Wind tunnel type measuring device specially applied to fiber filament resistance measurement

Abstract

The invention provides a wind tunnel type measuring device specially applied to fiber filament resistance measurement. The wind tunnel type measuring device is used for achieving wind resistance measurement of fiber filaments under different conditions. Relates to the technical field of fiber filament resistance measurement. Comprising a vertical wind tunnel body, an ejector and a high-precision tension meter. The vertical wind tunnel body comprises an acceleration section, a stable section and a diffusion section. The accelerating section is connected with the diffusion section through the stabilizing section, and the other end of the diffusion section is connected with the ejector. The acceleration section is used for increasing the low airflow speed at the inlet to supersonic speed or hypersonic speed, and the airflow is transmitted to the ejector through the stable section and the diffusion section in sequence; the ejector is used for ejecting low-speed low-energy flow in the wind tunnel body through high-speed high-energy flow, so that the high-speed high-energy flow and the low-speed low-energy flow are mixed to form a stable wind field, and the stable wind field passes through the diffusion section and then returns to the stable section. The stable section is used as an experiment section for placing a fiber filament, and the high-precision tension meter is connected with the fiber filament. The device is suitable for measuring the wind resistance of the fiber filaments under different conditions.

Description

Technical Field

[0001] The invention relates to the technical field of fiber filament resistance measurement, and in particular to a wind tunnel type measurement device specially used for fiber filament resistance measurement. Background Art

[0002] By measuring the resistance of fiber filaments, their tensile strength and elastic modulus can be evaluated. These parameters are crucial for designing lightweight and high-strength composite materials. At the same time, the resistance measurement of fiber filaments helps to identify the weak links of the material, thereby optimizing the material formulation and production process to ensure the reliability and durability of the composite material under extreme conditions.

[0003] In industries such as composite materials, the resistance measurement of fiber filaments is an important part of quality control. It not only ensures that the fiber products meet specific mechanical performance standards. It also helps to understand their mechanical behavior under different conditions, such as elastic modulus, fracture stress and strain, which are crucial for optimizing the strength, toughness and durability of the fiber. By measuring the resistance, it is possible to evaluate the performance of the fiber during deformation processes such as stretching, bending or torsion, thereby improving the fiber production process.

[0004] In the research and development of new materials, understanding the resistance characteristics of fibers can guide their application in the fields of bionic robots, special aviation, etc.

[0005] Therefore, it is very important to accurately measure the wind resistance of fiber filaments under different conditions. However, there is a gap in the prior art in this regard. Although the existing methods usually use microscope measurement, laser diffraction, resonance method and airflow meter method to measure fiber filaments; among them, microscope measurement method: directly observe the diameter of fiber filaments through a microscope, and then calculate its cross-sectional area and related mechanical properties. Laser diffraction method: use the principle of laser diffraction to measure the diameter of fiber filaments, which is suitable for high-precision measurement. Resonance method: indirectly calculate its cross-sectional area and Young's modulus by measuring the resonance frequency of fiber filaments. Airflow meter method: indirectly measure its linear density or diameter by using the relationship between the specific surface area of ​​fiber filaments and airflow resistance. However, the above-mentioned measurement techniques only involve direct observation or measurement of the geometric dimensions of fiber filaments, so as to obtain parameters such as diameter or cross-sectional area and then substitute them into empirical formulas for calculation, while the measurement of wind resistance of fiber filaments is still blank, especially the aerodynamic and mechanical behavior of multiple filaments in the wind field, and the theory involved is extremely complex. Therefore, there is an urgent need for a measuring device that can accurately measure the wind resistance of fiber filaments under different conditions. Summary of the invention

[0006] The purpose of the present invention is to provide a wind tunnel measuring device specially used for measuring the resistance of fiber filaments, which is used to measure the wind resistance of fiber filaments under different conditions. The measuring device proposed by the present invention can directly simulate different wind speeds and different flow field conditions, directly measure the air resistance of fiber filaments, and the data obtained is more accurate and consistent with the actual results.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] The present invention provides a wind tunnel type measuring device specially used for measuring the resistance of fiber filaments, the device comprising a vertical wind tunnel body, an ejector and a high-precision dynamometer;

