WO2021174681A1

WO2021174681A1 - Composite five-hole pressure-temperature probe

Info

Publication number: WO2021174681A1
Application number: PCT/CN2020/091482
Authority: WO
Inventors: 钟兢军; 阚晓旭; 杨凌; 吴宛洋
Original assignee: 上海海事大学
Priority date: 2020-03-06
Filing date: 2020-05-21
Publication date: 2021-09-10
Also published as: CN111220348A

Abstract

A composite five-hole pressure-temperature probe, comprising one total temperature thermocouple (11), five pressure-measuring tubes (6-10), four static pressure-measuring tubes (13-16) and four static temperature thermocouples (17-20) that are disposed inside a probe rod body (4), wherein the front end of the probe rod body (4) is a static parameter section (3), the rear end of the probe rod body (4) is a lead-out section (5), and a transition section (2) connects a pressure-measuring head (1) and the static parameter section (3); detection ends of the total temperature thermocouple (11) and the pressure-measuring tubes (6-10) are disposed the end part of the pressure-measuring head (1); and detection ends of the static pressure-measuring tubes (13-16) and the static temperature thermocouples (17-20) are disposed on the side wall of the static parameter section (3), and all of the pressure-measuring tubes (6-10,13-16) and thermocouples (11,17-20) extend out from the lead-out section. The composite five-hole pressure-temperature probe may measure the total temperature, static temperature, total pressure, static pressure, Mach number, three-dimensional flow velocity, airflow deflection angle and pitch angle, and other pneumatic parameters under the conditions of transonic flow and supersonic flow at the same time and in the same place, which effectively reduces the interference of the probe on a flow field and achieves accurate measurement.

Description

A composite five-hole pressure-temperature probe

Technical field

The invention relates to the field of pressure, temperature and speed testing, in particular to a composite five-hole pressure-temperature probe.

Background technique

Pneumatic probe is the most important and convenient measuring tool in the wind tunnel experiment of impeller machinery. In the prior art, the commonly used five-hole pneumatic pressure probe can only measure the total pressure, static pressure, Mach number, deflection angle and pitch angle of the air flow at the measuring point. For the measurement of the three-dimensional velocity value of the airflow, it is necessary to cooperate with an additional temperature sensor to indirectly calculate the three-dimensional velocity value through the measured total temperature.

In the turbomachine wind tunnel experiment, temperature probes are mostly placed in the stable section of the wind tunnel to measure the airflow temperature under low-speed and high-subsonic flow conditions, and the temperature of the airflow between the stable section of the wind tunnel and the measurement point is ignored. Poor, this kind of processing that ignores small errors is acceptable under low-speed and high-subsonic flow conditions. However, under the conditions of cross and supersonic flow, due to the shock wave structure in the pressure measuring head of the pneumatic probe, the local entropy will increase, and the temperature of the air flow will have a step change. In this case, it is necessary to measure the same measuring point. The pressure and temperature values at the location. However, in the existing technology, one way is to use a separate pneumatic pressure probe and a separate temperature probe to measure the pneumatic parameters at the measuring point in turn. This method can measure the same space, but not the same time. Parameters; one way is to use a combination of pressure probe and temperature probe to measure pneumatic parameters at one time, but most of the combined probes shown in the published literature are two independent probes combined by binding, welding, etc. At the same time, the two probes are not completely at the same spatial position, and it can be considered that the aerodynamic parameters can be measured at the same time but not in the same space. In addition, the geometric dimensions of such probes are larger than those of ordinary pneumatic probes, which will cause greater interference to the flow field.

Therefore, most of the current pneumatic probes cannot obtain aerodynamic parameters such as total temperature, static temperature, total pressure, static pressure, Mach number, three-dimensional flow velocity, deflection angle and pitch angle of the same space at the same time.

Disclosure of invention

The invention provides a composite five-hole pressure-temperature probe that can simultaneously and simultaneously measure the total temperature, static temperature, total pressure, static pressure, Mach number, three-dimensional flow rate, and airflow under the conditions of transonic and supersonic incoming flow. The aerodynamic parameters such as yaw angle and pitch angle can effectively reduce the probe's interference to the flow field and realize accurate measurement.

In order to achieve the above objective, the present invention provides a composite pneumatic probe, comprising: a total temperature thermocouple, five pressure measuring tubes, four static pressure measuring tubes and four static pressure measuring tubes arranged inside the probe shaft. For thermocouples, the front end of the probe shaft is the static parameter section, the rear end of the probe shaft is the lead-out section, and the transition section connects the pressure measuring head and the static parameter section;

The detecting end of the total temperature thermocouple and the pressure measuring tube is arranged at the end of the pressure measuring head, and the detecting end of the static pressure measuring tube and the static temperature thermocouple is arranged on the side of the static parameter section. The wall, all pressure measuring tubes and thermocouples protrude from the lead-out section.

