A prism-shaped five-hole probe for measuring all dynamic parameters of subsonic three-dimensional flow field

Abstract

The present invention belongs to the technical field of impeller test and measurement, and discloses a prism five-hole probe for measuring the dynamic full parameters of a subsonic three-dimensional flow field, including a probe support rod, a transition section, a probe head, a pressure sensor cable, a temperature sensor cable, a heat-insulating seal and a temperature sensor, wherein the probe support rod and the probe head are both cylindrical and connected through a transition section, and the pressure measuring lower hole, the pressure measuring left hole, the pressure measuring right hole, the pressure measuring middle hole and the temperature measuring hole are located on the prism protruding from the probe head, and the temperature measuring hole is grooved on the circumference, and the pressure sensor and the temperature sensor cable are led out of the probe tail through the channel in the probe support rod. The present invention can realize the dynamic measurement of the total pressure, static pressure, deflection angle, pitch angle, Mach number, density and three-dimensional velocity as well as the total temperature and static temperature at the same point in the flow field under the premise of reducing the influence of the flow around the probe head, and has a wide total temperature insensitive angle measurement range, and is suitable for measuring the full-parameter dynamic measurement of the three-dimensional flow field between stages of an aeroengine.

Description

Technical Field

[0001] The present invention relates to the technical field of turbine testing, and in particular to a prism-shaped five-hole probe for measuring all dynamic parameters of a subsonic three-dimensional flow field, which is used for the dynamic measurement of all flow field parameters of an aircraft engine inlet, a compressor interstage, and a compressor inlet and outlet. Background Art

[0002] At present, in the field of turbomachinery testing, especially in the field of aero-engine flow field testing, pressure probes and temperature probes are widely used for pressure and temperature measurement. Although the pressure probe can measure the total pressure, static pressure, Mach number, and flow direction, it cannot measure temperature, so the flow velocity of the flow field cannot be calculated from the data measured by the pressure probe. At present, the temperature of the incoming flow is usually measured by a separate total temperature probe to measure the total temperature of the incoming flow, but it cannot achieve the synchronous measurement of total pressure, static pressure, pitch angle, deflection angle, Mach number, density, three-dimensional velocity, and total temperature and static temperature.

[0003] Although there are a few temperature-pressure combination probes, the temperature measuring holes and pressure measuring holes are directly opened on the "┃"-shaped structure of the probe head. The "┃" cylindrical probe cannot realize three-dimensional measurement of flow field parameters by drilling holes on the cylindrical wall. The probes that can realize three-dimensional measurement have two structures, "I" type and "L" type. However, the "I" type probe cannot be installed in narrow spaces such as aircraft engine stages for testing. Although it can be installed in the inlet section of the aircraft engine, the probe head and support rod will have a great impact on the flow field; the "L" type is difficult to install in the narrow area between stages. In addition, although the bending section of the probe head of the "L" type probe has less impact on the probe head and the measured flow field than the "I" type during the measurement process, the impact on the flow field will still lead to inaccurate measurement results, which cannot be ignored.

[0004] In terms of total temperature measurement, the existing total temperature probe generally uses the method of chamfering the temperature measurement hole to expand the insensitive angle of temperature measurement, but the range of increasing the insensitive angle of temperature measurement is limited, and it is difficult to meet the measurement requirements of the complex flow field inside the aircraft engine. The existing dynamic measurement probe generally uses an exposed temperature sensor, which is directly washed by the fluid and is easily affected by oil droplets, dust, etc. in the airflow, and is easy to be damaged, thereby reducing the life of the temperature sensor.

[0005] For the existing dynamic pressure probes, the internal profile of the total pressure hole is generally a straight transition, which causes a certain total pressure loss and leads to inaccurate measurement results. In addition, the straight transition will cause flow separation, and the fluctuations generated by the flow separation will interfere with the total pressure measurement results. For the existing dynamic pressure probes, the total pressure hole and the static pressure hole are generally opened on curved surfaces such as cylindrical surfaces, and the front end of the pressure sensor is a plane. Therefore, the pressure sensor cannot be flush-mounted. There will inevitably be sharp edges after the pressure sensor is installed, which will cause flow separation, and the fluctuations caused by these flow separations will also interfere with the total pressure and static pressure measurement results, resulting in inaccurate measurement results.

