A non-directional two-dimensional flow field static pressure measuring probe and a measuring method thereof

Abstract

The application belongs to the technical field of undirectional two-dimensional flow field static pressure measurement, and particularly relates to an undirectional two-dimensional flow field static pressure measurement probe and a measurement method thereof, wherein the probe comprises a supporting rod, one end of which is a pressure receiving end, and the other end of which is a pilot gas measurement end; the outer wall of the pressure receiving end is provided with three fan-shaped slits; the three fan-shaped slits are distributed in the circumferential direction of the supporting rod, and the fan-shaped angle is 120°; the end of the pilot gas measurement end is provided with a measurement pilot gas hole; the measurement pilot gas hole is located on the axis of the supporting rod, is perpendicular to the plane where the three fan-shaped slits are located, and is connected with the three fan-shaped slits.

Description

Technical Field

[0001] This application belongs to the field of non-directional two-dimensional flow field static pressure measurement technology, specifically relating to a non-directional two-dimensional flow field static pressure measurement probe and its measurement method. Background Technology

[0002] In some cases, the flow field is approximated as a two-dimensional flow field, where the airflow only flows in a plane, has no velocity component in the plane normal, and the flow direction in the plane is random and changes with time.

[0003] Currently, most methods use three orifices for hydrostatic measurements of two-dimensional flow fields, which has the following drawbacks:

[0004] 1) The three-hole needle is composed of three Φ1 pressure tubes welded together in parallel. The structure has poor reliability. During storage, assembly and disassembly, it is easily deformed by external forces, which affects the accuracy of measurement.

[0005] 2) The validity of the measurement results can only be guaranteed within a flow angle range of ±25°, which is difficult to meet the static pressure measurement requirements of non-directional two-dimensional flow fields over a large range;

[0006] 3) When performing wind tunnel calibration, it is necessary to perform calibration in steps of 0.1 Mach number and 5° airflow angle within the calibration Mach number range and airflow angle range. There are many calibration points, resulting in low calibration efficiency and high cost.

[0007] 4) The measurement accuracy is greatly affected by the installation and positioning accuracy, and it requires combining test data and calibration data, and using a complex numerical algorithm to obtain the static pressure value. The process is complicated and the measurement accuracy is low.

[0008] This application is made in view of the aforementioned technical deficiencies.

[0009] It should be noted that the above background information is only used to assist in understanding the inventive concept and technical solution of this application, and it does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above information was disclosed on the filing date of this application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0010] The purpose of this application is to provide a non-directional two-dimensional flow field static pressure measurement probe and its measurement method to overcome or mitigate at least one of the known technical defects.

[0011] The technical solution of this application is:

[0012] One aspect provides a non-directional two-dimensional flow field hydrostatic measurement probe, comprising:

[0013] The support rod has a pressure sensing end at one end and an air duct measurement end at the other end.

[0014] The outer wall of the pressure sensing end has three fan-shaped slits;

[0015] Three fan-shaped slits are distributed along the circumference of the support rod, with a fan angle of 120°.

[0016] The end of the air expiratory measuring device has an air expiratory hole for measurement;

[0017] The measuring air intake is located on the axis of the support rod. The axis of the measuring air intake is perpendicular to the plane containing the three fan-shaped slits and connects the three fan-shaped slits.

[0018] According to at least one embodiment of this application, in the above-mentioned non-directional two-dimensional flow field static pressure measurement probe, the air bleed measurement end and the pressure sensor and its data acquisition system are connected by a threaded fit using a pressure cap, and the air bleed measurement hole and the pressure sensor and its data acquisition system are fitted with a ball-head conical surface.

[0019] According to at least one embodiment of this application, in the above-described non-directional two-dimensional flow field hydrostatic measurement probe, the height of the three fan-shaped slits is 1 mm.

[0020] According to at least one embodiment of this application, the above-described non-directional two-dimensional flow field hydrostatic measurement probe further includes:

[0021] The mounting bracket is fitted onto the outer circumference of the support rod and welded to it. It can be in the form of a flange or a ball head with a threaded cap.