The end of the pressure measuring head is a cone, and the half angle of the cone is 10°-35°.

The one total temperature thermocouple and one pressure measuring tube are arranged at the center of the end of the pressure measuring head, and the remaining four pressure measuring tubes are orthogonal around the center of the pressure measuring head Symmetrical arrangement.

The detection end of the total temperature thermocouple is equipped with a stagnation cover.

The transition section is a regular rotating body with a variable diameter, and the diameter of one end of the transition section connected to the pressure measuring head is smaller than the diameter of the end connected to the static parameter section.

The four static pressure measuring tubes are arranged orthogonally and symmetrically on the side wall of the static parameter section; the detection ends of the four static temperature thermocouples are arranged orthogonally and symmetrically on the side wall of the static parameter section. The pressure measuring tube and the static temperature thermocouple are alternately arranged with each other.

The distance between the detection end of the static pressure measuring tube and the static temperature thermocouple and the end of the pressure measuring head is greater than or equal to 10 times the outer diameter of the conical head plane of the pressure measuring head. The distance between the detection end of the static pressure measuring tube and the static temperature thermocouple and the horizontal to vertical turning section of the probe shaft is greater than or equal to 5 times the outer diameter of the conical head plane of the pressure measuring head, so The diameter of the static parameter section is less than or equal to twice the maximum diameter of the pressure measuring head.

The lead-out section has a petal-like structure, the five pressure measuring tubes are arranged linearly on the lead-out section, and one of the pressure measuring tubes is arranged in the middle; the one total temperature thermocouple and four The static temperature thermocouples are arranged linearly on the lead-out section, and one of the total temperature thermocouples is arranged in the middle; the four static pressure measuring tubes are arranged symmetrically in the linearly arranged pressure measuring tubes and static temperature thermoelectrics Even on both sides.

The present invention has the following advantages:

1. The total temperature thermocouple is embedded in the probe pressure measuring head tube sleeve, instead of being bundled outside the probe shaft, so that the size of the pressure measuring head is greatly reduced and can be maintained at the same size as the traditional pressure probe. , Effectively reducing the interference of the composite probe to the flow field.

2. The transition section is used to connect the five-hole probe of the pressure measuring head and the static pressure probe and the static temperature probe of the static parameter section, so that the supersonic airflow generates a series of weak oblique shock waves on the transition section profile, thereby reducing The supersonic airflow is in an isentropic compression flow state, which provides a guarantee for accurately measuring the static pressure of the airflow that is not affected by the shock wave structure.

3. Adopt the transition section variable diameter structure to make the geometric size of the probe pressure measuring head as small as possible, and the geometric size of the probe shaft body as large as possible, which can weaken the interference degree of the probe pressure measuring head affecting the flow field, and It can improve the impact force of the probe shaft to withstand the supersonic flow.

4. The columnar stainless steel tube with simple structure and convenient purchase is adopted, which is easy to process, install and operate, ensuring that the probe has low manufacturing and maintenance costs.

Brief description of the drawings

Fig. 1 is a main structure diagram of a composite five-hole pressure-temperature probe provided by the present invention.

Figure 2 is a flow cross-sectional view of the pressure measuring tube and temperature thermocouple structure of a composite five-hole pressure-temperature probe provided by the present invention.

Figures 3A to 3D show the structural layout of the pressure measuring head of a composite five-hole pressure-temperature probe provided by the present invention.

4 is a normal cross-sectional view of the structure of a static pressure measuring tube and a static temperature thermocouple of a composite five-hole pressure-temperature probe provided by the present invention.

Fig. 5 is a structural layout of the lead-out section of a composite five-hole pressure-temperature probe provided by the present invention.

Fig. 6 is a top view of the lead-out section of a composite five-hole pressure-temperature probe provided by the present invention.

The best way to implement the invention

Hereinafter, a preferred embodiment of the present invention will be described in detail based on FIGS. 1 to 6.