[0009] The main body of the vertical wind tunnel includes an acceleration section, a stabilization section, and a diffusion section;

[0010] The acceleration section is connected to the diffusion section through the stabilization section, and the other end of the diffusion section is connected to the ejector;

[0011] The acceleration section is used to increase the low air flow velocity at the inlet to supersonic or hypersonic speed, and transmit it to the ejector through the stabilization section and the diffusion section in sequence;

[0012] The ejector is used to use the high-speed and high-energy flow to eject the low-speed and low-energy flow in the wind tunnel body, so that the high-speed and high-energy flow and the low-speed and low-energy flow are mixed to form a stable wind field, and then returned to the stable section through the diffusion section;

[0013] The stable section is used as the experimental section to place the fiber filaments, and a high-precision tensile gauge is connected to the fiber filaments.

[0014] Furthermore, a channel with a gradually decreasing cross-sectional area is used as an acceleration section;

[0015] The cross-sectional area at the entrance of the acceleration section is 750mm×750mm, the cross-sectional area at the exit is 314mm×314mm, and a 300mm square hole is also provided at the exit.

[0016] Furthermore, an interface end is provided at the front part of the stabilizing section, and the interface end has a size of 300×300 mm, which is used to connect with the square hole of the accelerating section.

[0017] Furthermore, an anemometer is provided at the right end of the stable section for measuring the wind speed in the stable section.

[0018] Furthermore, a small hollow square platform of 70×70 mm is provided in the stabilizing section for carrying fiber filaments and a high-precision dynamometer.

[0019] Furthermore, a channel with a gradually increasing cross-sectional area is used as the diffusion section.

[0020] Furthermore, 10×15 small nozzles are evenly arranged on the ejector.

[0021] Furthermore, each of the small nozzles mentioned above includes at least one high-pressure fluid inlet having a contraction design for receiving the high-pressure fluid;

[0022] at least two low-pressure fluid inlets for receiving low-pressure fluid;

[0023] A mixing chamber, used to be connected to the high-pressure fluid inlet and the low-pressure fluid inlet so as to preliminarily mix the high-pressure fluid and the low-pressure fluid;

[0024] A mixing tube connected to the mixing chamber and used to further mix the fluid;

[0025] The diffusion tube is used to be connected with the mixing tube and is used to diffuse and discharge the mixed fluid.

[0026] Furthermore, the contraction design of the high-pressure fluid inlet includes:

[0027] A constriction, where the cross-sectional area gradually decreases to accelerate the fluid flow rate;

[0028] An inlet section is connected to the contraction section and is used to receive the high-pressure fluid.

[0029] Further, the mixing chamber has at least one internal baffle for guiding the fluid flow and promoting mixing;

[0030] The diffuser has a gradually increasing cross-sectional area to reduce the fluid velocity and further mix the fluid.

[0031] The beneficial effects of the present invention are as follows:

[0032] The present invention designs a wind tunnel measuring device specially used for measuring the resistance of fiber filaments. By setting the fiber filaments in a stable section in the wind tunnel and designing the wind tunnel and the ejector, a stable wind field is generated in the stable section, thereby making the measurement more accurate and being able to simulate different wind speed conditions.

[0033] Furthermore, the present invention designs an ejector nozzle, and a plurality of ejector nozzle arrays are combined to form a larger ejector. Each ejector nozzle uses a high-speed airflow to eject a low-speed airflow, thereby achieving the purpose of generating a stable wind field inside the entire device.

[0034] Furthermore, the present invention adopts a vertical wind tunnel design to reduce the influence of gravity on the measurement of fiber filaments.