[0006] To sum up, the existing probes applied to the three-dimensional flow field measurement in aeroengines have the following deficiencies: 1. The pressure probe cannot measure the total temperature, static temperature, and three-dimensional velocity. The total temperature probe can only measure the total temperature of the oncoming flow and cannot synchronously measure the total pressure, static pressure, pitch angle, yaw angle, Mach number, density, three-dimensional velocity, and total temperature and static temperature. 2. Among the existing temperature-pressure combined probes, the "┃" type cannot measure the three-dimensional parameters of the flow field, the "一" type cannot be applied to the narrow space test between stages of aeroengines, and the bent section at the head of the "L" type probe will have a certain impact on the probe head and the measured flow field, resulting in inaccurate measurement results and difficulty in installation in the narrow area between stages. 3. The existing total temperature probes generally use the method of chamfering the temperature measurement hole to expand the insensitive angle of temperature measurement, but the range of increasing the insensitive angle of temperature measurement is limited, and it is difficult to meet the measurement requirements of the complex flow field inside aeroengines. 4. The existing dynamic measurement probes generally use exposed temperature sensors, and the temperature sensors are directly flushed by the fluid, which is easily affected by oil droplets, dust, etc.夹杂 in the air flow and is easily damaged, thus reducing the service life of the temperature sensors. 5. The internal profile of the total pressure hole of the existing dynamic pressure probes causes total pressure loss and flow separation, resulting in inaccurate total pressure measurement results. The cooperation between the opening surfaces of the total pressure hole and the static pressure hole and the pressure sensor will also cause the generation of flow separation, and the fluctuations caused by it will reduce the measurement accuracy of the total pressure and static pressure. Summary of the Invention

[0007] The core purpose of the present invention is to solve the following problems existing in the field of current probe three-dimensional testing: the pressure probe cannot realize the measurement of total temperature, static temperature and three-dimensional speed; the total temperature probe can only measure the total temperature of the incoming flow, and cannot realize the synchronous measurement of total pressure, static pressure, pitch angle, deflection angle, Mach number, density, three-dimensional speed and total temperature and static temperature; the flow around the head of the existing temperature-pressure combination probe affects the measured flow field, resulting in inaccurate measurement results and difficulty in installation in the narrow area between stages; the existing total temperature probe generally adopts the method of chamfering the temperature measuring hole to expand the insensitive angle range of temperature measurement, which is limited; the dynamic total temperature measurement probe adopts an exposed temperature sensor, which causes the temperature sensor to be directly washed by the fluid and is easily affected by oil droplets, dust, etc. mixed in the airflow, resulting in damage; the internal surface of the total pressure hole of the dynamic pressure probe causes total pressure loss and flow separation, resulting in inaccurate total pressure measurement results, and the cooperation between the opening surface of the total pressure hole and the static pressure hole and the pressure sensor causes flow separation, which reduces the measurement accuracy of total pressure and static pressure.

[0008] In view of the above-mentioned deficiencies in the prior art, the present invention provides a prism-shaped five-hole probe for measuring all dynamic parameters of a subsonic three-dimensional flow field. The prism-shaped structure with a protruding head can reduce the influence of the flow around the probe head on the probe measurement result. The pressure measuring holes are opened on each side of the prism, so as to realize the measurement of the total pressure, static pressure, deflection angle, pitch angle, Mach number, density and three-dimensional speed of the inter-stage flow field of the aircraft engine. The temperature measuring holes are grooved around the holes to expand the insensitive angle range of the total temperature measurement. The temperature sensor is located in the cavity inside the probe head. Compared with the existing dynamic total temperature measurement probe with a directly exposed temperature sensor, the temperature sensor can be prevented from being directly flushed by the fluid and is not easily damaged by oil droplets, dust and the like mixed in the airflow. The interior of the total pressure hole adopts a smooth transition of a micro-loss convergent surface, which reduces the total pressure loss and flow separation and improves the accuracy of the total pressure measurement. The total pressure hole and the static pressure hole are opened on the surface of the prism. Since the opening surface is a plane, the pressure sensor can be flushed, the flow separation is reduced, and the pressure measurement is more accurate.