As shown in Figure 1, the present invention provides a composite five-hole pressure-temperature probe, comprising: a total temperature thermocouple, five pressure measuring tubes, and four static pressure measuring tubes arranged inside the probe shaft 4 Pressure tube and four static temperature thermocouples, the front end of the probe shaft 4 is the static parameter section 3, the rear end of the probe shaft 4 is the lead-out section 5, and the transition section 2 connects the pressure measuring head 1 and the static parameter section 3. The probe shaft 4 functions to wrap all the pressure measuring tubes and temperature thermocouples, and enhance the structural strength of the entire probe. The detection end of the total temperature thermocouple and the pressure measuring tube is set at the end of the pressure measuring head 1. The total temperature thermocouple and the pressure measuring tube pass through the pressure measuring head 1, the transition section 2, the static The parameter section 3 and the probe shaft 4 finally extend from the lead section 5. The detection ends of the static pressure measuring tube and the static temperature thermocouple are arranged on the side wall of the static parameter section 3. The static pressure measuring tube and the static temperature thermocouple pass through the static parameter section 3 and the probe shaft 4 in sequence, Finally, it extends from the lead-out section 5. All pressure measuring tubes and thermocouples extending from the lead-out section 5 can be connected to a digital sensor array pressure test module (DSA) and a distributed optical fiber temperature sensing system (DTS) through a pneumatic connector.

As shown in Figure 2, in an embodiment of the present invention, the end of the pressure measuring head 1 is a cone, the cone half-angle is 10°～35°, and the diameter is based on the pressure measuring tube and the total temperature. The geometric dimensions of the galvanic couple are determined.

As shown in Figures 2 and 3A to 3D, in one embodiment of the present invention, five pressure measuring tubes are included, of which, an intermediate pressure measuring tube 7 and the total temperature thermocouple 11 are located on the pressure measuring head The center position of section 1. According to the structure of the pressure measuring head, there are four schemes for the layout of the intermediate pressure pressure measuring tube 7 and the total temperature thermocouple 11: as shown in Figure 3A, the first scheme is that the total temperature thermocouple 11 is in the middle pressure measuring tube 7 Above; As shown in Figure 3B, the second option is that the total temperature thermocouple 11 is on the left side of the intermediate pressure piezometric tube 7; as shown in Figure 3C, the third option is that the total temperature thermocouple 11 is below the intermediate pressure piezometric tube 7; As shown in Fig. 3D, the fourth solution is that the total temperature thermocouple 11 is on the right side of the intermediate pressure pressure measuring tube 7. The remaining four

pressure measuring tubes

6, 8, 9 and 10 are arranged in orthogonal symmetry around the center of the pressure measuring head 1. Specifically, along the airflow direction, the pressure piezometer tube 6 is in the lower position, the pressure piezometer tube 8 is in the upper position, the pressure piezometer tube 9 is in the left position, and the pressure piezometer tube 10 is in the right position. The diameter of each pressure measuring tube and the diameter of the total temperature thermocouple 11 can be adjusted according to the specific structure size.

In an embodiment of the present invention, the detection end of the total temperature thermocouple 11 is not directly arranged at the tip of the pressure measuring head 1, but a stagnation cover is added, the size of which can be adjusted according to the specific structure. Specifically, this stagnation hood reduces the speed of the supersonic airflow flowing into the pressure measuring head to a certain extent, thereby reducing the velocity error to the allowable range of airflow Ma<0.2, thereby ensuring the total temperature measured by the thermocouple It is the precise total air temperature.

As shown in FIG. 2, in an embodiment of the present invention, the transition section 2 is a regular rotating body with variable diameter, one end of which is connected to the pressure measuring head 1, and the other end is connected to the static parameter section 3. The diameter of the end of the transition section 2 connected to the pressure measuring head 1 is smaller than the diameter of the end connected to the static parameter section 3. The function of the transition section 2 profile is: the supersonic airflow passing through the transition section 2 profile will produce a series of weak oblique shock waves. This oblique shock wave system can decelerate the supersonic air flow until it drops to subsonic speed. Because each oblique shock wave is very weak, the supersonic flow through the oblique shock wave system is close to isentropic compression. According to this, by measuring the static pressure and static temperature of the subsonic airflow on the static parameter section after the transition section, the static pressure and static temperature of the supersonic flow can be calculated. At the same time, the reduced-diameter structure design of the transition section 2, on the one hand, reduces the geometric size of the pressure measuring head 1 as much as possible, thereby reducing the interference of the pneumatic probe on the wind tunnel experiment of the impeller machinery; on the other hand, it increases The geometric size of the probe shaft 4 improves the stability of the pneumatic probe in the supersonic airflow.

