portion 111 and the spacer 112 are integrally formed, which is easier to process and form than when the spacer 112 is provided on the inner wall surface 211 of the cavity.

[0051] In some embodiments, the width of the air inlet 4 is 0.25% to 0.85% of the diameter of the first conduit 1, optionally 0.5% to 0.6%. The width of the air inlet 4 is measured from the surface of the tapered portion 111 to the inner wall 211 of the cavity. For example, for an air inlet with a diameter of 905 mm, the jet slit is set to 2.5 mm to 7.5 mm, optionally 5 mm. The number of air inlets 4 is primarily determined by the diameter of the air inlet. A larger air inlet diameter and a longer wall circumference allow for more placement of air inlets 4. The required jet control precision increases with the number of air inlets 4, resulting in higher flow field accuracy. For example, the number of air inlets 4 is 8 to 32, optionally 16. The arc length of the air inlet 4 is determined by the number of air inlets 4 and is proportional to: inlet circumference / number of air inlets. The width of the spacer 112 also needs to be considered.

[0052] Considering the influence of the jet direction on the distribution of high and low pressure areas in the flow field, please refer to Figure 3 As shown, the air inlet 4 forms an angle α with the axis of the flow channel and is opposite to the incoming flow direction. The jet direction is exemplarily angled α between 30° and 60°, and optionally 45°. From another perspective, the cone angle of the tapered portion 111 is between 60° and 120°. To provide a more precise jet direction, the jet surface of the nozzle 3 should also be coplanar with the surface of the tapered portion 111.

[0053] In order to fix the nozzle 3 on the pipe and connect it to the air inlet 4, in some embodiments, refer to Figures 1 to 3 、 Figures 7 to 9As shown, the nozzle 3 is further provided with a fixing plate 5 at its bottom. The fixing plate 5 is disposed on the first flange portion 11 and the second flange portion 21. Specifically, the fixing plate 5 comprises a first plate segment 51 and a second plate segment 52, which are arranged in an L-shape. A portion of the first plate segment 51, which faces away from the nozzle 3, is affixed to the outer circumference of the first flange portion 11, while another portion is affixed to the outer circumference of the second flange portion 21. Accordingly, a groove 212 is further provided near the outer circumference of the end face of the second flange portion 21, which faces away from the first flange portion 11. The groove 212 cooperates with the second plate segment 52 for axial positioning of the nozzle 3. The bottom surface of the second plate segment 52 is fixedly connected to the bottom surface of the groove 212, for example, by welding. The bottom surface of the first plate segment 51, which faces away from the second plate segment 52, is fixedly connected to the outer circumference of the first flange portion 11, for example, by welding.

[0054] In some embodiments, the precise positioning of the various pipes and nozzles is considered. Figures 5 to 9 As shown, a first positioning hole 61 is provided on the end surface of the spacer portion 112 of the first flange portion 11 away from the first flange portion 11, and a second positioning hole 62 is provided on the second flange portion 21 to match the corresponding first positioning hole 61. Figure 8 As shown, the second positioning hole 62 extends along the axial direction of the flow channel from below the groove 212 of the second flange portion 21 to the inner wall of the cavity. When in use, a pin is passed through the second positioning hole 62 until it reaches the first positioning hole 61 of the spacer portion 112 for positioning, so that the circumferential positions of the first pipe 1 and the second pipe 2 remain relatively fixed. Figure 6 As shown, a third positioning hole 63 is provided on the outer circumferential surface of the second flange portion 21, and a corresponding fourth positioning hole 64 is provided in the first plate segment 51 of the fixing plate 5. The fourth positioning hole 64 is a through hole that penetrates the first plate segment 51. A pin is inserted through the fourth positioning hole 64 and reaches the third positioning hole 63 in the second flange portion 21, thereby achieving circumferential positioning of the fixing plate 5, that is, circumferential positioning of the nozzle 3, and then performing a welding fixation connection. The provision of each positioning hole can precisely control the connection position between each component, thereby improving processing precision and ensuring the accuracy of test results.

