阅读说明：本技术 一种测量转静间端区二次流的小扰动高分辨率动态探针 (Small-disturbance high-resolution dynamic probe for measuring secondary flow in static and rotating middle end region ) 是由 马宏伟 谢忠强 钟亚飞 于 2021-07-22 设计创作，主要内容包括：本发明属于亚音速三维流场参数测试技术领域,具体涉及一种测量转静间端区二次流的小扰动高分辨率动态探针。包括探针头部、支杆、动态压力传感器、定位块,探针头部包括共底面的圆柱体和双扭线旋成体,其内部封装2个动态压力传感器,在探针头部双扭线旋成体侧面和同一侧的圆柱体侧面,各开有一个压力感受孔,分别与探针头部内封装的动态压力传感器连通,传感器线缆通过探针支杆内通道引出探针尾部,探针尾部套装一个定位块。本发明经过校准风洞标定,可以测量叶轮机转静间端区二次流三维流场参数的动态变化,流场参数包括气流俯仰角、气流偏转角、总压、静压和马赫数,为提高叶轮机性能提供实测数据依据。与其它测量亚音速三维流场双孔动态压力探针相比,本发明自带定位功能,探针头部采用双扭线旋成体结构,压力感受孔圆心与探针头部最低点的垂直距离小,斜孔圆心和正孔圆心之间的距离小,具有对端区流场干扰小、空间分辨率较高、频响高、可精确测量叶轮机转静间端区二次流气流俯仰角、气流偏转角、总压、静压和马赫数的动态变化的优点。(The invention belongs to the technical field of subsonic three-dimensional flow field parameter testing, and particularly relates to a small-disturbance high-resolution dynamic probe for measuring secondary flow in a rotating-static middle terminal area. The probe comprises a probe head, a supporting rod, dynamic pressure sensors and a positioning block, wherein the probe head comprises a cylinder and a double-twisted-line rotating body which are arranged on the same bottom surface, 2 dynamic pressure sensors are packaged in the probe head, the side surfaces of the double-twisted-line rotating body on the probe head and the side surface of the cylinder on the same side are respectively provided with a pressure sensing hole which is respectively communicated with the dynamic pressure sensors packaged in the probe head, a sensor cable leads out a probe tail through a channel in the probe supporting rod, and the probe tail is sleeved with the positioning block. The method can measure the dynamic change of the secondary flow three-dimensional flow field parameters at the rotating and static middle end area of the turbine through calibration of the wind tunnel, wherein the flow field parameters comprise an airflow pitch angle, an airflow deflection angle, total pressure, static pressure and Mach number, and provide an actual measurement data basis for improving the performance of the turbine. Compared with other double-hole dynamic pressure probes for measuring subsonic three-dimensional flow fields, the double-hole dynamic pressure probe has a positioning function, the head of the probe adopts a double-twisted-line rotating body structure, the vertical distance between the center of a pressure sensing hole and the lowest point of the head of the probe is small, and the distance between the center of an inclined hole and the center of a positive hole is small.)

1. The utility model provides a measure and change quiet interzone secondary flow's small perturbation high resolution dynamic probe, by probe head (1), branch (2), dynamic pressure sensor (7), locating piece (9) constitute, its characterized in that: the probe head (1) is composed of a cylinder (3) and a double-twisted-wire rotating body (4) which share the same bottom surface, the joint of the cylinder (3) and the double-twisted-wire rotating body (4) is in smooth curved surface transition, and 2 dynamic pressure sensors (7) are packaged in the probe head (1); a pressure sensing hole which is an inclined hole (5) is formed in the side face of the double-twisted-wire rotating body (4), and the inclined hole (5) is communicated with a dynamic pressure sensor (7) packaged in the probe head (1); another pressure sensing hole is formed in the side face of the cylinder (3) on the same side of the double-twisted-line rotating body (4) where the inclined hole (5) is located, the other pressure sensing hole is a positive hole (6), and the positive hole (6) is communicated with another dynamic pressure sensor (7) which is packaged; the central line of the inclined hole (5) and the central line of the positive hole (6) are on the same plane with the axis of the cylinder (3) of the probe head (1); the axis of the cylinder (3) of the probe head (1) is superposed with the axis of the probe supporting rod (2);

the diameter of the cylinder (3) of the probe head (1) is d, the range of d is more than or equal to 2.5 mm and less than or equal to 3.6 mm, and the length is 4d to 8 d;