As shown in Figures 2 and 4, in an embodiment of the present invention, four static pressure measuring tubes 13-16 and four static temperature thermocouples 17-20 are included, and static pressure measuring tubes 13-16 and The detection ends of the static temperature thermocouples 17-20 are arranged orthogonally and symmetrically on the side wall of the static parameter section 3. According to the principle of experimental aerodynamics, the measurement of static parameters is a component perpendicular to the direction of airflow. Therefore, in order to ensure the accuracy of the collection in this vertical direction, it is necessary to set the static pressure test tube and the static temperature thermocouple in the static parameter section 3. The outer wall. As shown in Figure 4, the structural form of the static pressure test tube 13-16 presents an orthogonal symmetrical arrangement. Specifically, along the airflow direction, the static pressure test tube 13 is in the upper position, and the static pressure test tube 14 is in the right position. The static pressure piezometer 15 is in the lower position, and the static pressure piezometer 16 is in the left position. The structure of static temperature thermocouples 17-20 presents an orthogonal symmetrical arrangement. Specifically, along the direction of the airflow, static temperature thermocouple 17 is in the upper right position, static temperature thermocouple 18 is in the lower right position, and static temperature thermocouple is in the lower right position. 19 is in the lower left position, and the static temperature thermocouple 20 is in the upper left position. According to the literature, the measurement of static parameters is affected by the interference of the probe head and the vertical part of the probe shaft. For the accuracy of the measurement, the measurement position of the static parameters needs to be outside the two interference regions. As shown in Figure 2, the distance between the probe end of the static pressure measuring tube and the static temperature thermocouple from the tip of the pressure measuring head 1 can be equal to 10 times the conical head plane of the pressure measuring head according to the flow field measurement requirements. The outer diameter (ie 10d) or longer. At the same time, the distance between the detection end of the static pressure test tube and the static temperature thermocouple from the horizontal to vertical turning section of the probe shaft 4 can be equal to 5d or longer according to the flow field measurement requirements. The diameter of the static parameter section 3 does not exceed twice the diameter of the end of the pressure measuring head 1 (the end refers to the end connecting the pressure measuring head 1 and the transition section 2), so as to avoid large deviations causing the collected airflow to be different from the same streamline.

As shown in Figures 5 and 6, in an embodiment of the present invention, the lead-out section 5 presents a petal-like structure, and the lead-out section 5 leads to various pressure measuring tubes and thermocouples, and various pressure measuring tubes and thermoelectrics. Even connect the pneumatic connector. Specifically, the intermediate pressure measuring tube 7 is arranged in the middle of the rear row, and the remaining

pressure measuring tubes

6, 8, 9 and 10 and the intermediate pressure measuring tube 7 can be arranged linearly. The total temperature thermocouple 11 is arranged in the middle of the front row, and the remaining static temperature thermocouples 17-20 are arranged linearly with the total temperature thermocouple 11. The static pressure measuring tubes 13-16 are symmetrically arranged on both sides of the linearly arranged pressure measuring tubes and static temperature thermocouples.

The present invention is calibrated by the supersonic wind tunnel. In the actual measurement process, the pressure measurement system measures the pressure felt by the pressure measuring tubes 6-10 of the pressure measuring head 1, and converts it into a total pressure calibration coefficient C _pt and a static pressure calibration coefficient C _ps and directional characteristic calibration coefficients K _α , K _β , according to the calibration algorithm, the total pressure, static pressure, Mach number, pitch angle, and deflection angle can be obtained. The total temperature and the static temperature can be obtained through the electrical signals output by the total temperature thermocouple 11 and the static temperature thermocouple 17-20 and the calibration relationship. The speed can be obtained by converting the total temperature, static temperature, and Mach number that have been obtained.

In summary, the present invention can simultaneously measure the total temperature, static temperature, total pressure, static pressure, Mach number, three-dimensional flow velocity, deflection angle and pitch angle of the airflow and other aerodynamic parameters under the conditions of transonic and supersonic flow at the same place. It is used for wind tunnel experiments in impeller machinery and other related fields, and can achieve accurate measurements.

Compared with the prior art, the composite five-hole pressure-temperature probe designed by the present invention can achieve the following technical effects:

2. The transition section is used to connect the five-hole probe of the pressure measuring head and the static pressure probe and the static temperature probe of the static parameter section, so that the supersonic airflow produces a series of weak oblique shock waves on the transition section profile, thereby reducing The supersonic airflow is in an isentropic compression flow state, which provides a guarantee for accurately measuring the static pressure of the airflow that is not affected by the shock wave structure.