[0055] In some embodiments, the above-mentioned distortion generator with adjustable steady-state index further includes a controller, which is in communication with the valves of each nozzle 3 and is configured to control the opening and closing of each nozzle 3 and the jet velocity. By controlling the opening and closing of the corresponding nozzles and the corresponding jet velocity, the controller controls the position and velocity of the air jet from the air inlet 4 ejected into the pipe, thereby changing the distribution of high and low pressure areas in the flow field and simulating intake distortion conditions with different steady-state total pressure distortion ratios.

[0056] In some embodiments, the nozzle 3 primarily serves to connect to the high-pressure air duct. The nozzle 3 has a bell-shaped design for connecting the air inlet and the high-pressure air duct. While the high-pressure air duct is typically circular, it can also have other shapes, and the air inlet 4 is slit-shaped. Therefore, the bell-shaped design only needs to transition the high-pressure air duct to the shape of the air inlet 4, and ensure that the jet plane of the bell-shaped design aligns with the jet plane of the air inlet 4.

[0057] According to another object of the present invention, a distortion generator assembly is provided, comprising a high- and low-pressure fluid generator and the aforementioned distortion generator. The distortion generator is positioned downstream of the high- and low-pressure fluid generator along the fluid flow direction, with the spacing between the distortion generator and the high- and low-pressure fluid generator being 0.5 to 1.5 times the flow channel diameter. A controller is communicatively coupled to the high- and low-pressure fluid generator and configured to adjust the steady-state dynamic distortion index in the flow channel. The high- and low-pressure fluid generator can be a single- or dual-plate distortion simulator, with the plates being of a crescent-shaped or slat-shaped configuration. It is understood that the distortion generator of the present invention can adjust the high- and low-pressure region distribution of any high- and low-pressure fluid simulation device.

[0058] For example, using a plug-in plate distortion simulator as an example, the distortion generator of an embodiment of the present invention is positioned behind the plug-in plate distortion simulator, with the axial distance between the two typically being 0.5 to 1.5 times the flow channel diameter, and optionally, 1 times the flow channel diameter. A controller is also in communication with the plug-in plate distortion simulator. Based on the distribution of high and low pressure regions in the flow field generated by the plug-in plate height of the plug-in plate distortion simulator, the controller controls the jet position and velocity of the distortion generator of the present invention, thereby simulating intake distortion conditions with varying steady-state and dynamic total pressure distortion ratios.

[0059] According to another object of the present invention, a flow field experimental apparatus is provided, comprising the aforementioned distortion generator assembly and a fan, the fan being connected to the flow channel of the distortion generator assembly via a pipeline. The fan is positioned behind the flow channel, and the motor speed is varied by adjusting the output power of the frequency converter, thereby varying the rotational frequency of the fan, thereby adjusting the Mach number of the incoming flow during the test.

[0060] The numerical simulation results of the above-mentioned flow field experimental device show that the addition of the jet has little effect on the dynamic total pressure distortion index, but can significantly affect the steady-state total pressure distortion. Therefore, the flow field experimental device of the embodiment of the present invention can achieve the adjustment of the ratio of the steady and dynamic distortion indices to a certain extent.

[0061] In the description of this specification, the description with reference to the terms "one embodiment / method", "some embodiments / methods", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment / method or example are included in at least one embodiment / method or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment / method or example. Moreover, the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more embodiments / methods or examples. In addition, those skilled in the art may combine and combine different embodiments / methods or examples described in this specification and the features of different embodiments / methods or examples, unless they are contradictory.

[0062] Furthermore, 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 the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0063] It should be understood by those skilled in the art that the above embodiments are merely for the purpose of illustrating the present invention clearly, and are not intended to limit the scope of the present invention. For those skilled in the art, other changes or modifications may be made based on the above disclosure, and such changes or modifications are still within the scope of the present invention.