the rotating body (4) is formed by rotating an AB curve section on a lemniscate around a shaft L, a point A is a lemniscate intersection point, a tangent of a point B is vertical to a tangent of the point A, and a rotating shaft L passes through the point A and is vertical to the tangent of the point A;

the diameter of the inclined hole (5) is 0.2 mm to 0.4 mm, the included angle between the central line of the inclined hole (5) and the axial line of the cylinder (3) of the probe head (1) is theta, and the value range is that theta is more than or equal to 0 degree and less than 90 degrees;

the vertical distance between the center of the inclined hole (5) and the lowest point of the surface of the twisted pair body (4) is h1, and the value range is that h1 is more than or equal to 0d and less than 0.29 d;

the diameter of the main hole (6) is 0.2 mm to 0.4 mm, the vertical distance between the circle center of the main hole (5) and the lowest point of the surface of the rotating body (4) is h2, and the value range of h2 is more than or equal to 0.29d and less than or equal to 0.6 d;

the probe supporting rod (2) is a cylinder, the diameter of the probe supporting rod is D, the value range of D is more than or equal to 6 mm and less than or equal to 10 mm, a circular pipeline is arranged in the probe supporting rod, a cable (8) of a dynamic pressure sensor packaged in the head part (1) of the probe is led out of the tail part of the probe through the pipeline in the probe supporting rod (2), and a positioning block (8) is sleeved on the tail part of the probe;

the positioning block (9) is of an integrated structure and comprises a cuboid base (10), a cylindrical boss (11), a through hole (12) and threaded holes (13), the through hole (12) is sleeved at the tail of the probe, a countersunk screw (14) penetrates through the threaded holes (13) on the two sides of the boss (11) to be fixed, and the countersunk screw (14) is completely embedded into the threaded holes (13);

the rectangular base (10) comprises four rectangular side surfaces and two square bottom surfaces, two adjacent side surfaces in the four side surfaces are perpendicular to each other, the four side surfaces can be used as positioning surfaces, one bottom surface in the base (10) is connected with a cylindrical boss (11), a perpendicular bisector of the bottom surface is superposed with the axis of the boss (11), the axis of the boss (11) is superposed with the central line of a through hole (12), the diameter of the through hole is D +0.05 mm, the outer diameter of the boss (11) is M, the value range of D +2 mm is not less than M and not more than D +5 mm, the side length of the bottom surface of the base (10) is M to M +3 mm, the thickness of the base (10) is H, and the value range of 2 mm is not less than H and not more than 5 mm;

calibrating the probe in a subsonic calibration wind tunnel, selecting one side surface of a base (10) of a positioning block (9) as a positioning surface, determining the relative position of the positioning surface of the positioning block (9) and a front hole (6) through a level gauge, fixing the positioning block (9) through a countersunk head screw (14), and obtaining the pneumatic calibration coefficient of the probe in different incoming flow directions and different Mach numbers;

in actual measurement, a probe is installed and fixed on a displacement mechanism, the specific process is that a level gauge is utilized to adjust the level of a positioning surface of the displacement mechanism, the probe is installed on the displacement mechanism, the level gauge is placed on the positioning surface of a probe positioning block (9), the probe is rotated along the axis of a probe supporting rod (2), the level of the positioning surface is adjusted through the level gauge, the relative position of the central line of a front hole (6) and the positioning surface of the displacement mechanism is determined, and the probe is fixed on the displacement mechanism; the displacement mechanism for installing the probe is installed on a turbine casing (15) to be measured through a positioning device, the displacement mechanism is adjusted to enable a certain radial position of a flow field in an insertion end region of the probe to be aligned to the average incoming flow direction, the probe is adjusted through the displacement mechanism according to the known average incoming flow direction, a positive hole (6) is aligned to the average incoming flow direction, the position is taken as a reference, the displacement mechanism is utilized to drive the probe to rotate 1 angle around the axis of a probe supporting rod (2) in the anticlockwise direction and the clockwise direction respectively, the rotation angle is 30-45 degrees, 3 angle positions are measured in total, and the pneumatic calibration coefficients of the probe in different incoming flow directions and different Mach numbers obtained by a subsonic calibration wind tunnel are combined under each angle position to calculate the airflow pitch angle, the airflow, the total pressure deflection angle, the static pressure and the Mach number of the measured flow field;

compared with other double-hole dynamic pressure probes, the double-hole dynamic pressure probe has the beneficial effects that:

(1) the probe head adopts a double-twisted-wire rotating body structure, the vertical distance between the centers of the two pressure sensing holes and the lowest point of the surface of the double-twisted-wire rotating body is smaller, and the dynamic parameters of the secondary flow field of an end region closer to the wall surface can be measured;

(2) the double-twisted-line rotating body is in smooth curved surface transition with the cylinder at the head of the probe, when airflow flows through the surface of the double-twisted-line rotating body, the special structure of the double-twisted-line rotating body can inhibit the airflow separation of the airflow on the surface of the double-twisted-line rotating body and weaken the interference of the streaming around the head of the supporting rod on the flow field of a measured area, and on the other hand, when the flow field parameter is measured close to the end wall, the invention can inhibit the scale of the horseshoe vortex at the front end of the head of the probe and reduce the measurement error;

(3) the rotary body is flat, the structure enables the distance between the circle center of the inclined hole and the circle center of the main hole to be closer to each other on one hand, and the space resolution of the probe is improved, and on the other hand, the dynamic pressure sensor communicated with the inclined hole can be installed closer to the inclined hole, so that the volume of an accommodating cavity between the inclined hole and the sensor is greatly reduced, the effect of the accommodating cavity is reduced, and the frequency response of the probe is improved;

(4) the probe head has relatively small size, can be inserted into the dynamic change of secondary flow field parameters of a turbine rotor-stator measurement end region, and has small interference on a measured flow field;

(5) the positioning block adopted by the invention has small size, the influence on the probe is small in the measuring process, and because four side surfaces of the positioning block can be used as positioning surfaces and can be replaced mutually, the positioning process is simple and convenient, and the positioning method is more suitable for practical engineering application.

Technical Field

The invention belongs to the technical field of subsonic three-dimensional flow field parameter testing, and particularly relates to a small-disturbance high-resolution dynamic probe for measuring secondary flow in a rotating and static terminal area, which is suitable for measuring dynamic change of secondary flow field parameters in the terminal area between a rotor and a stator of a turbine, wherein the flow field parameters comprise an air flow pitch angle, an air flow deflection angle, total pressure, static pressure and Mach number.

Background

The method has the advantages that secondary flow field parameters of rotating and static intermediate end regions of the impellers such as a fan, a gas compressor, a turbine, a pump, a fan, a compressor and the like are obtained, and the method has an important effect on improving the performance of the impellers. The turbine rotating and static intermediate region comprises a blade tip region and a blade root angle region, and for the test of three-dimensional flow field parameters in the turbine rotating and static intermediate blade tip region and the blade root angle region, the flow field has strong non-stationarity and rotation property because the flow field comprises a movable blade wake, a leakage vortex, an angle vortex and other secondary flows, and the axial gap between the turbine rotating and static intermediate region is very small, especially the axial gap between the turbine rotating and static intermediate region is smaller in a small and medium-sized turbine, so that the test of the three-dimensional flow field parameters in the secondary flows in the turbine rotating and static intermediate region has the measurement difficulties of large airflow pitch angle, large airflow deflection angle, narrow measurement space and the like.

The conventional steady-state pressure probe can only obtain the steady-state value of the flow field parameter and cannot obtain the dynamic change of the flow field parameter; the hot wire probe can measure a dynamic velocity signal of a flow field, but cannot provide dynamic information of an airflow pitch angle, an airflow deflection angle, total pressure, static pressure and Mach number. In a turbine test, dynamic changes of a pitch angle, an airflow deflection angle, total pressure, static pressure and a Mach number of a secondary flow field in a rotating and static intermediate end region are preferably obtained by measuring parameters of the secondary flow field in the rotating and static intermediate end region, and the dynamic changes are used for verifying turbine design and flow field diagnosis so as to improve the performance of a turbine, and the probe cannot meet the current test requirements.