[0035] The present invention is suitable for measuring the wind resistance of fiber filaments under different conditions, so that understanding the resistance characteristics of the fiber can guide its application in the fields of bionic robots, special flights, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 is a schematic structural diagram of the wind tunnel body of the present invention;

[0038] Figure 2 It is a schematic diagram of the three-dimensional structure of the acceleration section of the present invention;

[0039] Figure 3 It is a structural schematic diagram of the acceleration section of the present invention;

[0040] Figure 4 is a schematic diagram of the three-dimensional structure of the stabilizing segment of the present invention;

[0041] Figure 5 is a schematic diagram of the internal structure of the stabilizing section of the present invention;

[0042] Figure 6 is a top view of the stabilizing section of the present invention;

[0043] Figure 7 is a front view of the diffusion section of the present invention;

[0044] Figure 8 is a side view of the diffuser section of the present invention;

[0045] Fig. 9 is a front view of the ejector of the present invention;

[0046] Fig.10 is a side view of the ejector of the present invention;

[0047] Fig.11 It is a schematic diagram of the structure of each small nozzle of the ejector of the present invention;

[0048] Fig.12 It is a structural schematic diagram of the aluminum profile support frame of the present invention;

[0049] Fig.13 It is a structural schematic diagram of the tensile meter of the present invention;

[0050] Fig.14 It is a structural schematic diagram of the anemometer of the present invention;

[0051] Fig.15 It is the wind speed parameter simulation diagram of the present invention;

[0052] Fig.16 It is an overall structural diagram of the wind tunnel type measuring device for measuring the resistance of fiber filaments according to the present invention;

[0053] Fig.17 yes Fig.16 A partial enlarged view of . DETAILED DESCRIPTION

[0054] In the following description, specific details such as specific system structures and technologies are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0055] It should be understood that when used in this specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0056] The specific embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

[0057] Implementation method 1, see Figure 1 The present embodiment is described as follows: the present embodiment provides a wind tunnel measuring device specially used for measuring the resistance of fiber filaments, and is used for accurately measuring the wind resistance of fiber filaments under different conditions.

[0058] The measuring device includes a vertical wind tunnel body, an ejector and a high-precision dynamometer;

[0059] The main body of the vertical wind tunnel includes an acceleration section, a stabilization section, and a diffusion section;

[0060] The acceleration section is connected to the diffusion section through the stabilization section, and the other end of the diffusion section is connected to the ejector;

[0061] The acceleration section is used to increase the low air flow velocity at the inlet to supersonic or hypersonic speed, and transmit it to the ejector through the stabilization section and the diffusion section in sequence;

[0062] The ejector is used to use the high-speed and high-energy flow to eject the low-speed and low-energy flow in the wind tunnel body, so that the high-speed and high-energy flow and the low-speed and low-energy flow are mixed to form a stable wind field, and then returned to the stable section through the diffusion section;

[0063] The stable section is used as the experimental section to place the fiber filaments, and a high-precision tensile gauge is connected to the fiber filaments.

[0064] In practical application, this embodiment comprises a vertical wind tunnel body, a tensile machine, an anemometer and an ejector to form a wind tunnel device for measuring the resistance of multiple fiber filaments; wherein the wind tunnel body is as follows: Figure 1 As shown, it includes an acceleration section, a stabilization section and a diffusion section; the acceleration section is connected to the diffusion section through the stabilization section, and the other end of the diffusion section is connected to the ejector; the acceleration section is used to increase the low airflow velocity at the inlet to supersonic or hypersonic, and transmit it to the ejector through the stabilization section and the diffusion section in turn; the ejector is used to use the high-speed and high-energy flow to eject the low-speed and low-energy flow in the wind tunnel body, so that the high-speed and high-energy flow and the low-speed and low-energy flow are mixed to form a stable wind field, and then returned to the stabilization section through the diffusion section; thereby achieving the purpose of generating a stable wind field inside the entire device. The wind speed range in the stabilization section is 0 to 100 m / s.

[0065] Furthermore, the main material of the device is stainless steel, and the stable section not only plays the role of generating stable airflow, but also serves as the main operating space for conducting experiments. The stable section is made of acrylic, and the transparent material facilitates observation of the internal experimental objects.

[0066] Furthermore, the fiber cluster to be measured is connected to a high-precision dynamometer, which is fixed on the experimental platform. After the ejector is turned on, the measurement is performed after the value is stabilized.