Claims

1. A distortion generator with adjustable stable dynamic index, characterized in that: Used to adjust the distribution of high and low pressure fluids in space, the distortion generator includes a first pipe, a second pipe and a plurality of nozzles provided outside the first pipe and / or the second pipe; The first pipe and the second pipe have flow channels with the same inner diameter; The end of the first pipe has an outwardly protruding annular first flange portion, and the end of the second pipe has an outwardly protruding annular second flange portion, the end of the first flange portion has a tapered portion, and the second flange portion has a cavity for accommodating the tapered portion, the tapered portion is coordinated with the cavity, and the surface of the tapered portion is spaced apart from the inner wall surface of the cavity to form a slit; The distortion generator further includes a plurality of spacers, each of which is used to divide the slit into a plurality of air inlets evenly distributed along the circumference of the distortion generator, and each of the air inlets is connected to a corresponding nozzle.

2. The distortion generator according to claim 1, characterized in that Each of the spacers is a protrusion uniformly arranged on the surface of the tapered portion, and the protrusion has an end surface away from the surface of the tapered portion, and the end surface is in contact with the inner wall surface of the cavity, or Each of the spacers is a protrusion uniformly arranged on the inner wall surface of the cavity. The protrusion has an end surface facing away from the inner wall surface of the cavity, and the end surface is in contact with the surface of the tapered portion.

3. The distortion generator according to claim 1, characterized in that The width of the air inlet is 0.25% to 0.85% of the diameter of the first pipe, and the width direction of the air inlet is: the distribution direction from the surface of the tapered portion to the inner wall surface of the cavity; The number of the air inlets is 8 to 32.

4. The distortion generator according to claim 1, characterized in that The cone angle of the cone portion is 60° to 120°, and the jet surface of the nozzle is coplanar with the surface of the cone portion.

5. The distortion generator according to any one of claims 1 to 4, characterized in that: The end of the nozzle is further provided with a fixing plate, and the first flange portion and the second flange portion are respectively connected to the fixing plate; The fixing plate has a first plate section and a second plate section arranged in an L-shape with the first plate section. The end surface of the first plate section facing away from the nozzle is arranged on the outer circumferential surfaces of the first flange portion and the second flange portion. The end surface of the second flange portion facing away from the first flange portion is also provided with a groove near the outer circumferential surface. The groove cooperates with the second plate section for axial positioning of the nozzle.

6. The distortion generator according to claim 5, characterized in that A first positioning hole is provided on the end surface of the spacer portion of the first flange portion facing away from the first flange portion, and a second positioning hole is provided on the second flange portion to coordinate with the corresponding first positioning hole, for circumferential positioning of the first pipe and the second pipe; A third positioning hole is provided on the outer circumferential surface of the second flange portion, and the first plate section of the fixing plate has a fourth positioning hole. The third positioning hole cooperates with the fourth positioning hole to circumferentially position the nozzle.

7. The distortion generator according to claim 5, characterized in that The end of the first plate segment facing away from the second plate segment is welded to the first flange portion; An end surface of the second plate segment facing away from the first plate segment is welded to a bottom surface of the groove.

8. The distortion generator according to claim 5, characterized in that The distortion generator further includes a controller, which is in communication with the valves of each nozzle and is used to control the opening and closing of each nozzle and the jet velocity.

9. A distortion generator assembly, characterized in that: The invention comprises a high- and low-pressure fluid generator and the distortion generator according to any one of claims 1 to 8, wherein the distortion generator is arranged after the high- and low-pressure fluid generator along the fluid flow direction, and the distance between the distortion generator and the high- and low-pressure fluid generator is 0.5 to 1.5 times the diameter of the flow channel; The controller is in communication with the high and low pressure fluid generators, and is used to adjust the steady-state dynamic distortion index in the flow channel.

10. A flow field experimental device, characterized in that: It comprises the distortion generator assembly according to claim 9 and a fan, wherein the fan is connected to the flow channel of the distortion generator assembly through a pipeline.

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