[0022] On the other hand, a non-directional two-dimensional flow field static pressure measurement method is provided, implemented based on any of the above-mentioned non-directional two-dimensional flow field static pressure measurement probes, including:

[0023] Wind tunnel calibration steps:

[0024] A non-directional two-dimensional flow field static pressure measurement probe is installed in the wind tunnel, so that the pressure sensing end of the support rod extends into the wind tunnel, and the plane containing the three fan-shaped slits on the outer wall of the pressure sensing end is parallel to the wind tunnel flow field.

[0025] Adjust the wind tunnel Mach number to the lower limit of the calibrated Mach number range;

[0026] After the Mach number in the wind tunnel stabilizes, record the actual total pressure in the wind tunnel. Wind tunnel true static pressure And the use of pressure sensors and their data acquisition systems to collect wind tunnel static pressure measurements. ;

[0027] Increase the wind tunnel Mach number and record and collect multiple sets of real total wind tunnel pressure. wind tunnel real static pressure Wind tunnel static pressure measurement values Until the wind tunnel Mach number reaches the upper limit of the calibrated Mach number range;

[0028] Steps for hydrostatic measurement of non-directional two-dimensional flow field:

[0029] Place the non-directional two-dimensional flow field static pressure measurement probe in the non-directional two-dimensional flow field, so that the pressure sensing end of the support rod extends into the non-directional two-dimensional flow field, and the plane of the three fan-shaped slits on the outer wall of the pressure sensing end is located in the plane of the non-directional two-dimensional flow field.

[0030] The static pressure measurements of a non-directional two-dimensional flow field are acquired using a pressure sensor and its data acquisition system. ;

[0031] Static pressure measurement data processing steps:

[0032] Calculate the ratio of the actual static pressure to the actual total pressure in the wind tunnel at different Mach numbers. ;

[0033] Calculate the ratio of the measured static pressure to the actual total pressure in the wind tunnel at different Mach numbers. ;

[0034] Fitting different wind tunnel Mach numbers , ,get , The calculation relationship between them;

[0035] Calculate the ratio of the static pressure measurement value to the total pressure of the non-directional two-dimensional flow field. ,in, The total pressure of the non-directional two-dimensional flow field;

[0036] exist , In the calculation relationship between them, with replace Calculations yielded And then in In China, with replace , calculated As the real static pressure of a non-directional two-dimensional flow field .

[0037] According to at least one embodiment of this application, in the above-described non-directional two-dimensional flow field static pressure measurement method, in the wind tunnel calibration step, before installing the non-directional two-dimensional flow field static pressure measurement probe into the wind tunnel, the non-directional two-dimensional flow field static pressure measurement probe is inspected, including structural integrity inspection and air duct inspection.

[0038] Multiple sets of actual total pressure data from the wind tunnel were collected each time. wind tunnel real static pressure Wind tunnel static pressure measurement values Before, judge , , Check for any abnormalities. If so, re-inspect the two-dimensional flow field static pressure measuring device and its related air intake pipeline.

[0039] like Greater than Or different wind tunnel Mach numbers / , / If the coordinate points formed deviate from the straight line, then determine... , , Exception, otherwise check , , normal. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of a non-directional two-dimensional flow field static pressure measurement probe provided in an embodiment of this application;

[0041] Figure 2 yes Figure 1 AA view;

[0042] Figure 3 This is a schematic diagram of the wind tunnel calibration steps in the non-directional two-dimensional flow field static pressure measurement method provided in the embodiments of this application;

[0043] Figure 4 This is a schematic diagram of the static pressure measurement data processing steps in the non-directional two-dimensional flow field static pressure measurement method provided in the embodiments of this application;

[0044] in:

[0045] 1-Support rod; 2-Mounting base.

[0046] To better illustrate this embodiment, some parts in the accompanying drawings may be omitted, enlarged, or reduced, and do not represent the actual size of the product. Furthermore, the accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent. Detailed Implementation

[0047] To make the technical solution and advantages of this application clearer, the technical solution of this application will be described in a clearer and more complete manner below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some embodiments of this application, and are only used to explain this application, not to limit this application. It should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings. Other related parts can be referred to the general design. In the absence of conflict, the embodiments and technical features in the embodiments of this application can be combined with each other to obtain new embodiments.