[0067] Furthermore, the wind tunnel device proposed in the present invention is a vertical wind tunnel design, which can simulate wind speeds at various heights and speeds, and occupies a small area, and can conveniently measure fiber wind resistance. Compared with the traditional horizontal wind tunnel, the vertical wind tunnel designed in this embodiment can apply gravity factors in the vertical direction, and will not cause the problem of accidental contact between the fiber and the side wall when measuring longer fibers in the horizontal wind tunnel due to gravity factors.

[0068] This embodiment proposes a wind tunnel measurement device specifically used for measuring the resistance of fiber filaments. By setting the fiber filaments in a stable section in the wind tunnel and designing the wind tunnel and the ejector, a stable wind field is generated in the stable section, thereby making the measurement more accurate and being able to simulate different wind speed conditions.

[0069] Implementation Method 2: See Figures 2 to 10 This embodiment is described. This embodiment further specifically describes the wind tunnel body described in the above embodiment.

[0070] Figure 2 The figure shows the three-dimensional structure diagram of the acceleration section. Figure 3The figure shows the schematic diagram of the structure of the acceleration section; it can be seen from the figure that the acceleration section is a channel with a gradually decreasing cross-sectional area. According to the principle of fluid continuity, when the fluid passes through the contraction section, its velocity will gradually increase. The air flow velocity can be increased from a lower inlet velocity to a supersonic or hypersonic state, providing conditions for measuring the fiber resistance environment. The overall length of the acceleration section is 900mm, the size at the inlet is 750mm×750mm, the overall thickness is 3mm, the material is stainless steel, and the size at the outlet is 314mm×314mm. The thickness of the two ear plates is 10mm, and their function is to connect with the support frame.

[0071] Figure 4 The figure shows the three-dimensional structure of the stable segment. Figure 5 The figure shows the internal structure of the stable segment. Figure 6 The figure shows a top view of the stabilizing section; it can be seen from the figure that the stabilizing section is the core area of ​​the wind tunnel device. The experimental object (fiber filament) is placed in the experimental section, and the airflow flows through the experimental object at a set speed and state, and the researchers measure the relevant data. When applied, a 70×70mm square small platform can be set at the bottom of the stabilizing section, and the square small platform is hollowed out to reduce the impact on the wind field. Tension sensors and test fibers are placed above the small platform. A small door with a handle is installed on the side opening to facilitate the placement and replacement of experimental items. A small section of 300×300 in the front of the stabilizing section is used for assembly with the acceleration section, and a 300mm square hole is opened inside the 314mm acceleration section.

[0072] Furthermore, in this embodiment, a 30 mm small hole is opened on the upper right end of the stable section for inserting the anemometer into the device at a vertical 90 degree angle to test the wind speed in the stable section wind field, which can make the measurement results more accurate and is more conducive to controlling the experimental environment.

[0073] Through analysis, this embodiment finds that the wind speed at the right end of the stable section and the wind speed at the working section are in the same stable state and have a similar wind speed range. Therefore, placing the anemometer at the right end of the stable section can more accurately reflect the wind speed of the working section. At the same time, after placing the anemometer in the working position (stable section), the additional impact of the anemometer and other external devices on the wind field due to being in the wind field can be reduced. For example, if the anemometer is placed at the front end, the stable wind field may become unstable, resulting in inaccurate measurement.

[0074] Figure 7 Shown is a front view of the diffuser section; Figure 8 The figure shows the side view of the diffuser section. It can be seen from the figure that the diffuser section is used to connect the stabilization section and the guider. The cross-sectional area of ​​the diffuser section gradually increases, which is opposite to the acceleration section. A bracket is provided at the bottom.

[0075] Fig. 9 Shown is a front view of the ejector; Fig.10 The figure shows the side view of the ejector; it can be seen from the figure that the ejector is a device used to use a high-speed and high-energy flow (liquid flow, air flow or other material flow) to eject another low-speed and low-energy flow. The jet flows into the mixing chamber through the contraction nozzle, and the surrounding is the ejected flow. Thus, the purpose of generating a stable wind field inside the entire device is achieved.