Currently, a single-hole/multi-hole dynamic pressure probe is generally adopted for measuring dynamic parameters of a subsonic three-dimensional flow field. When the single-hole dynamic pressure probe is used for measuring dynamic parameters of a three-dimensional flow field, the single-hole dynamic pressure probe needs to rotate by 7 angles along the axis of the supporting rod, and difficulty is increased for test operation and subsequent data processing. When the porous dynamic pressure probe is used for measuring dynamic parameters of a three-dimensional flow field, the porous dynamic pressure probe usually rotates for 3 angles along the axis of the support rod, and test operation and data processing are relatively simple. The existing three-dimensional porous dynamic pressure probe mainly comprises a double-hole, 4-hole, 5-hole and 7-hole dynamic pressure probe, because the number of pressure sensing holes is consistent with that of dynamic pressure sensors packaged in the head of the probe, when the number of the pressure sensing holes is more than or equal to 4, the number of corresponding sensors is large, on one hand, the manufacturing cost of the probe is increased, on the other hand, the size of the head of the dynamic pressure probe is limited by the size of the sensors, and the probe cannot be inserted into a rotating chamber of a small-sized turbine to perform testing. In addition, the large size of the head part can reduce the spatial resolution of the probe, reduce the measurement precision and seriously interfere the measured flow field. The double-hole dynamic pressure probe has the potential of measuring three-dimensional flow field dynamic parameters of a rotating static space of a small and medium-sized turbine due to the small number of sensors and the small size of the head of the probe, and patent 201710118829.5 introduces a conical double-hole dynamic pressure probe for measuring cross-tone three-dimensional flow at the outlet of a rotor, wherein the head of the probe is a cylinder and a cone with the same bottom surface; patent 201710126245.2 discloses a cylindrical double-hole dynamic pressure probe for measuring subsonic three-dimensional flow at the outlet of a rotor, wherein the head of the probe is a cylinder with a common bottom surface and a cylindrical chamfer. The joints of the heads of the two probes are not in smooth curved surface transition, and when the flow angle of incoming flow is large, the flow is easy to separate near the heads of the probes, so that the measured flow field is seriously disturbed; when the probe is used for measuring dynamic parameters of a three-dimensional flow field in an end region, horseshoe vortexes can be generated when incoming flow bypasses a cylinder, and the horseshoe vortexes can reduce the test precision of the probe; in addition, the tip spaces of the cone and the cylindrical beveling body are small, and the dynamic pressure sensor cannot be installed close to the pressure sensing hole, so that a cavity from the pressure sensing hole to the sensor is large, the cavity effect is obvious, and the frequency response of the probe is low; the size of the probe head is large, the distance between the centers of the two pressure sensing holes is long, and the spatial resolution of the probe is low. Therefore, the two three-dimensional double-hole dynamic pressure probes are not ideal for measuring the secondary flow field parameters in the rotating and static tail regions of the turbine, and the two probes are not claimed to be related to the positioning block.

There are few descriptions about probe positioning blocks, for example, patent 201710200518.3 describes a pressure probe positioning block, in which a bubble level is sleeved on one side of the base of the positioning block, and the positioning block has the disadvantages of large size, single positioning surface, etc. Therefore, in order to measure the dynamic changes of the airflow pitch angle, the airflow deflection angle, the total pressure, the static pressure and the mach number of the secondary flow field at the rotating and static tail end region of the turbine, the development of a small-disturbance high-resolution dynamic probe with a positioning function is urgently needed.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: and measuring dynamic changes of an airflow pitch angle, an airflow deflection angle, total pressure, static pressure and Mach number in a secondary flow field at a subsonic rotating and static middle end region. Therefore, the invention provides a small-disturbance high-resolution dynamic probe for measuring secondary flow in a static and rotating middle region. Compared with other double-hole dynamic pressure probes for measuring three-dimensional flow fields of turbine engines, the double-hole dynamic pressure probe has a positioning function, the head of the probe adopts a double-twisted-line rotating body structure, the vertical distance between the center of a pressure sensing hole and the lowest point of the head of the probe is small, and the distance between the center of an inclined hole and the center of a positive hole is small, so that the double-twisted-line rotating body has the advantages of small interference on the flow field of an end area, high spatial resolution, high frequency response and capability of accurately measuring the dynamic changes of the pitch angle, the deflection angle, the total pressure, the static pressure and the Mach number of secondary flow in the end area. The invention is suitable for measuring the dynamic changes of the airflow pitch angle, the airflow deflection angle, the total pressure, the static pressure and the Mach number in the secondary flow field at the rotating and static tail end area of the turbine.

