A wind tunnel dynamic pressure measuring device and measuring method

Abstract

The application discloses a wind tunnel dynamic pressure measuring device and a measuring method, wherein a placing groove is arranged on a rack, a side surface of the rack is provided with a plurality of mounting holes, the mounting holes are communicated with the placing groove, one end of a probe is detachably connected with the mounting holes, and the other side surface of the rack is connected with a hollow supporting rod. The device has the advantages that the influence of the distance between a reference probe and a measuring probe on wind tunnel fluctuating pressure testing can be researched, the influence of different lengths of cavities in front of sensors on wind tunnel fluctuating pressure testing can be researched, and the device also has the ability of wind tunnel total pressure and static pressure fluctuating pressure testing. The device is small and is suitable for various wind tunnel fluctuating pressure testing, and effectively guarantees the strict requirements of high precision, high response frequency and small flow field interference of wind tunnel dynamic pressure flow field.

Description

Technical Field

[0001] This invention relates to wind tunnel testing, specifically to a wind tunnel dynamic pressure measurement device and method. Background Technology

[0002] In supersonic vehicle design, the boundary layer transition location is a crucial parameter, and its characteristics are particularly important for next-generation supersonic maneuvering and stealth vehicles. Low-turbulence, low-noise supersonic wind tunnels, also known as "silent" supersonic wind tunnels, are essential equipment for studying boundary layer transition under supersonic conditions. The turbulence in their flow field must reach the level of air turbulence at the vehicle's cruising altitude.

[0003] In a "silent" supersonic wind tunnel, the region with very small static pressure fluctuations is called the "silent" region. The "silent" characteristic refers to this very small static pressure fluctuation value. Currently, flow field parameters in wind tunnels are typically measured using a pneumatic probe. The pneumatic probe is placed in the wind tunnel flow field, and the air pressure of the wind tunnel flow field is obtained through pressure-sensing holes on the probe. The air pressure is then led out of the tunnel using a pressure-sensing tube. A measurement system equipped with pressure sensors, amplifiers, and data acquisition devices is then installed outside the tunnel to collect and process the air pressure data, thereby achieving the measurement of wind tunnel flow field parameters.

[0004] However, existing measuring devices and methods have the following problems:

[0005] 1. The dynamic pressure measurement at different lateral positions in the wind tunnel cannot be achieved, and the influence of the distance between the reference probe and the measuring probe on the test cannot be investigated.

[0006] 2. The interference introduced by the "silent" supersonic wind tunnel flow field dynamic pressure measurement test is too great, making it difficult to guarantee the accuracy of dynamic pressure measurement;

[0007] 3. It is not possible to measure the pulsation of static pressure and the pulsation of total wind tunnel pressure simultaneously;

[0008] 4. It is not possible to investigate the effect of cavities of different lengths at the probe tip on the test. Summary of the Invention

[0009] One objective of this invention is to provide a wind tunnel dynamic pressure measurement device and method. By setting up probes and a frame, this device can realize dynamic pressure measurement at different lateral positions in the wind tunnel and explore the influence of the distance between the reference probe and the measuring probe on the test.

[0010] This objective is achieved using the following technical solution:

[0011] Existing measuring devices include probes and frames, which measure the dynamic pressure in a wind tunnel through the connection of the probes and frames. However, their measurement scenarios are limited and cannot explore the impact of various conditions on the dynamic pressure measurement in a wind tunnel. Therefore, the inventors have developed a measuring device that includes a measuring probe, a reference probe, and a frame. The frame has a placement slot, and one side of the frame has several mounting holes that communicate with the placement slot. The mounting holes are detachably connected to one end of the probe. The other side of the frame is connected to an internally hollow support rod, which is also connected to the frame. In use, by connecting the measuring probe and the reference probe to the mounting holes at different positions on the frame, the influence of the distance between the reference probe and the measuring probe on the pulsating pressure test can be realized, and dynamic pressure measurement at different lateral positions in the wind tunnel can be achieved simultaneously.