[0009] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0010] A prism-shaped five-hole probe for measuring all dynamic parameters of a subsonic three-dimensional flow field, characterized in that it comprises a probe support rod (1), a transition section (2), a probe head (3), a pressure sensor cable (12), a temperature sensor cable (13), a heat-insulating seal (14) and a temperature sensor (15), wherein the probe support rod (1) and the probe head (3) are both cylindrical, and the probe head (3) is connected to the probe support rod (1) through the transition section (2); a protruding prism structure is provided on the probe head (3), a pressure measuring lower hole (4), a pressure measuring right hole (5), a pressure measuring left hole (6), a pressure measuring middle hole (7) and a temperature measuring hole (8) are located on the prism of the probe head (3), the center lines of all the measuring holes are perpendicular to the prism surface where they are located, and a groove (9), a groove (10) and a groove (11) are provided on the circumference of the temperature measuring hole (8), and the pressure sensor cable (12) and the temperature sensor cable (13) are led out of the probe tail through a channel in the probe support rod (1).

[0011] Preferably, the temperature measuring hole (8) is located directly above the pressure measuring middle hole (7), the center lines of the temperature measuring right hole (5), the pressure measuring left hole (6) and the pressure measuring middle hole (7) are in the same plane, the pressure measuring lower hole (4) is located on the prism inclined surface below the pressure measuring middle hole (7), the line connecting the center of the pressure measuring lower hole (4) and the pressure measuring middle hole (7) and the line connecting the center of the pressure measuring middle hole (7) and the temperature measuring hole (8) are in the same plane, the distances between the pressure measuring right hole (5) and the pressure measuring left hole (6) and the left and right sides of the surface on which they are located are equal, and the distances between the pressure measuring lower hole (4) and the upper and lower sides of the surface on which they are located are equal.

[0012] Preferably, the diameters of the pressure measuring lower hole (4), the pressure measuring right hole (5), the pressure measuring left hole (6) and the pressure measuring middle hole (7) are the same, all of which are 0.2 to 2 mm, and the inlet wall of the pressure measuring middle hole (7) adopts a smooth transition of a micro-loss convergent surface; the diameter of the temperature measuring hole (8) is 0.3 to 5 mm, and the distance between the temperature measuring hole (8) and the pressure measuring middle hole (7) is 1.1 to 1.2 times the diameter of the pressure measuring middle hole (7). The slot width of the temperature measuring hole (8) is 1 / 4 of the diameter of the temperature measuring hole (8), the length of the slot on the side of the prism is 0.5 to 0.6 times the height of the prism, and the distance from the temperature sensor (15) to the temperature measuring hole is 0.4 to 0.5 times the diameter of the probe head (3).

[0013] Preferably, the diameter of the probe head (3) is 6 to 8 mm, the height of the protruding prism is 0.2 to 0.3 times the diameter of the probe head (3), the bottom surface of the prism is tangent to the cylindrical surface of the probe head, the length along the axial direction of the probe is 5 to 10 mm, the length of the other side of the bottom surface of the prism is 1 / 8 to 1 / 6 times the circumference of the probe head (3), and the angle between the side edge of the prism and the top surface of the prism is 120 to 150°.

[0014] Preferably, the temperature sensor (15) is located inside the cylindrical cavity of the probe head (3), and the diameter of the cylindrical cavity is 1 / 6 to 1 / 5 times the diameter of the probe head (3).

[0015] Preferably, the probe support rod (1) is a cylindrical structure that plays a supporting role. A channel is opened inside the probe support rod (1), and the pressure sensor cable (12) and the temperature sensor cable (13) are led out of the probe tail through the channel inside the probe support rod (1).

[0016] Preferably, the temperature sensor (15) can be a thermocouple, a thermal resistor or an optical fiber temperature sensor.

[0017] Preferably, after wind tunnel calibration, calibration and data processing, a prism-shaped five-hole probe for measuring all dynamic parameters of a subsonic three-dimensional flow field of the present invention can realize dynamic measurement of total pressure, static pressure, pitch angle, deflection angle, Mach number, density, three-dimensional velocity, total temperature and static temperature at the same point in the flow field while reducing the influence of the flow around the probe head, and has a wider total temperature measurement insensitive angle, which can achieve higher-precision total pressure measurement.

[0018] The advantages and positive effects of the invention are:

[0019] Beneficial effect 1: The prism-shaped five-hole probe for measuring the full dynamic parameters of subsonic three-dimensional flow field in the present invention, compared with the existing "I"-type probe with holes directly punched on the cylindrical side of the probe, can realize three-dimensional measurement of flow field parameters. Compared with the existing "I"-type probe structure with holes punched on the top frustum commonly used to realize three-dimensional measurement, since the pressure measuring holes and the temperature measuring holes are located on the side of the probe, it is convenient to be installed in narrow spaces such as aircraft engine stages for testing. Compared with the existing "L"-type probe structure that can realize three-dimensional flow field testing, since the prism-shaped structure protruding from the probe head is smaller in size than the bending section of the "L"-type probe, it is more convenient to be installed in the narrow area between stages, and compared with the "L"-type probe, the impact on the probe head and the flow field is also smaller, thereby improving the accuracy of the test results.