[0048] Furthermore, unless otherwise defined, the technical or scientific terms used in this application description shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "upper," "lower," "left," "right," "center," "vertical," "horizontal," "inner," and "outer," etc., used in this application description to indicate relative direction or positional relationship are used only to indicate relative orientation or positional relationship, and do not imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. When the absolute position of the described object changes, its relative positional relationship may also change accordingly, and therefore should not be construed as a limitation on this application. The terms "first," "second," "third," and similar terms used in this application description are used only for descriptive purposes to distinguish different components, and should not be construed as indicating or implying relative importance. The terms "a," "one," or "the," etc., used in this application description should not be construed as an absolute limitation on quantity, but should be construed as indicating the existence of at least one. The terms "including," "comprising," etc., used in this application description mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, without excluding other elements or objects.

[0049] Furthermore, it should be noted that, unless otherwise explicitly specified and limited, terms such as “installation,” “connection,” and “linkage” used in the description of this application should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; or it can be a connection within two components. Those skilled in the art can understand its specific meaning in this application according to the specific circumstances.

[0050] The following is in conjunction with the appendix Figures 1 to 4 This application will be described in further detail.

[0051] One aspect provides a non-directional two-dimensional flow field hydrostatic measurement probe, comprising:

[0052] Support rod 1 has a pressure sensing end at one end and an air duct measurement end at the other end;

[0053] The outer wall of the pressure sensing end has three fan-shaped slits;

[0054] Three fan-shaped slits are distributed around the circumference of the support rod 1, with a fan angle of 120°;

[0055] The end of the air expiratory measuring device has an air expiratory hole for measurement;

[0056] The measuring air intake is located on the axis of support rod 1. The measuring air intake is perpendicular to the plane containing the three fan-shaped slits and connects the three fan-shaped slits.

[0057] Using the non-directional two-dimensional flow field static pressure measurement probe disclosed in the above embodiments, non-directional two-dimensional flow field static pressure measurement can be performed by referring to the following non-directional two-dimensional flow field static pressure measurement method, including:

[0058] Wind tunnel calibration steps:

[0059] Confirm the calibration Mach number range, for example, it could be 0.2 to 0.6 Ma;

[0060] The non-directional two-dimensional flow field static pressure measurement probe is inspected, including structural integrity checks and air intake path checks.

[0061] A non-directional two-dimensional flow field static pressure measurement probe is installed in the wind tunnel, so that the pressure sensing end of the support rod 1 extends into the wind tunnel, and the plane containing the three fan-shaped slits on the outer wall of the pressure sensing end is parallel to the wind tunnel flow field.

[0062] Adjust the wind tunnel Mach number to the lower limit of the calibrated Mach number range;

[0063] Record the actual total pressure in the wind tunnel 10 seconds after the Mach number stabilizes. Wind tunnel true static pressure And the use of pressure sensors and their data acquisition systems to collect wind tunnel static pressure measurements. ;

[0064] judge , , Check for any abnormalities. If so, re-examine the two-dimensional flow field static pressure measurement device and its related air intake pipelines. If not, gradually increase the wind tunnel Mach number in steps of 0.1 Ma and record multiple sets of the wind tunnel's actual total pressure. wind tunnel real static pressure Wind tunnel static pressure measurement values Until the wind tunnel Mach number reaches the upper limit of the calibrated Mach number range;

[0065] like Greater than Or different wind tunnel Mach numbers / , / If the coordinate points formed deviate from the straight line, then determine... , , Exception, otherwise check , , normal;

[0066] Steps for hydrostatic measurement of non-directional two-dimensional flow field:

[0067] Place the non-directional two-dimensional flow field static pressure measurement probe in the non-directional two-dimensional flow field, so that the pressure sensing end of the support rod 1 extends into the non-directional two-dimensional flow field, and the plane where the three fan-shaped slits on the outer wall of the pressure sensing end are located is in the plane of the non-directional two-dimensional flow field.

