A five-hole probe mounting bracket

Abstract

The present invention provides a five-hole probe mounting bracket, which includes a spherical rotating mechanism, a skew angle dial, a skew angle sliding scale, a pitch angle dial and a disc structure. Among them, the skew angle sliding scale is connected to the outside of the skew angle dial and slides around the skew angle dial in the skew angle plane with the spherical rotating mechanism as the center. The pitch angle dial is connected to the outside of the skew angle sliding scale and can move together with the skew angle sliding scale. In the pitch plane, the pitch angle dial can rotate around the axis of the five-hole probe and indicate the pitch angle. The present invention mainly solves the problem of the opposite measurement of the probe in two mutually perpendicular planes, especially the rotation problem of the probe in the skew angle plane, realizes the rotation of the probe in two mutually perpendicular planes, and can be used for the opposite measurement of the five-hole probe.

Description

Technical Field

[0001] The present invention relates to the technology of probe air flow measurement, and particularly to a novel five-hole probe mounting bracket. Background Art

[0002] When conducting aerodynamic tests on the flow passage part of a turbine compressor, it is necessary to measure the air flow velocity and the air flow direction. The commonly used measuring instrument is a five-hole measuring probe.

[0003] When measuring with the existing five-hole probe, the probe is installed on a special support that can only rotate around the axis of the probe. During measurement, the probe rotates around the axis of the rod in the pitching plane. When the pressures of the two measuring holes in the pitching plane are equal, the magnitude of the air flow direction angle is read from the graduated disk; while in the skew plane perpendicular to the pitching plane, non-opposite measurement is adopted, that is, a calibration curve is generated according to the relationship between the pressure value of the pressure hole and the angle, and then the magnitude of the air flow direction angle is obtained through calculation.

[0004] Due to the limitations of the current probe mounting support, the probe can only perform opposite measurement in one plane, and the test data in the other plane can only be determined according to the calibration curve. The existing problem is: the measurement accuracy is insufficient. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a novel five-hole probe mounting bracket to solve the problem that the probe can only perform opposite measurement in one plane.

[0006] For this purpose, the present invention adopts the following technical means:

[0007] The present invention provides a five-hole probe mounting bracket, which includes a spherical rotation mechanism, and also includes a skew angle graduated disk, a skew angle sliding scale, a pitch angle graduated disk and a disk structure;

[0008] Wherein, the spherical rotation mechanism is located at the center of the disk structure;

[0009] The skew angle graduated disk is perpendicular to the plane where the disk structure is located and is connected to the disk structure;

[0010] The skew angle sliding scale is connected to the outside of the skew angle graduated disk and slides around the skew angle graduated disk in the skew angle plane with the spherical rotation mechanism as the center;

[0011] The pitch angle graduated disk is connected to the outside of the skew angle sliding scale and slides along with the skew angle sliding scale while rotating around the axis of the five-hole probe in the pitching plane.

[0012] Further, both the skew angle graduated disk and the skew angle sliding scale are arc-shaped structures, and scales are processed along the radian direction of the arc-shaped structures.

[0013] Preferably, the skew angle dial and the disc structure are processed into an integral structure.

[0014] Furthermore, the pitch angle dial is a columnar structure, with angle scales processed on the side away from the skew angle sliding scale. A through hole is processed at the center of the pitch angle dial for the five-hole probe to pass through.

[0015] Preferably, two connecting through holes are processed on the disc structure for connecting the five-hole probe mounting bracket to the outer wall of a diffuser or the like.

[0016] The present invention also proposes a five-hole probe, which is connected to the above-mentioned five-hole probe mounting bracket and sequentially passes through the center of the spherical rotating mechanism, the skew angle dial, the skew angle sliding scale, and the center of the pitch angle dial.

[0017] Compared with the prior art, the present invention has the following beneficial technical effects:

[0018] The present invention mainly solves the problem of the opposite measurement of the probe in two mutually perpendicular planes, especially the rotation problem of the probe in the skew angle plane (the maximum rotation angle is about ±30 - 35 degrees, less than the calibration angle of ±45 degrees of a general five-hole probe, which can meet the general measurement requirements). It realizes the rotation of the probe in two mutually perpendicular planes and can be used for the opposite measurement of the five-hole probe. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the mounting bracket.

[0020] Figure 2 It is the overall structure diagram of the mounting bracket.

[0021] Figure 3 It is a schematic diagram of the skew angle sliding scale.

[0022] Figure 4 It is a schematic diagram of the pitch angle scale structure.

[0023] Figure 5 It is a schematic diagram of the rotating mechanism.

[0024] Figure 6 It is a schematic diagram of the angle calculation.

[0025] Among them: 1 is the skew angle dial, 2 is the skew angle sliding scale, 3 is the pitch angle dial, 4 is the spherical rotating mechanism, 5 is the disc structure, 6 is the connecting through hole, and 7 is the five-hole probe.