[0020] Beneficial effect 2: Compared with the prior art, the prism five-hole probe for measuring the dynamic full parameters of the subsonic three-dimensional flow field in the present invention has slots around the temperature measuring hole. For the flow field with complex incoming flow direction, when the mainstream air enters from the temperature measuring hole, the slotted part can realize convective heat exchange, which expands the insensitive angle of temperature measurement; the slotted part can realize air intake and exhaust adaptively. For example, when the mainstream is facing the slot at a certain moment in the complex flow field, this area can intake air, and the remaining slotted areas and the temperature measuring hole part can also realize exhaust. Therefore, the convective heat exchange is enhanced by slotting around the temperature measuring hole, so that it has a wide range of total temperature measurement insensitive angles, and improves the accuracy of temperature measurement.

[0021] Beneficial effect three: The temperature sensor is located in the cavity inside the probe head. Compared with the existing dynamic total temperature measurement probe with directly exposed temperature sensor, it can avoid the temperature sensor being directly washed by fluid and is not easily damaged by oil droplets, dust, etc. mixed in the airflow.

[0022] Beneficial effect four: Compared with the prior art, the prism five-hole probe for measuring all dynamic parameters of subsonic three-dimensional flow field in the present invention can realize the synchronous measurement of total pressure, static pressure, pitch angle, deflection angle, Mach number, three-dimensional speed, total temperature and static temperature in the subsonic flow field test of aircraft engines, that is, it realizes the three-dimensional dynamic measurement of all parameters of subsonic flow field.

[0023] Beneficial effect five: The interior of the total pressure hole in the present invention adopts a smooth transition of a micro-loss convergent surface, which can significantly reduce the total pressure loss and flow separation compared with the existing total pressure hole using a straight transition, thereby improving the accuracy of total pressure measurement. A total pressure hole and a static pressure hole are opened on the surface of the prism. Compared with the existing pressure probe, since all faces of the prism are flat, and the pressure sensor is generally a cylinder, its front end is flat during installation. When the opening surface is flat, the pressure sensor can be flush installed, which reduces flow separation and makes the measurement of total pressure and static pressure more accurate.

[0024] The present invention has the characteristics of realizing dynamic measurement of total pressure, static pressure, pitch angle, deflection angle, Mach number, density, three-dimensional velocity, total temperature and static temperature at the same point in the flow field while reducing the influence of flow around the probe head, having a wider total temperature measurement insensitive angle and being able to realize higher-precision total pressure measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a front view of the probe structure of Example 1 of the present invention.

[0026] Figure 2 1 is a top view of the probe structure of Example 1 of the present invention.

[0027] Figure 3 It is a cross-sectional view of a prism structure of a probe structure according to an embodiment of the present invention.

[0028] Figure 4 This is a diagram of the cable channel layout of a pressure sensor according to an embodiment of the present invention.

[0029] Figure 5 This is the definition of the profile of the inlet section of the pressure measuring hole in Example 1 of the present invention.

[0030] Figure 6 This is a probe installation diagram of Example 1 of the present invention.

[0031] Figure 7 It is a front view of the probe structure of the second embodiment of the present invention.

[0032] Figure 8 It is a top view of the probe structure of the second embodiment of the present invention.

[0033] Fig. 9 It is a cross-sectional view of the prism structure of the probe structure according to the second embodiment of the present invention.

[0034] Fig.10 This is a cable channel layout diagram of the pressure sensor in Example 2 of the present invention.

[0035] Fig.11 This is the definition of the profile of the inlet section of the pressure measuring hole in the second embodiment of the present invention.

[0036] Fig.12 This is a probe installation diagram of the second embodiment of the present invention.