The technical solution of the invention is as follows:

1. the utility model provides a measure and change quiet interzone secondary flow's small perturbation high resolution dynamic probe, by probe head (1), branch (2), dynamic pressure sensor (7), locating piece (9) constitute, its characterized in that: the probe head (1) is a cylinder (3) and a double-twisted-wire spinning body (4) which share the same bottom surface, the joint of the cylinder (3) and the double-twisted-wire spinning body (4) is in smooth curved surface transition, and 2 dynamic pressure sensors (7) are packaged in the probe head (1); a pressure sensing hole which is an inclined hole (5) is formed in the side face of the double-twisted-wire rotating body (4), and the inclined hole (5) is communicated with a dynamic pressure sensor (7) packaged in the probe head (1); another pressure sensing hole is formed in the side face of the cylinder (3) on the same side of the double-twisted-line rotating body (4) where the inclined hole (5) is located, the other pressure sensing hole is a positive hole (6), and the positive hole (6) is communicated with another dynamic pressure sensor (7) which is packaged; the central line of the inclined hole (5) and the central line of the positive hole (6) are on the same plane with the axis of the cylinder (3) of the probe head (1); the axis of the cylinder (3) of the probe head (1) is coincided with the axis of the probe supporting rod (2).

2. Furthermore, the diameter of the cylinder (3) at the head part (1) of the probe is d, the range of d is more than or equal to 2.5 mm and less than or equal to 3.6 mm, and the length is 4d to 8 d.

3. Further, the rotating body (4) is formed by rotating an AB curve section on a lemniscate around a shaft L, a point A is an intersection point of the lemniscate, a tangent of a point B is perpendicular to a tangent of the point A, and the rotating shaft L passes through the point A and is perpendicular to the tangent of the point A.

4. Furthermore, the diameter of the inclined hole (5) is 0.2 mm to 0.4 mm, the included angle between the central line of the inclined hole (5) and the axial line of the cylinder (3) of the probe head (1) is theta, and the value range is that theta is more than or equal to 0 degrees and less than 90 degrees.

5. Furthermore, the vertical distance between the center of the inclined hole (5) and the lowest point of the surface of the twisted pair body (4) is h1, and the value range is that h is more than or equal to 0d and less than 0.29 d.

6. Furthermore, the diameter of the main hole (6) is 0.2 mm to 0.4 mm, the vertical distance between the center of the main hole (5) and the lowest point of the surface of the rotating body (4) is h2, and the value range is that h2 is not less than 0.29d and not more than 0.6 d.

7. Furthermore, the probe supporting rod (2) is a cylinder, the diameter of the probe supporting rod is D, the value range of D is more than or equal to 4 mm and less than or equal to 10 mm, a circular pipeline is arranged in the probe supporting rod, a cable (8) of the dynamic pressure sensor packaged in the probe head part (1) is led out of the probe tail part through the pipeline in the probe supporting rod (2), and the probe tail part is sleeved with a positioning block (9).

8. Furthermore, locating piece (9) structure as an organic whole contains cuboid base (10), cylinder boss (11), through-hole (12), screw hole (13), through-hole (12) suit in the probe afterbody, passes boss (11) both sides screw hole (13) by countersunk screw (14) and fixes, and countersunk screw (14) are whole to be embedded in screw hole (13).

9. Further, cuboid base (10) contains four rectangle sides and two square bottom surfaces, two adjacent sides mutually perpendicular in four sides, four sides all can regard as the locating surface, a bottom surface is connected with cylinder boss (11) in base (10), the plumb line and boss (11) axis coincidence of bottom surface, boss (11) axis and through-hole (12) central line coincidence, the through-hole diameter is D +0.05 millimeter, boss (11) external diameter is M, the value range is D +2 millimeters be less than or equal to M and is less than or equal to D +5 millimeters, base (10) bottom surface length of side is M to M +3 millimeters, base (10) thickness is H, the value range is 2 millimeters be less than or equal to H and is less than or equal to 5 millimeters.

The invention has the beneficial effects that:

compared with other double-hole dynamic pressure probes, the invention provides a small-disturbance high-resolution dynamic probe for measuring secondary flow at a static and rotating middle end region, which has the following beneficial effects:

the beneficial effects are that: the probe head adopts a double-twisted-wire rotating body structure, the vertical distance between the centers of the two pressure sensing holes and the lowest point of the surface of the double-twisted-wire rotating body is smaller, and the dynamic parameters of the secondary flow field in an end region closer to the wall surface can be measured.