[0076] Furthermore, 10×15 small nozzles are evenly arranged on the ejector, and the high-speed airflow is used to eject the low-speed airflow, thereby achieving the purpose of accelerating the airflow in the device.

[0077] Furthermore, if Fig.11 As shown, each small nozzle on the ejector includes:

[0078] A high-pressure fluid inlet with a contraction design for receiving high-pressure fluid. When a high-pressure primary fluid (such as steam, compressed air or liquid) passes through the nozzle, the velocity of the fluid increases sharply and the pressure decreases due to the contraction design of the nozzle. According to the Bernoulli equation, when the fluid flows at high speed, the kinetic energy increases and the static pressure energy decreases, thus forming a low-pressure area at the nozzle outlet.

[0079] at least two low-pressure fluid inlets for receiving low-pressure fluid;

[0080] a mixing chamber connected to the high-pressure fluid inlet and the low-pressure fluid inlet for preliminarily mixing the fluids;

[0081] A mixing tube is connected to the mixing chamber and is used to further mix the fluids, that is, the primary fluid and the secondary fluid undergo intense turbulent mixing in the mixing chamber, momentum is transferred from the high-speed primary fluid to the low-speed secondary fluid, the speed of the mixed fluids tends to be balanced, and the pressure is restored.

[0082] A diffuser is connected to the mixing tube and is used to diffuse and discharge the mixed fluid, that is, the mixed fluid enters the diffusion chamber, the cross section of the diffusion chamber gradually expands, the velocity of the fluid decreases, and the pressure further increases. Finally, the mixed fluid is discharged from the ejector outlet at a higher pressure. Multiple ejector arrays are combined into a larger ejector.

[0083] The contraction design of the high-pressure fluid inlet includes: a contraction section, whose cross-sectional area gradually decreases to accelerate the fluid flow rate; and an inlet section connected to the contraction section for receiving the high-pressure fluid.

[0084] The cross-sectional area reduction ratio of the contraction section is adjustable to accommodate different fluid characteristics and mixing requirements.

[0085] The mixing chamber has at least one internal baffle for guiding fluid flow and promoting mixing, and cooperates with the contraction design of the high-pressure fluid inlet to optimize the mixing effect. The mixing tube has a gradually decreasing cross-sectional area to promote further mixing of the fluid. The diffuser has a gradually increasing cross-sectional area to reduce the fluid velocity and further mix the fluid.

[0086] Implementation method three, see Figure 12 to Figure 14 This embodiment is described. This embodiment specifically describes other components of a wind tunnel measuring device specifically used for measuring fiber filament resistance described in the above embodiment.

[0087] In practical application, it is also necessary to design an aluminum profile support frame. The wind tunnel body is set in the aluminum profile support frame. Fig.12 shown.

[0088] Fig.13 The figure shows the schematic diagram of the structure of the tensile gauge. The fiber cluster to be measured is connected to the tensile gauge, and the tensile gauge is fixed on the experimental platform. After the ejector is turned on, the measurement is performed after the value is stable.

[0089] To ensure the accuracy of the experimental conditions, this embodiment uses an anemometer to measure the wind speed in the device. Fig.14 As shown, through the coordinated work of the two anemometers, the wind speed conditions at different positions in the device can be measured more accurately, thereby providing more accurate wind speed data for the experiment and ensuring the reliability and accuracy of the experimental results.

[0090] Implementation method 4: See Figures 15 to 17 This embodiment is described. This embodiment is a specific application description of a wind tunnel measuring device specially used for measuring the resistance of fiber filaments proposed in the above embodiment.

[0091] like Fig.16 and 17 As shown, the wind tunnel body and the ejector are connected, the fiber cluster is placed in the stable section and connected to the tensile gauge, which is fixed on the experimental platform. After the ejector is turned on, the measurement is performed after the value is stable. At the same time, an anemometer is used to measure the wind speed in the device, and a corresponding system is used to monitor the wind speed in real time and set the wind speed value, as well as a corresponding data processing system, and a line graph is generated in real time through the feedback data of the tensile gauge.