[0012] Furthermore, measurements typically focus on the pulsation of static pressure in the wind tunnel, with less emphasis on the pulsation of total pressure. This device uses a detachable measuring probe with a front and a rear section. To measure static pressure, the front section is replaced with the static pressure front section; to measure total pressure, the front section is replaced with the total pressure front section. Both the static pressure and total pressure front sections have airflow sensing chambers. The rear section of the measuring probe has a communicating inner cavity and a first mounting cavity for installing a differential pressure sensor. When the rear section is connected to the front section, the airflow sensing cavity communicates with the first mounting cavity.

[0013] For the static pressure front section, the front end of the static pressure front section has a chamfer on the side. The airflow sensing cavity has four through holes evenly distributed along the circumference of the static pressure front section. The rear end of the static pressure front section has an inner cavity that is connected to the four through holes. When the static pressure front section is connected to the rear end of the measuring probe, the first mounting cavity is connected to the four through holes and the inner cavity of the static pressure front section.

[0014] For the front section of the total pressure system, the front end of the front section has a chamfered side, and the rear end of the front section has an inner cavity. The airflow sensing cavity is a groove located at the front end, and the groove communicates with the inner cavity at the rear end. The groove at the front end is used to sense the airflow. When the front section of the total pressure system is connected to the rear section of the measuring probe, the first mounting cavity communicates with the groove of the front section of the total pressure system and the inner cavity at the rear end.

[0015] Therefore, by replacing the front section of the measuring probe as needed, the pulsation of static pressure and the pulsation of total wind tunnel pressure can be measured.

[0016] Furthermore, a measurement adjustment ring connects the front and rear sections of the measurement probe. Several adjustment rings are located at the connection between the front and rear sections of the measurement probe and are used to adjust the length of the inner cavity of the front section. When it is necessary to investigate the effect of different cavity lengths at the probe tip on the test, this can be done by adjusting the number of adjustment rings.

[0017] In the above structure, the structure of the reference probe matches that of the measuring probe. The reference probe includes a detachably connected front section and a rear section. The front section has an airflow sensing cavity, and the rear section has an inner cavity. When the front and rear sections are connected, the airflow sensing cavity communicates with the inner cavity. A reference adjustment ring connects the front and rear sections. The structure of the reference probe is similar to that of the measuring probe, the main difference being that the length of each segment of the reference probe is shorter than that of the measuring probe, and the rear section of the reference probe does not have a first mounting cavity for mounting a differential pressure sensor; that is, the inner cavity of the reference probe is a through hole with a uniform cross-section and no mounting steps.

[0018] Preferably, one end of the mounting hole is connected to the probe, and the other end is connected to an adapter, which is used to connect the probe and the T-connector. The T-connector, combined with the measurement method, allows the device to directly replace the front section of the measuring probe, the front section of the reference probe, and add or remove the measuring adjustment ring and the reference adjustment ring when measuring the influence of different length cavities at the probe tip on the test, as well as the pulsation of static pressure and the pulsation of the total pressure in the wind tunnel. This eliminates the need to adjust the connections of cables and air pipes within the frame.

[0019] Specifically, the measurement method includes the following steps:

[0020] Connect one end of the measuring probe and the reference probe to the mounting holes on the rack, respectively; the placement slot is equipped with a mounting slot for installing the absolute pressure sensor. Connect the tee to the mounting hole connected to the reference probe; connect the air tube of the differential pressure sensor and the air tube of the absolute pressure sensor inside the measuring probe to the two ports of the tee, respectively; the differential pressure sensor cable and the absolute pressure sensor cable are led out through the inside of the support rod.

[0021] This makes adjustments much easier; you can simply adjust the front section of the measuring probe, the front section of the reference probe, or add or remove the measuring adjustment ring and the reference adjustment ring.