[0068] The static pressure measurements of a non-directional two-dimensional flow field are acquired using a pressure sensor and its data acquisition system. ;

[0069] Static pressure measurement data processing steps:

[0070] Calculate the ratio of the actual static pressure to the actual total pressure in the wind tunnel at different Mach numbers. ;

[0071] Calculate the ratio of the measured static pressure to the actual total pressure in the wind tunnel at different Mach numbers. ;

[0072] Fitting different wind tunnel Mach numbers , ,get , The calculation relationship between them;

[0073] Calculate the ratio of the static pressure measurement value to the total pressure of the non-directional two-dimensional flow field. ,in, The total pressure of the non-directional two-dimensional flow field;

[0074] exist , In the calculation relationship between them, with replace Calculations yielded And then in In China, with replace , calculated As the real static pressure of a non-directional two-dimensional flow field .

[0075] In the non-directional two-dimensional flow field static pressure measurement probe disclosed in the above embodiments, pressure is sensed by three fan-shaped slits formed at the pressure sensing end of the support rod 1. The structure has good reliability, is not easily damaged by external forces, and can ensure the accuracy of the measurement results. Moreover, the fan-shaped slits have a large opening range and can construct a flow field that approximates airflow through a flat wall surface. The static pressure measurement is similar to the classic wall static pressure measurement form. Through simulation analysis and wind tunnel calibration test verification, for different flow directions in the two-dimensional flow field, the fluctuation of the measured pressure value does not exceed 1% of the actual pressure value. It can meet the static pressure measurement requirements of non-directional two-dimensional flow fields within a large airflow angle range.

[0076] Using the non-directional two-dimensional flow field static pressure measurement probe disclosed in the above embodiments, when measuring the static pressure of the non-directional two-dimensional flow field and performing wind tunnel calibration, only one data acquisition is required at each Mach number. There is no need to adjust the probe angle for multiple data acquisitions, which has high calibration efficiency.

[0077] In the non-directional two-dimensional flow field static pressure measurement method disclosed in the above embodiments, based on the total air pressure and static pressure of the airflow, it can be considered that it is only related to the Mach number of the airflow. The calculation is performed by the ratio of the wind tunnel's true static pressure to the wind tunnel's true total pressure and the ratio of the wind tunnel's static pressure measurement value to the wind tunnel's true total pressure under different wind tunnel Mach numbers, so as to obtain the true static pressure of the non-directional two-dimensional flow field. The process is simple, can avoid the error accumulation caused by repeated iteration of multiple data, and can ensure the measurement accuracy.

[0078] In some optional embodiments, in the above-mentioned non-directional two-dimensional flow field static pressure measurement probe, the air bleed measurement end and the pressure sensor and its data acquisition system are connected by a threaded connection using a pressure cap to ensure the reliability and convenience of the connection. The air bleed measurement port and the pressure sensor and its data acquisition system are connected by a ball-head conical surface to ensure the sealing of the connection.

[0079] In some optional embodiments, the height of the three fan-shaped slits in the above-described non-directional two-dimensional flow field hydrostatic measurement probe is 1 mm.

[0080] In some optional embodiments, the above-described non-directional two-dimensional flow field hydrostatic measurement probe further includes:

[0081] Mounting seat 2 is sleeved on the outer periphery of support rod 1 and welded to support rod 1. It can be connected to the outer wall of the flow field in the form of a flange or a ball head + threaded cap, and fix support rod 1 in the flow field.