[0092] The design wind speed range is 0~100m / s. When the working wind speed is 30m / s, the inlet wind speed is about 5m / s, and the acceleration section has a significant acceleration effect. Fig.15 As shown in the figure, it can be seen that a large area of ​​wind field with relatively stable wind speed was formed in the experimental section.

[0093] In summary, the present invention designs a wind tunnel measuring device specifically for measuring the resistance of fiber filaments. By setting the fiber filaments in a stable section in the wind tunnel and designing the wind tunnel and the ejector, a stable wind field is generated in the stable section, thereby making the measurement more accurate and being able to simulate different wind speed conditions.

[0094] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0095] The above description is only the implementation mode of the present invention and is not limited to the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A wind tunnel measuring device specially used for measuring the resistance of fiber filaments, characterized in that: It includes vertical wind tunnel body, ejector and high-precision dynamometer; The main body of the vertical wind tunnel includes an acceleration section, a stabilization section, and a diffusion section; The acceleration section is connected to the diffusion section through the stabilization section, and the other end of the diffusion section is connected to the ejector; The acceleration section is used to increase the low air flow velocity at the inlet to supersonic or hypersonic speed, and transmit it to the ejector through the stabilization section and the diffusion section in sequence; The ejector is used to use the high-speed and high-energy flow to eject the low-speed and low-energy flow in the wind tunnel body, so that the high-speed and high-energy flow and the low-speed and low-energy flow are mixed to form a stable wind field, and then returned to the stable section through the diffusion section; The stable section is used as the experimental section to place the fiber filaments, and a high-precision tensile gauge is connected to the fiber filaments.

2. A wind tunnel measuring device specially used for measuring fiber filament resistance according to claim 1, characterized in that: A channel with a gradually decreasing cross-sectional area is used as the acceleration section; The cross-sectional area at the entrance of the acceleration section is 750mm×750mm, the cross-sectional area at the exit is 314mm×314mm, and a 300mm square hole is also provided at the exit.

3. A wind tunnel measuring device specially used for measuring fiber filament resistance according to claim 2, characterized in that: An interface end is provided at the front part of the stabilizing section, and the size of the interface end is 300×300mm, which is used to connect with the square hole of the accelerating section.

4. A wind tunnel measuring device specially used for measuring fiber filament resistance according to claim 1, characterized in that: An anemometer is provided at the right end of the stable section to measure the wind speed within the stable section.

5. A wind tunnel measuring device specially used for measuring fiber filament resistance according to claim 1, characterized in that: A small hollow square platform of 70×70 mm is provided in the stabilizing section to carry fiber filaments and a high-precision dynamometer.

6. A wind tunnel measuring device specially used for measuring fiber filament resistance according to claim 1, characterized in that: A channel with gradually increasing cross-sectional area is used as the diffusion section.

7. A wind tunnel measuring device specially used for measuring fiber filament resistance according to claim 1, characterized in that: There are 10×15 small nozzles evenly arranged on the ejector.

8. A wind tunnel measuring device specially used for measuring fiber filament resistance according to claim 7, characterized in that: Each small nozzle includes at least one high-pressure fluid inlet having a converging design for receiving the high-pressure fluid; at least two low-pressure fluid inlets for receiving low-pressure fluid; A mixing chamber, used to be connected to the high-pressure fluid inlet and the low-pressure fluid inlet so as to preliminarily mix the high-pressure fluid and the low-pressure fluid; A mixing tube connected to the mixing chamber and used to further mix the fluid; The diffusion tube is used to be connected with the mixing tube and is used to diffuse and discharge the mixed fluid.

9. A wind tunnel measuring device specially used for measuring fiber filament resistance according to claim 8, characterized in that: The constriction design of the high pressure fluid inlet includes: The contraction section, whose cross-sectional area gradually decreases to accelerate the flow rate of the fluid; The inlet section is connected to the contraction section and is used for receiving the high-pressure fluid.

10. A wind tunnel measuring device specially used for measuring fiber filament resistance according to claim 8, characterized in that: The mixing chamber has at least one internal baffle for guiding fluid flow and promoting mixing; the diffuser has a gradually increasing cross-sectional area to reduce fluid velocity and further mix the fluid.

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