[0022] On the other hand, the probe diameter of this device is less than or equal to 5 mm. The width of the support frame is less than or equal to 70 mm, and the height is less than or equal to 10 mm. This compact device is suitable for testing the effects of pulsating pressure in various wind tunnels (including total and static pressure), with particularly significant advantages in small supersonic wind tunnels. During the measurement process, it effectively avoids interference introduced by the measuring device itself, further improving the accuracy of dynamic pressure measurements in "silent" supersonic wind tunnels.

[0023] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0024] This invention discloses a wind tunnel dynamic pressure measurement device and method. The device is capable of studying the influence of the distance between the reference probe and the measuring probe on the pulsating pressure test of a wind tunnel (including total and static pressure); it is also capable of studying the influence of cavities of different lengths (or heights) at the sensor front end on the pulsating pressure test of a wind tunnel (including total and static pressure); and it also has the capability to perform pulsating pressure tests on both total and static pressure in wind tunnels. This compact device is suitable for testing the effects of pulsating pressure in various wind tunnels (including total and static pressure), effectively ensuring the stringent requirements of high precision, high response frequency, and low flow field interference in the dynamic pressure flow field of the wind tunnel. Attached Figure Description

[0025] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0026] Figure 1 This is a schematic diagram of the device structure in Example 1;

[0027] Figure 2 This is a schematic diagram of the frame structure in Example 1;

[0028] Figure 3 This is a schematic diagram of the measurement probe structure in Example 2;

[0029] Figure 4 This is a schematic diagram of the reference probe structure in Example 2;

[0030] Figure 5 This is a schematic diagram of the static pressure front section structure in Example 2;

[0031] Figure 6 This is a schematic diagram of the total pressure front section structure in Example 2;

[0032] Figure 7 This is a schematic diagram of the structure in Example 3, where the measuring probe and the reference probe are respectively connected to a measuring adjustment ring and a reference adjustment ring;

[0033] Figure 8 This is a schematic diagram of the T-connector connection method in Example 5.

[0034] The attached diagram shows the markings and corresponding component names:

[0035] 1-Frame, 2-Placement slot, 3-Mounting hole, 4-Mounting slot, 5-Connecting hole, 6-Connecting cover, 7-Adapter, 8-Measuring probe, 81-Front section of measuring probe, 82-Measuring adjustment ring, 83-Rear section of measuring probe, 9-Reference probe, 91-Front section of reference probe, 92-Reference adjustment ring, 93-Rear section of reference probe, 10-Support rod, 11-Front section of total pressure, 12-Front section of static pressure, 13-Tee pipe. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0037] In the description of this invention, it should be understood that the terms "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0038] Example 1

[0039] like Figure 1 As shown, this device includes probes and a frame. The probes include a measuring probe 8 and a reference probe 9. The device also includes a frame 1, the structure of which is as follows: Figure 2 As shown, the frame 1 has a placement slot 2, and the placement slot 2 contains a mounting slot 4 for installing an absolute pressure sensor. The placement slot 2 is connected to the connecting cover 6 by bolts. One side of the frame 1 has several mounting holes 3, which communicate with the placement slot 2 and are detachably connected to one end of the probe. The other side of the frame 1 is connected to an internally hollow support rod 10, which is connected to the frame. When connected, the support rod and the probe are parallel to each other.

[0040] In one or more embodiments, the measuring probe 8 and the reference probe 9 are threadedly connected to the mounting hole 3.

[0041] In one or more embodiments, a connecting hole 5 is provided on the other side of the frame 1 opposite to the mounting hole. The connecting hole 5 is used to connect the support rod 10. In some embodiments, the connecting hole 5 is threaded or welded to the support rod 10.

[0042] In use, the effect of the distance between the reference probe and the measurement probe on the test can be investigated by connecting the measurement probe and the reference probe to different mounting holes.