[0082] The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0083] The technical solution of this application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. A method for measuring static pressure in a non-directional two-dimensional flow field, characterized in that, Based on a non-directional two-dimensional flow field static pressure measurement probe; The non-directional two-dimensional flow field hydrostatic measurement probe includes: The support rod (1) has a pressure sensing end at one end and an air duct measurement end at the other end. The outer wall of the pressure sensing end has three fan-shaped slits; Three fan-shaped slits are distributed around the support rod (1) in the circumference, with a fan angle of 120°; The end of the air expiratory measuring device has an air expiratory hole for measurement; The measuring air vent is located on the axis of the support rod (1). The axis of the measuring air vent is perpendicular to the plane containing the three fan-shaped slits and connects the three fan-shaped slits. The non-directional two-dimensional flow field static pressure measurement method includes: Wind tunnel calibration steps: Install the non-directional two-dimensional flow field static pressure measurement probe into the wind tunnel, so that the pressure sensing end of the support rod (1) extends into the wind tunnel, and the plane of the three fan-shaped slits on the outer wall of the pressure sensing end is parallel to the wind tunnel flow field. Adjust the wind tunnel Mach number to the lower limit of the calibrated Mach number range; After the Mach number in the wind tunnel stabilizes, record the actual total pressure in the wind tunnel. Wind tunnel true static pressure And the use of pressure sensors and their data acquisition systems to collect wind tunnel static pressure measurements. ; Increase the wind tunnel Mach number and record and collect multiple sets of real total wind tunnel pressure. wind tunnel real static pressure Wind tunnel static pressure measurement values Until the wind tunnel Mach number reaches the upper limit of the calibrated Mach number range; Steps for hydrostatic measurement of non-directional two-dimensional flow field: Place the non-directional two-dimensional flow field static pressure measurement probe in the non-directional two-dimensional flow field, so that the pressure sensing end of the support rod (1) extends into the non-directional two-dimensional flow field, and the plane where the three fan-shaped slits on the outer wall of the pressure sensing end are located is in the plane of the non-directional two-dimensional flow field. The static pressure measurements of a non-directional two-dimensional flow field are acquired using a pressure sensor and its data acquisition system. ; Static pressure measurement data processing steps: Calculate the ratio of the actual static pressure to the actual total pressure in the wind tunnel at different Mach numbers. ; Calculate the ratio of the measured static pressure to the actual total pressure in the wind tunnel at different Mach numbers. ; Fitting different wind tunnel Mach numbers , ,get , The calculation relationship between them; Calculate the ratio of the static pressure measurement value to the total pressure of the non-directional two-dimensional flow field. ,in, The total pressure of the non-directional two-dimensional flow field; exist , In the calculation relationship between them, with replace Calculations yielded And then in In China, with replace , calculated As the real static pressure of a non-directional two-dimensional flow field .

2. The method for measuring static pressure in a non-directional two-dimensional flow field according to claim 1, characterized in that, In the wind tunnel calibration step, before installing the non-directional two-dimensional flow field static pressure measurement probe into the wind tunnel, the non-directional two-dimensional flow field static pressure measurement probe is inspected, including structural integrity inspection and air evacuation passage inspection. Multiple sets of actual total pressure data from the wind tunnel were collected each time. wind tunnel real static pressure Wind tunnel static pressure measurement values Before, judge , , Check for any abnormalities. If so, re-inspect the two-dimensional flow field static pressure measuring device and its related air intake pipeline. like Greater than Or different wind tunnel Mach numbers / , / If the coordinate points formed deviate from the straight line, then determine... , , Exception, otherwise check , , normal.

3. The method for measuring static pressure in a non-directional two-dimensional flow field according to claim 1, characterized in that, In the non-directional two-dimensional flow field static pressure measurement probe, the air bleed measurement end is connected to the pressure sensor and its data acquisition system by a threaded connection using a pressure cap, and the air bleed measurement hole is connected to the pressure sensor and its data acquisition system by a ball-head conical surface fit.

4. The method for measuring static pressure in a non-directional two-dimensional flow field according to claim 1, characterized in that, In the non-directional two-dimensional flow field static pressure measurement probe, the height of the three fan-shaped slits is 1 mm.

5. The method for measuring static pressure in a non-directional two-dimensional flow field according to claim 1, characterized in that, The non-directional two-dimensional flow field static pressure measurement probe also includes: Mounting seat (2) is fitted onto the outer circumference of support rod (1) and welded to support rod (1). It can be in the form of a flange or a ball head + threaded cap.

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