CN106950005B - A Cylindrical Eight-hole Pressure Probe for Measuring Two-Dimensional Flow Parameters in Arbitrary Directions - Google Patents

Abstract

The invention belongs to the technical field of pressure testing, and discloses a cylindrical eight-hole pressure probe for measuring two-dimensional flow parameters flowing in any direction, comprising a probe head and a support rod. There are 8 pressure-sensing holes that do not communicate with each other evenly along the circumferential direction on the surface. The center lines of these 8 holes are on the same plane, and the plane is perpendicular to the axis of the cylinder of the probe head. The 8 pressure-inducing tubes encapsulated in the probe head are connected, and the pressure-inducing tubes lead out the probe tail through the inner channel of the probe support rod. Compared with the existing pressure probe, the invention can simultaneously measure the total pressure, static pressure, Mach number and flow direction of the incoming flow in any direction in the plane where the eight pressure sensing holes are located, and is suitable for measuring the air flow. There is a two-dimensional complex flow field with backflow at the inlet, outlet and between stages of the blade row during the surge of the engine, compressor, fan, etc.

Description

A Cylindrical Eight-hole Pressure Probe for Measuring Two-Dimensional Flow Parameters in Arbitrary Directions

technical field

The invention belongs to the technical field of pressure testing, relates to a pressure measuring device for a two-dimensional flow field, and in particular relates to a cylindrical eight-hole pressure probe for measuring two-dimensional flow parameters of flow in any direction, which is suitable for measuring aero-engines, compressors, fans, etc. There is a two-dimensional complex flow field of backflow at the inlet, outlet and between stages of the blade row during the surge.

Background technique

Pressure probes, such as three-hole pressure probes, five-hole pressure probes, seven-hole pressure probes, etc., are widely used in aero-engines, gas turbines, compressors, fans, pumps due to their simple structure, robustness and durability, and easy operation. Intra-flow field measurements. Three-hole pressure probes are used to measure two-dimensional flow parameters, and five-hole pressure probes and seven-hole pressure probes are used to measure three-dimensional flow parameters. However, the range of the three-hole pressure probe and the five-hole pressure probe to measure the flow direction is limited, generally not exceeding ±45°. The range of the incoming flow angle measured by the seven-hole pressure probe is generally not more than ±70°.

When measuring a flow field with an unknown incoming flow direction, if these probes are not installed roughly aligned with the incoming flow direction, which exceeds the effective angle measurement range of the probe, then although the data is obtained from the pressure sensing hole measurement, the flow rate cannot be calculated. Flow parameters such as direction, total pressure, static pressure, etc.

When there is backflow in the measured flow field, the commonly used three-hole pressure probe, five-hole pressure probe or seven-hole pressure probe cannot complete accurate measurement, especially for aero-engines, gas turbines, compressors, fans, compressors, turbines The measurement of complex internal flow fields such as fans, pumps, etc. lacks engineering and practical pressure probe technology that can take into account the measurement of backflow.

SUMMARY OF THE INVENTION

The main technical problem solved by the present invention is: for the measurement of complex internal flow fields such as aero-engines, gas turbines, compressors, turbines, fans, pumps, etc., there is a lack of engineering and practical pressure probe technology that can take into account the measurement of backflow. The cylindrical eight-hole pressure probe with two-dimensional flow parameters in the direction of the incoming flow can measure the deflection angle of the two-dimensional complex flow field that exists in the inlet, outlet, and interstage of the blade discharge during the surge of aero-engines, compressors, fans, etc. Total pressure, static pressure, Mach number.

In order to solve the above-mentioned technical problems, the technical scheme adopted in the present invention is:

1. A cylindrical eight-hole pressure probe for measuring two-dimensional flow parameters in any direction, characterized in that it comprises a probe head (1), a support rod (2), and the probe head (1) is The cylindrical structure has 8 pressure-sensing holes (3) that do not communicate with each other uniformly on its cylindrical surface along the circumferential direction, and the centerline angle of the two adjacent pressure-sensing holes (3) is 45°. The center line of the pressure sensing holes (3) is on the same plane, and the plane is perpendicular to the cylinder axis of the probe head (1). One end in the head (1) is communicated with each other.

2. Further, the probe support rod (2) is a cylindrical body, and a circular channel is opened inside the probe head (1). , drawn from the probe tail.

3. Further, the plane where the centers of the eight pressure sensing holes (3) of the probe head (1) are located is not less than 1 mm away from the top surface (5) of the probe head (1).