[0043] During the measurement process, airflow flows in through the probe head, and the pressure sensor acquires the incoming airflow gust parameters in real time. The airflow pressure signal at the probe head is output as a voltage signal. Specifically, during the blowing process (when measuring static pressure), the airflow enters the airflow sensing chambers of the two probes through four through holes (i.e., static pressure holes) opened at the front sections of the measuring probe and the reference probe. The differential pressure sensor at the front section of the measuring probe (which includes both a measuring end and a reference end) senses the airflow pressure. Inside the reference probe, the airflow is led through the airflow sensing chamber and inner cavity to the three-way tube 13. The three-way tube is connected to the reference end of the differential pressure sensor and the sensing end of the absolute pressure sensor at the front section of the measuring probe (due to the static pressure holes of the measuring probe and the reference probe). Since the distance between the probes is relatively short, it is assumed that the static pressure sensed at the static pressure orifices of the two probes is the same. Therefore, the static pressure sensed by the reference probe is used as the pressure at the reference end of the differential pressure sensor of the measuring probe. The pressure measured by the differential pressure sensor at the front of the measuring probe is the difference between the pressure at the measuring end and the pressure at the reference end. The pressure at the measuring end is the actual airflow pressure (including pulsations), while the pressure at the reference end is the steady-state airflow pressure. The difference between the two is the dynamic pressure value. The relevant pressure is converted into a voltage signal by the differential pressure sensor and the absolute pressure sensor, and then analyzed and converted by the data acquisition system before being output. Thus, the dynamic static pressure is measured, and the absolute pressure at the static pressure orifices of both probes is simultaneously measured.

[0044] Example 2

[0045] Based on the above embodiments, such as Figure 3 The measurement probe 8 shown includes a detachably connected front section 81 and a rear section 83. The front section 81 is provided with an airflow sensing cavity, and the rear section 83 is provided with a communicating inner cavity and a first mounting cavity for mounting a differential pressure sensor. When the rear section 83 is connected to the front section 81, the airflow sensing cavity communicates with the first mounting cavity. Correspondingly, the structure of the reference probe 9 is as follows... Figure 4 As shown, the reference probe 9 includes a detachably connected front section 91 and a rear section 93. The front section 91 has an airflow sensing cavity, and the rear section 93 has an inner cavity. When the front section 91 and the rear section 93 are connected, the airflow sensing cavity communicates with the inner cavity. The reference probe is similar in structure to the measurement probe, the main difference being that the length of each segment of the reference probe is shorter than that of the measurement probe, and the rear section of the reference probe does not have a first mounting cavity for mounting a differential pressure sensor; that is, the inner cavity of the reference probe is a through hole with a uniform cross-section and no mounting steps.

[0046] In this embodiment, the measuring probe front section 81 is either the static pressure front section 12 or the total pressure front section 11. The static pressure front section 12 or the total pressure front section 11 can be replaced as needed during use.

[0047] In one or more embodiments, the hydrostatic front section is as follows: Figure 5As shown, the front end of the static pressure front section is conical, and the airflow sensing cavity has four through holes evenly distributed along the circumference of the static pressure front section. The rear end of the static pressure front section is provided with an inner cavity, which is connected to the four through holes. When the static pressure front section is connected to the rear section 83 of the measuring probe, the first mounting cavity is connected to the four through holes and the inner cavity of the static pressure front section.

[0048] In one or more embodiments, the total pressure front section is as follows: Figure 6 As shown, the front end of the total pressure front section has a chamfer on its side, and the rear end of the total pressure front section has an inner cavity. The airflow sensing cavity is a groove located at the front end, and the groove communicates with the inner cavity at the rear end. The groove at the front end is used to sense the airflow. When the total pressure front section is connected to the rear section 83 of the measuring probe, the first mounting cavity communicates with the groove of the total pressure front section and the inner cavity at the rear end.

[0049] By replacing the front section 81 of the measuring probe as needed, the pulsation of static pressure and the pulsation of total wind tunnel pressure can be measured.

[0050] In one or more embodiments, the rear section 83 of the measuring probe and the front section 81 of the measuring probe are connected by threads.

[0051] In one or more embodiments, the front section 91 and the rear section 93 of the reference probe are connected by threads.