The beneficial effects are that: the double-twisted-line rotating body is in smooth curved surface transition with the cylinder at the head of the probe, when airflow flows through the surface of the double-twisted-line rotating body, the special structure of the double-twisted-line rotating body can inhibit the airflow separation of the airflow on the surface of the double-twisted-line rotating body and weaken the interference of the streaming around the head of the supporting rod on the flow field of a measured area, and on the other hand, when the flow field parameters are measured close to the end wall, the double-twisted-line rotating body can inhibit the scale of the horseshoe vortex at the front end of the head of the probe and reduce the measurement error.

The beneficial effects are three: the rotary body is flat, the distance between the circle center of the inclined hole and the circle center of the main hole is closer by the structure, the space resolution of the probe is improved, and the dynamic pressure sensor communicated with the inclined hole can be installed closer to the inclined hole, so that the volume of the accommodating cavity between the inclined hole and the sensor is reduced to a great extent, the effect of the accommodating cavity is reduced, and the frequency response of the probe is improved.

The beneficial effects are four: the probe has relatively small head size, can be inserted into the dynamic change of secondary flow field parameters of a turbine rotor-stator measurement end region, and has small interference on a measured flow field.

The beneficial effects are five: the positioning block adopted by the invention has small size, the influence on the probe is small in the measuring process, and because four side surfaces of the positioning block can be used as positioning surfaces and can be replaced mutually, the positioning process is simple and convenient, and the positioning method is more suitable for practical engineering application.

Drawings

Fig. 1 is a schematic structural view of the present invention.

FIG. 2 is a lemniscate revolution generation process.

Fig. 3 is a right side view of fig. 1.

Fig. 4 is a partially enlarged view of fig. 3.

Fig. 5 is a top view of fig. 3.

FIG. 6 is a test layout of probes.

Wherein: 1-probe head, 2-probe support rod, 3-cylinder, 4-lemniscate revolution body, 5-inclined hole, 6-positive hole, 7-dynamic pressure sensor, 8-cable of dynamic pressure sensor, 9-positioning block, 10-cuboid base, 11-cylinder boss, 12-through hole, 13-threaded hole, 14-countersunk screw, 15-casing, 16-rotor, 17-stator, 18-hub.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments.

As shown in fig. 1, the present embodiment introduces a small-disturbance high-resolution dynamic probe for measuring secondary flow in a rotating-static middle region, which is composed of a probe head (1), a supporting rod (2), a dynamic pressure sensor (7), and a positioning block (9), and is characterized in that: the probe head (1) is a cylinder (3) and a double-twisted-wire spinning body (4) which share the same bottom surface, the joint of the cylinder (3) and the double-twisted-wire spinning body (4) is in smooth curved surface transition, and 2 dynamic pressure sensors (7) are packaged in the probe head (1); a pressure sensing hole which is an inclined hole (5) is formed in the side face of the double-twisted-wire rotating body (4), and the inclined hole (5) is communicated with a dynamic pressure sensor (7) packaged in the probe head (1); another pressure sensing hole is formed in the side face of the cylinder (3) on the same side of the double-twisted-line rotating body (4) where the inclined hole (5) is located, the other pressure sensing hole is a positive hole (6), and the positive hole (6) is communicated with another dynamic pressure sensor (7) which is packaged; the central line of the inclined hole (5) and the central line of the positive hole (6) are on the same plane with the axis of the cylinder (3) of the probe head (1); the axis of the cylinder (3) of the probe head (1) is coincided with the axis of the probe supporting rod (2).

The diameter of the probe head (1) and the cylinder (3) is 3.5 mm, and the length is 15 mm.

The rotating body (4) is formed by rotating an AB curve section on a lemniscate around a shaft L, a point A is an intersection point of the lemniscate, a tangent line of a point B is perpendicular to a tangent line of the point A, and a rotating shaft L passes through the point A and is perpendicular to the tangent line of the point A.

The diameter of the inclined hole (5) is 0.3 mm, and the included angle between the central line of the inclined hole (5) and the axial line of the cylinder (3) of the probe head (1) is 73 degrees.

The vertical distance between the circle center of the inclined hole (5) and the lowest point of the surface of the twisted pair body (4) is 0.2 mm.

The diameter of the positive hole (6) is 0.3 mm, and the vertical distance between the circle center of the positive hole (6) and the lowest point of the surface of the rotating body (4) is 1 mm.

The probe supporting rod (2) is a cylinder, the diameter of the probe supporting rod is 6 mm, a circular pipeline is arranged in the probe supporting rod, a cable (8) of a dynamic pressure sensor packaged in the probe head (1) is led out of the probe tail part through the pipeline in the probe supporting rod (2), and a positioning block (9) is sleeved on the probe tail part.