3. Adopt the transition section variable diameter structure to make the geometric size of the probe pressure measuring head as small as possible, and the geometric size of the probe shaft meets sufficient strength, which can weaken the interference degree of the probe pressure measuring head affecting the flow field. , And can improve the probe shaft to withstand the impact of supersonic flow.

4. The pressure measuring head 1, the transition section 2, the static parameter section 3, the probe rod body 4, and the lead-out section 5 are all made of cylindrical stainless steel pipes with simple structure and convenient purchase. It is easy to process, install and operate to ensure that the probe has Lower manufacturing and maintenance costs.

The invention is a composite five-hole pressure-temperature probe with a total temperature and static temperature thermocouple embedded in a traditional pressure probe, which realizes the total temperature and static temperature of the convection field under the conditions of transonic and supersonic flow. Measurement of aerodynamic parameters such as temperature, total pressure, static pressure, Mach number, three-dimensional flow velocity, deflection angle and pitch angle of airflow at the same time, can effectively control the geometric size of the probe, so as to prevent the convection field from being too large. The greater interference.

It should be noted that the "up", "down", "left", "right", and "front" mentioned in the above-mentioned embodiments of the present invention are based on the directions shown in each figure, and these are used to The terms restricting the direction are only for convenience of description, and do not represent a limitation to the specific technical solutions of the present invention.

Although the content of the present invention has been described in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as limiting the present invention. After those skilled in the art have read the above content, various modifications and substitutions to the present invention will be obvious. Therefore, the protection scope of the present invention should be defined by the appended claims.

Claims

A composite five-hole pressure-temperature probe, which is characterized by comprising: a total temperature thermocouple, five pressure measuring tubes, four static pressure measuring tubes and four static pressure measuring tubes arranged inside the probe shaft. For thermocouples, the front end of the probe shaft is the static parameter section, the rear end of the probe shaft is the lead-out section, and the transition section connects the pressure measuring head and the static parameter section;

The detecting end of the total temperature thermocouple and the pressure measuring tube is arranged at the end of the pressure measuring head, and the detecting end of the static pressure measuring tube and the static temperature thermocouple is arranged on the side of the static parameter section. The wall, all pressure measuring tubes and thermocouples protrude from the lead-out section.
The composite five-hole pressure-temperature probe according to claim 1, wherein the end of the pressure measuring head is a cone, and the cone half-angle is 10°-35°.
The composite five-hole pressure-temperature probe according to claim 1, wherein said one total temperature thermocouple and one pressure measuring tube are arranged at the end of said pressure measuring head At the center position, the remaining four pressure measuring tubes are arranged orthogonally and symmetrically around the center of the pressure measuring head.
The composite five-hole pressure-temperature probe according to claim 3, wherein the detection end of the total temperature thermocouple is equipped with a stagnation cover.
The composite five-hole pressure-temperature probe according to claim 1, wherein the transition section is a regular rotating body with a variable diameter, and the diameter of one end of the transition section connected to the pressure measuring head is smaller than The diameter of one end connecting the static parameter segment.
The composite five-hole pressure-temperature probe according to claim 1, wherein the four static pressure measuring tubes are arranged orthogonally and symmetrically on the side wall of the static parameter section; the four static temperature The detection end of the thermocouple is arranged orthogonally and symmetrically on the side wall of the static parameter section, and the static pressure measuring tube and the static temperature thermocouple are alternately arranged with each other.
The composite five-hole pressure-temperature probe according to claim 1, wherein the distance between the detection end of the static pressure measuring tube and the static temperature thermocouple and the end of the pressure measuring head The outer diameter of the conical head plane of the pressure measuring head that is greater than or equal to 10 times.
The composite five-hole pressure-temperature probe according to claim 1, wherein the detection end of the static pressure measuring tube and the static temperature thermocouple is between the horizontal to vertical turning section of the probe shaft. The distance between them is greater than or equal to 5 times the outer diameter of the conical head plane of the pressure measuring head.
The composite five-hole pressure-temperature probe according to claim 1, wherein the diameter of the static parameter section is less than or equal to twice the maximum diameter of the pressure measuring head.
The composite five-hole pressure-temperature probe according to claim 1, wherein the lead-out section has a petal-like structure, and the five pressure measuring tubes are linearly arranged on the lead-out section, one of which is A pressure measuring tube is set in the middle; the one total temperature thermocouple and four static temperature thermocouples are linearly arranged on the lead-out section, and one of the total temperature thermocouples is set in the middle; the four The static pressure measuring tube is symmetrically arranged on both sides of the linearly arranged pressure measuring tube and the static temperature thermocouple.