[0052] Example 3

[0053] Based on the above embodiments, such as Figure 7 As shown, a measurement adjustment ring 82 connects the front section 81 and the rear section 83 of the measurement probe. A reference adjustment ring 92 connects the front section 91 and the rear section 93 of the reference probe. The number of measurement adjustment rings 82 and reference adjustment rings 92 is varied. The more measurement adjustment rings connected between the front section 81 and the rear section 83 of the measurement probe, the longer the inner cavity length of the front section 81. By adjusting the inner cavity length of the front section of the probe using the vehicle adjustment ring and the reference adjustment ring, the influence of different cavity lengths at the probe tip on the test can be investigated.

[0054] In some embodiments, the reference adjustment ring 92 is threadedly connected to both the front section 91 and the rear section 93 of the reference probe.

[0055] In some embodiments, the measuring adjustment ring 82 is threadedly connected to both the front section 81 and the rear section 83 of the measuring probe.

[0056] Example 4

[0057] Based on the above embodiments, the maximum diameter of the probe of this device is 5mm, the width of the frame 1 is 60mm, and the height is 8mm.

[0058] In one or more embodiments, the maximum diameter of the probe is 4 mm, the width of the rack 1 is 60 mm, and the height is 8 mm.

[0059] In one or more embodiments, the maximum diameter of the probe is 5 mm, the width of the frame 1 is 70 mm, and the height is 10 mm.

[0060] During the experimental investigation, the inventors discovered that when the maximum diameter of the probe does not exceed 5 mm and the width and height of the frame do not exceed 70 mm and 10 mm respectively, the interference introduced in the dynamic pressure measurement test of the "silent" supersonic wind tunnel flow field is small, which can better ensure the accuracy of dynamic pressure measurement.

[0061] Example 5

[0062] Based on the above embodiments, such as Figure 7 As shown, one end of the mounting hole 3 is connected to the probe, and the other end of the mounting hole 3 is connected to the adapter 7, which is used to connect the probe and the tee tube 13. The adapter 7 and the mounting hole are connected by threads, and can be further connected by bolts after connection.

[0063] When in use, the measurement method of this device includes the following steps:

[0064] Connect one end of the measuring probe 8 and the reference probe 9 to the mounting hole 3 of the frame 1 respectively;

[0065] like Figure 8 As shown, the three-way tube 13 is connected to the mounting hole 3 connected to the reference probe 9;

[0066] Connect the air tubes of the differential pressure sensor and the absolute pressure sensor inside the measuring probe 8 to the two ports of the tee tube 13, respectively. After connection, fix the absolute pressure sensor to the mounting groove with glue, and lead the differential pressure sensor cable and the absolute pressure sensor cable out through the inner cavity of the support rod 10. The reference end of the differential pressure sensor air tube is connected to the tee tube.

[0067] After confirming that the upload is complete and that everything is correct, tighten the connecting cover 6 of the rack with screws to seal the rack.

[0068] in:

[0069] When static pressure and total pressure pulsating pressure transformation tests are required, the above wiring status does not need to be adjusted. Only the front section of the measuring probe and the front section of the reference probe need to be replaced with the corresponding front section, such as the total pressure front section or the static pressure front section.

[0070] When it is necessary to test the effect of the probe front section inner cavity length (or height) on the pulsating pressure (including total pressure and static pressure), there is no need to adjust the above wiring state. Simply disconnect the probe front section from the rear section and add different numbers of adjustment rings.

[0071] When it is necessary to investigate the effect of the spacing between the reference probe and the measuring probe on the pulsating pressure (including total pressure and static pressure), the above wiring configuration needs to be adjusted. This can be achieved by adjusting the reference probe or the measuring probe individually, or by adjusting both probes. The relevant steps are as follows:

[0072] Option 1: Adjust the reference probe 9 separately. First, disconnect the adapter 7 from the tee tube 13, leaving everything else unchanged. Then, disconnect the reference probe 9 from the mounting hole 3 of the bracket. After determining the installation position of the reference probe, install the reference probe into the other mounting hole of the bracket. Then, connect the adapter and the tee tube 13 in sequence to complete the adjustment.