[0026] The following further illustrates the solution of the present invention in conjunction with the drawings and embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0027] To make the solution of the present invention clearer, it should be noted that the skew angle described in the present invention is defined as the inclination angle between the center line of the central hole 2 of the five-hole probe and the air flow direction on the horizontal plane. When the axis of the five-hole probe is perpendicular to the air flow direction, the skew angle is zero. At the same time, the pitch angle described in the present invention is relative to the aforementioned horizontal plane and is the rotation angle of the five-hole probe within the plane perpendicular to this horizontal plane.

[0028] Two symmetric connecting through holes are machined on the disc, which are connecting holes for connecting the mounting bracket to the outer wall of the diffuser and the like.

[0029] The five-hole probe of the present invention passes through the center of the spherical rotating mechanism and is connected to the spherical rotating mechanism. The connection between the five-hole probe and the spherical rotating mechanism is an existing structure, and the principle is the same as the working principle of the manual or automatic gear shift lever of an automobile. By switching the shift fork, the mechanical switching of the gearbox can be realized. When applied to the present invention, it can make the five-hole probe freely change the stroke direction and stroke value.

[0030] The connection method of the skew angle dial and the skew angle sliding scale in the present invention is relatively conventional. For example, a slot is machined along the arc direction on the skew angle dial, and a block is provided on the skew angle sliding scale. By moving the block in the slot, the movement of the skew angle sliding scale along the skew angle dial can be realized.

[0031] Regarding this, the present invention

[0032] makes no limitation.

[0033] Embodiment 1:

[0034] This embodiment provides a five-hole probe mounting bracket, which includes a spherical rotating mechanism 4, and is characterized in that it further includes a skew angle dial 1, a skew angle sliding scale 2, a pitch angle dial 3 and a disc structure 5;

[0035] Among them, the spherical rotating mechanism 4 is located at the center of the disc structure 5 and provides movable support for the pitch angle dial 3.

[0036] The skew angle dial 1 is perpendicular to the plane where the disc structure 5 is located and is connected to the disc structure 5. The skew angle sliding scale 2 is connected to the outside of the skew angle dial 1 and slides around the skew angle dial 1 in the skew angle plane with the spherical rotating mechanism 4 as the center to realize the measurement of the skew angle plane.

[0037] The pitch angle dial 3 is connected to the outside of the skew angle sliding scale 2 and slides along with the skew angle sliding scale 2 while rotating around the axis of the five-hole probe in the pitch plane.

[0038] The skew angle dial 1 and the skew angle sliding scale 2 are both arc-shaped structures, and scales are machined along the radian direction of the arc-shaped structure. The skew angle dial 1 and the disc structure 5 are machined into an integral structure.

[0039] The pitch angle dial 3 is a columnar structure, and angle scales are machined on the side away from the skew angle sliding scale 2. A through hole is machined at the center of the pitch angle dial 3 for the five-hole probe to pass through.

[0040] Two connecting through holes are machined on the disc structure 5 for connecting the five-hole probe mounting bracket to the outer wall of a diffuser or the like, facilitating the implementation of measurement.

[0041] 1. The structure of the present invention, and its basic measurement principle is:

[0042] The skew angle sliding scale 2 rotates around the skew angle dial 1 with the spherical rotation 4 mechanism as the center and indicates the scale value (in the skew angle plane, since the probe ball center does not coincide with its rotation center, the measured angle value needs to be simply calculated to obtain the actual air flow direction angle value. The calculation method is shown in the following calculation method section); the pitch angle dial 3 is connected to the skew angle sliding scale 2, and can rotate around the probe axis in the pitch plane, and at the same time slide in the skew angle plane following the skew angle sliding scale 2, and indicate the angle of the probe rotating in the pitch plane.

[0043] 2. Taking the measurement of the air flow velocity and air flow direction at the outlet of a certain diffuser as an example, the structure of the present invention, its basic measurement method or usage method is described in detail:

[0044] 1). Through the holes on the end face of the disc 5, fix the probe mounting bracket on the partition where measurement needs to be carried out (the partition has reserved an installation position, and the installation screw holes are shown in the appendix Figure 4 ), and then install the five-hole probe.

[0045] 2). In the pitch plane, use a level to adjust the orientation block at the tail of the probe; in the skew plane, with the end face of the disc structure as the reference, use an angle gauge to adjust the installation angle between the probe rod and the disc structure, so that the probe coincides with the state during calibration, and record the readings of the skew angle and pitch angle at this time.

[0046] 3). According to the design value, roughly adjust the skew angle and pitch angle of the probe. When the device to be tested reaches the pre-test state, adjust the skew scale so that the values indicated by the pressure indicators connected to the five-hole needles (4*, 5*) are equal, and fix the skew sliding scale; then adjust the pitch angle dial so that the values indicated by the pressure indicators connected to the five-hole needles (1*, 3*) are equal, and fix the pitch angle dial, and finally record the data.