Locating piece (9) structure as an organic whole contains cuboid base (10), cylinder boss (11), through-hole (12), screw hole (13), through-hole (12) suit in the probe afterbody, passes boss (10) both sides screw hole (13) by countersunk screw (14) and fixes, and countersunk screw (14) are whole to be embedded in screw hole (13).

Cuboid base (10) contains four rectangle sides and two square bottom surfaces, two adjacent sides mutually perpendicular in four sides, the locating surface can all be regarded as to four sides, a bottom surface is connected with cylinder boss (11) in base (10), the perpendicular bisector and boss (11) axis coincidence of bottom surface, boss (11) axis and through-hole (12) central line coincidence, the through-hole diameter is 6.05 millimeters, the boss external diameter is 9 millimeters, base (10) bottom surface length of side is 11 millimeters, base (10) thickness is 3 millimeters.

Calibrating the probe in a subsonic calibration wind tunnel, selecting one side surface of a base (10) of a positioning block (9) as a positioning surface, determining the relative position of the positioning surface of the positioning block (9) and a front hole (6) through a level gauge, fixing the positioning block (9) through a countersunk head screw (14), and obtaining the pneumatic calibration coefficient of the probe in different incoming flow directions and different Mach numbers;

in actual measurement, a probe is installed and fixed on a displacement mechanism, the specific process is that a level gauge is utilized to adjust the level of a positioning surface of the displacement mechanism, the probe is installed on the displacement mechanism, the level gauge is placed on the positioning surface of a probe positioning block (9), the probe is rotated along the axis of a probe supporting rod (2), the level of the positioning surface is adjusted through the level gauge, the relative position of the central line of a front hole (6) and the positioning surface of the displacement mechanism is determined, and the probe is fixed on the displacement mechanism; the displacement mechanism for installing the probe is installed on a turbine casing (15) to be measured through a positioning device, a certain radial position of a flow field in an insertion end region of the probe is adjusted through the displacement mechanism, as shown in fig. 6, according to a known average incoming flow direction, the probe is adjusted through the displacement mechanism, a positive hole (6) is aligned to the average incoming flow direction, the position is taken as a reference, the displacement mechanism is utilized to drive the probe to rotate around the axis of a probe supporting rod (2) by 1 angle in the anticlockwise direction and the clockwise direction respectively, the rotation angle is 40 degrees, 3 angular positions are measured in total, and under each angular position, the airflow pitch angle, the airflow deflection angle, the total pressure, the static pressure and the Mach number of the measured flow field are calculated by combining the aerodynamic calibration coefficients of the probe obtained by a subsonic calibration wind tunnel under different incoming flow directions and different Mach numbers.

The invention has the positioning function, the adopted positioning block (9) has small size, the influence on the probe is small in the measuring process, the four side surfaces can be used as positioning surfaces and can be replaced mutually, the positioning process is simple and convenient, and the invention is more suitable for practical engineering application. The vertical distance between the circle center of the pressure sensing hole inclined hole (5), the circle center of the positive hole (6) and the lowest point of the surface of the twisted-pair line rotating body (4) is small, and the dynamic parameters of a secondary flow field in an end region, which is closer to the wall surface, between a rotor (16) and a stator (17) of a turbine can be measured; the twisted pair rotary body (4) of the probe head (1) can inhibit the separation of air flow when the air flow flows through the surface of the probe head, reduce the interference of the streaming of the support rod head to a measured flow field, and when the flow field parameters of the near-wall end region are measured, the twisted pair rotary body (4) can also inhibit the scale of the horseshoe vortex at the front end of the probe head (1), so the structure can reduce the measurement error of the secondary flow field of the end region; the rotation body (4) is flat, so that the distance between the circle center of the inclined hole (5) and the circle center of the main hole (6) can be closer to one another, the spatial resolution of the probe is improved, and the dynamic pressure sensor (7) communicated with the inclined hole (5) can be closer to the inclined hole (5) to be installed, so that the volume of the accommodating cavity between the inclined hole (5) and the sensor can be greatly reduced, the effect of the accommodating cavity is reduced, and the frequency response of the probe is improved. The probe head (1) has relatively small size and small interference to a measured flow field, and can be inserted into a secondary flow pitch angle, a flow deflection angle, total pressure, static pressure and dynamic change of Mach number of a measurement end region between a rotor (16) and a stator (17) of a turbine.