[0073] Option 2: Adjust the measuring probe separately. First, disconnect the air tube of the differential pressure sensor from the three-way tube 13, and release the differential pressure sensor cable through the support rod. Then, disconnect the reference probe from the mounting hole of the rack. Further, release the air tube and cable of the differential pressure sensor through the original mounting hole of the rack, leaving everything else unchanged. After determining the installation position of the measuring probe, lead the air tube and cable of the differential pressure sensor through another mounting hole of the rack to the inner cavity of the rack, and complete the installation of the measuring probe and the mounting hole. Further, connect the air tube of the differential pressure sensor to the three-way tube 13, and then introduce the differential pressure sensor cable into the inner cavity of the support rod to complete the adjustment.

[0074] Option 3: Simultaneously adjust the reference probe and the measuring probe. First, disconnect the adapter 7, the air tube of the differential pressure sensor, and the three-way tube 13. Then, release the differential pressure sensor cable through the support rod. Disconnect the reference probe and the measuring probe from their respective mounting holes on the rack. Release the air tube and cable of the differential pressure sensor through the original mounting holes on the rack, leaving everything else unchanged. After determining the new mounting positions of the reference probe and the measuring probe, lead the air tube and cable of the differential pressure sensor through the new mounting holes on the rack to the inner cavity of the rack. Complete the installation of the reference probe and the measuring probe with their respective new mounting holes on the rack. Further connect the air tube of the differential pressure sensor to the three-way tube 13, the mounting hole of the reference probe to the adapter, and the adapter to the three-way tube 13. Then, introduce the differential pressure sensor cable into the inner cavity of the support rod to complete the adjustment.

[0075] The term "first" as used in this document is merely for clarity of description and is not intended to restrict any order or emphasize importance. Furthermore, the term "connection" as used herein, unless otherwise specified, can refer to a direct connection or an indirect connection via other components.

[0076] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A wind tunnel dynamic pressure measurement device, comprising a probe and a frame, characterized in that, The probes include a measuring probe (8) and a reference probe (9). The device also includes a frame (1), on which a placement slot (2) is provided. A plurality of mounting holes (3) are provided on one side of the frame (1). The mounting holes (3) are connected to the placement slot (2). The mounting holes (3) are detachably connected to one end of the probe. The other side of the frame (1) is connected to the hollow support rod (10). The support rod (10) is connected to the frame. The measuring probe (8) includes a detachably connected front section (81) and a rear section (83) of the measuring probe. A measuring adjustment ring (82) is connected between the front section (81) and the rear section (83) of the measuring probe. The reference probe (9) includes a detachably connected front section (91) and a rear section (93) of the reference probe. A reference adjustment ring (92) is connected between the front section (91) and the rear section (93) of the reference probe.

2. The wind tunnel dynamic pressure measurement device according to claim 1, characterized in that, The placement slot (2) is provided with a mounting slot (4) for installing an absolute pressure sensor.

3. The wind tunnel dynamic pressure measurement device according to claim 1, characterized in that, One end of the mounting hole (3) is connected to the probe, and the other end of the mounting hole (3) is connected to the adapter (7), which is used to connect the probe and the three-way tube (13).

4. The wind tunnel dynamic pressure measurement device according to claim 1, characterized in that, The diameter of the probe is less than or equal to 5 mm.

5. The wind tunnel dynamic pressure measurement device according to claim 1, characterized in that, The frame (1) has a width of less than or equal to 70 mm and a height of less than or equal to 10 mm.

6. A method for measuring dynamic pressure in a wind tunnel, characterized in that, The measuring device comprising any one of claims 1-5 includes the following steps: Connect one end of the measuring probe (8) and the reference probe (9) to the mounting hole (3) of the frame (1), respectively; Connect the tee tube (13) to the mounting hole (3) where the reference probe (9) is connected; Connect the air tube of the differential pressure sensor and the air tube of the absolute pressure sensor inside the measuring probe (8) to the two ports of the three-way tube (13); The differential pressure sensor cable and the absolute pressure sensor cable are led out through the support rod (10).

Images