[0047] 4) Change the test state of the device under test, adjust the skew sliding scale to make the values indicated by the pressure indicators connected to the five-hole needles (4*, 5*) equal again, and fix the skew sliding scale; then adjust the pitch angle dial to make the values indicated by the pressure indicators connected to the five-hole needles (1*, 3*) equal again, and fix the pitch angle dial. Finally, record the data.

[0048] 5) Compare the scale readings of the skew angle and pitch angle in Step 3 with those in Step 4 respectively. The difference is the change amount of the air flow direction under two different test states. (Note: The data in the skew angle plane cannot be directly read and need to be simply calculated. For details, see the calculation method and principle of the skew angle reading.)

[0049] As Figure 1 , when measuring in the opposite direction in the skew angle plane, when the pressures indicated by the five-hole needles (4*, 5*) are equal, at this time, the air flow direction is consistent with the axis of the central hole. Read and record the scale on the skew angle dial 1 (the angle value of the air flow direction in the skew angle can be calculated according to the calculation formula).

[0050] In the pitch angle plane, when the pressures indicated by the five-hole needles (1*, 3*) are equal, directly read the angle value of the air flow direction of the pitch angle from the pitch angle dial 3.

[0051] 3. In the skew angle plane, the method for indirectly converting and calculating the air flow direction angle ∠D by applying the structure of the present invention is as follows:

[0052] In the skew angle plane, since the center of the probe tip sphere does not coincide with the probe rotation center (the center of the spherical rotation mechanism), the measured angle value needs to be calculated. The calculation principle and schematic diagram are as shown in the appendix Figure 6 :

[0053] ∠D = ∠b - (180 - ∠C) / 2;

[0054] Among them, ∠b is the included angle between the aerodynamic axis and the probe rod center line in the corrected skew angle plane;

[0055] The value of ∠C is the reading of the skew angle sliding scale 2; ∠D is the air flow direction angle to be finally calculated.

[0056] It should be noted that due to the manufacturing deviation of the probe, the aerodynamic axis of the probe is often inconsistent with the geometric axis of the probe. Before using the probe, it is necessary to calibrate the geometric and aerodynamic axes of the probe on the air duct to determine the correction angle between them. The general angle of ∠b is 90°. Due to the machining manufacturing error, it is necessary to perform air duct calibration before use, so there may be an error of less than 3°. Calculate based on the on-site calibration.

[0057] To further optimize this solution, a gasket is added between the probe mounting support and the mounting base, and then tightened with screws (see attachment Figure 1 ). A sealing ring is provided between the probe and the spherical rotating mechanism for sealing, and no leakage will occur.

Claims

1. A five-hole probe mounting bracket, comprising a spherical rotating mechanism (4), and the five-hole probe passes through the center of the spherical rotating mechanism (4) and is connected to the spherical rotating mechanism (4). It is characterized in that it further comprises a yaw angle dial (1), a yaw angle sliding scale (2), a pitch angle dial (3) and a disc structure (5); wherein, the spherical rotating mechanism (4) is located at the center of the disc structure (5); the yaw angle dial (1) is perpendicular to the plane where the disc structure (5) is located and is connected to the disc structure (5); the yaw angle sliding scale (2) is connected to the outside of the yaw angle dial (1) and slides around the yaw angle dial (1) in the yaw angle plane with the spherical rotating mechanism (4) as the center; the pitch angle dial (3) is connected to the outside of the yaw angle sliding scale (2) and can slide along with the yaw angle sliding scale (2) while rotating around the axis of the five-hole probe in the pitch plane; both the yaw angle dial (1) and the yaw angle sliding scale (2) are arc-shaped structures, and scales are processed along the radian direction of the arc-shaped structures; the yaw angle dial (1) and the disc structure (5) are processed into an integral structure; the pitch angle dial (3) is a columnar structure, angle scales are processed on the surface far from the yaw angle sliding scale (2), and a through hole is processed at the center of the pitch angle dial (3) for the five-hole probe to pass through; two connecting through holes (6) are processed on the disc structure (5) for connecting the five-hole probe mounting bracket to the outer wall of the diffuser; a five-hole probe is connected to the five-hole probe mounting bracket, and the five-hole probe sequentially passes through the center of the spherical rotating mechanism (4), the yaw angle dial (1), the yaw angle sliding scale (2) and the center of the pitch angle dial (3); When the five-hole probe mounting bracket is applied in the yaw angle plane, the following formula is used for calculation: ∠D = ∠b - (180° - ∠C) / 2; In the formula: ∠D is the airflow direction angle to be finally calculated; ∠b is the included angle between the aerodynamic axis and the probe rod center line in the corrected yaw angle plane; The value of ∠C is the reading of the yaw angle sliding scale.

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