4. Further, the diameter of the eight pressure sensing holes (3) of the probe head (1) is 0.2 mm to 1 mm.

5. Further, the probe head (1) has a diameter of 4 mm to 8 mm and a length of 10 mm to 50 mm.

The beneficial effects of the present invention are:

After calibration experiments, the invention obtains the data of eight pressure sensing holes of a cylindrical eight-hole pressure probe under different flow directions under the conditions of known total incoming pressure, static pressure and incoming flow direction, and sorts out the total pressure characteristics. , three curves of static pressure characteristics and deflection angle characteristics. During the actual measurement, the cylindrical eight-hole pressure probe measures the pressure data felt by the eight pressure sensing holes. According to the three characteristic curves of the cylindrical eight-hole pressure probe, the total pressure, static pressure and Mach of the measured flow field are obtained by conversion. and deflection angle data.

Compared with the prior art, the cylindrical eight-hole pressure probe of the present invention can achieve the following technical effects:

1. After the probe is installed, there is no need to adjust the probe installation angle during measurement.

2. It can measure the flow direction is unknown, the flow direction changes greatly, the installation angle cannot be adjusted after the probe is installed, the inflow deflection angle, total pressure, static pressure and Mach number in the presence of backflow.

It can be applied to the measurement of two-dimensional complex flow fields with backflow at the inlet, outlet, and stages of the blade row during the surge process of aero-engines, compressors, and fans.

Description of drawings

FIG. 1 is a schematic structural diagram of a cylindrical eight-hole pressure probe for measuring two-dimensional flow parameters flowing in any direction in an embodiment of the present invention.

Among them: 1-probe head, 2-probe support, 3-pressure sensing hole, 4-pressure tube, 5-top surface.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

As shown in Figure 1, this embodiment introduces a cylindrical eight-hole pressure probe for measuring two-dimensional flow parameters in any direction, including a probe head (1), a support rod (2), a probe head (1) It is a cylindrical structure, and eight pressure sensing holes (3) that do not communicate with each other are uniformly opened on the cylindrical surface along the circumferential direction, and the angle between the center lines of the two adjacent pressure sensing holes (3) is 45° , the center lines of the 8 pressure sensing holes (3) are on the same plane, which is perpendicular to the cylinder axis of the probe head (1), and the 8 pressure sensing holes (3) are connected to the 8 pressure tubes (4) One end encapsulated in the probe head (1) is connected to each other.

The probe support rod (2) is a cylinder with a diameter of 6 mm, and a circular channel is opened inside with a diameter of 4 mm. The eight pressure-inducing tubes (4) enclosed in the probe head (1) pass through the probe support rod ( 2) Inner channel, led out from the probe tail.

The plane where the circle centers of the eight pressure sensing holes (3) of the probe head (1) are located is 2 mm away from the top surface (5) of the probe head (1).

The diameter of the eight pressure-sensing holes (3) of the probe head (1) is 0.4 mm.

The probe head (1) has a diameter of 4 mm and a length of 40 mm.

After calibration experiments, the invention obtains the data of eight pressure sensing holes of a cylindrical eight-hole pressure probe under different flow directions under the conditions of known total incoming pressure, static pressure and incoming flow direction, and sorts out the total pressure characteristics. , three curves of static pressure characteristics and deflection angle characteristics. During the actual measurement, the cylindrical eight-hole pressure probe measures the pressure data felt by the eight pressure sensing holes. According to the three characteristic curves of the cylindrical eight-hole pressure probe, the total pressure, static pressure and Mach of the measured flow field are obtained by conversion. and deflection angle data. It can measure the deflection angle, total pressure, static pressure and Mach number of the two-dimensional complex flow field in the inlet, outlet and interstage of the blade row during the surge of aero-engines, compressors, fans, etc. It is also suitable for measuring incoming flow. The direction is unknown, the direction of the incoming flow changes greatly, the installation angle cannot be adjusted after the probe is installed, and there is a two-dimensional complex flow field with backflow.

Claims (1)

1. The utility model provides a measure eight hole pressure probes of cylinder of arbitrary direction incoming flow two-dimensional flow parameter which characterized in that: the probe comprises a probe head (1) and a supporting rod (2), wherein the probe head (1) is of a cylindrical structure, 8 pressure sensing holes (3) which are not communicated with each other are uniformly formed in the cylindrical surface of the probe along the circumferential direction, the included angle of the central lines of the adjacent 2 pressure sensing holes (3) is 45 degrees, the central lines of the 8 pressure sensing holes (3) are in the same plane, the plane is vertical to the cylindrical axis of the probe head (1), and the 8 pressure sensing holes (3) are respectively communicated with one end of 8 pressure guide pipes (4) which are packaged in the probe head (1);

the probe supporting rod (2) is a cylinder, a circular channel is formed in the probe supporting rod, and 8 pressure leading pipes (4) packaged in the head (1) of the probe are led out from the tail of the probe through the channel in the probe supporting rod (2);

the distance between the plane where the circle centers of the 8 pressure sensing holes (3) of the probe head (1) are located and the top surface (5) of the probe head (1) is not less than 1 mm;

the diameters of 8 pressure sensing holes (3) of the probe head (1) are 0.4 mm;

the probe head (1) has a diameter of 4 mm and a length of 40 mm.