[0037] The markings and corresponding parts and surface names in the accompanying drawings include: 1-probe support rod; 2-transition section; 3-probe head; 4-pressure measuring hole; 5-pressure measuring hole; 6-pressure measuring hole; 7-pressure measuring hole; 8-temperature measuring hole; 9-temperature hole slot; 10-temperature hole slot; 11-temperature hole slot; 12-pressure sensor cable; 13-temperature sensor cable; 14-insulation seal; 15-temperature sensor. DETAILED DESCRIPTION

[0038] The core purpose of the present invention is to provide a prism-shaped five-hole probe for measuring all dynamic parameters of subsonic three-dimensional flow fields, so as to solve many problems in the current field of aero-engine flow field testing, such as the great influence of flow around the probe head on the accuracy of the measurement results and the small insensitive angle of temperature measurement.

[0039] The present invention is described in detail below in conjunction with the accompanying drawings and embodiments, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0040] Embodiment 1:

[0041] In this embodiment, the probe of the present invention is used for full parameter testing of the compressor interstage flow field. Since the space between the compressor stages is narrow, the probe is selected to have a smaller structural size to facilitate installation.

[0042] like Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, this embodiment introduces a prism-shaped five-hole probe for measuring all dynamic parameters of a subsonic three-dimensional flow field, comprising a probe support rod (1), a transition section (2), a probe head (3), a pressure sensor cable (12), a temperature sensor cable (13), a heat-insulating seal (14) and a temperature sensor (15). The probe support rod (1) and the probe head (3) are both cylindrical, and the probe head (3) is connected to the probe support rod (1) through the transition section (2); the probe head (3) has a protruding prism structure, and the pressure measuring lower hole (4), the pressure measuring right hole (5), the pressure measuring left hole (6), the pressure measuring middle hole (7) and the temperature measuring hole (8) are located on the prism of the probe head (3), and the center lines of all the measuring holes are perpendicular to the prism surface where they are located. The temperature measuring hole (8) is provided with grooves (9), grooves (10) and grooves (11) on its circumference, and the pressure sensor cable (12) and the temperature sensor cable (13) are led out of the probe tail through the inner channel of the probe support rod (1).

[0043] In this embodiment, the temperature measuring hole (8) is located directly above the pressure measuring middle hole (7), the center lines of the temperature measuring right hole (5), the pressure measuring left hole (6) and the pressure measuring middle hole (7) are in the same plane, the pressure measuring lower hole (4) is located on the prism inclined surface below the pressure measuring middle hole (7), the line connecting the center of the pressure measuring lower hole (4) and the pressure measuring middle hole (7) and the line connecting the center of the pressure measuring middle hole (7) and the temperature measuring hole (8) are in the same plane, the distances between the pressure measuring right hole (5) and the pressure measuring left hole (6) and the left and right sides of the surface on which they are located are equal, and the distances between the pressure measuring lower hole (4) and the upper and lower sides of the surface on which they are located are equal.

[0044] In this embodiment, the diameters of the pressure measuring lower hole (4), the pressure measuring right hole (5), the pressure measuring left hole (6) and the pressure measuring middle hole (7) are the same, all 2 mm, and the inlet wall of the pressure measuring middle hole (7) adopts a smooth transition of a micro-loss convergent surface; the diameter of the temperature measuring hole (8) is 3 mm, and the distance between the temperature measuring hole (8) and the pressure measuring middle hole (7) is 1.1 times the diameter of the pressure measuring middle hole (7). The slot width of the temperature measuring hole (8) is 1 / 4 of the diameter of the temperature measuring hole (8), the length of the slot on the side of the prism is 0.5 times the height of the prism, and the distance from the temperature sensor (15) to the temperature measuring hole is 0.4 times the diameter of the probe head (3).

[0045] In this embodiment, the diameter of the probe head (3) is 6 mm, the height of the protruding prism is 0.2 times the diameter of the probe head (3), the bottom surface of the prism is tangent to the cylindrical surface of the probe head (3), the length along the axial direction of the probe is 10 mm, the length of the other side of the bottom surface of the prism is 1 / 6 times the circumference of the probe head (3), and the angle between the side edge of the prism and the top surface of the prism is 120°.

[0046] In this embodiment, the temperature sensor (15) is located inside the cylindrical cavity of the probe head (3), and the diameter of the cylindrical cavity is 1 / 6 times the diameter of the probe head (3).

[0047] In this embodiment, the probe support rod (1) is a cylindrical structure that plays a supporting role. A channel is opened inside the probe support rod (1), and the pressure sensor cable (12) and the temperature sensor cable (13) are led out of the probe tail through the channel inside the probe support rod (1).

[0048] In this embodiment, the temperature sensor (15) can be a thermocouple, a thermal resistor or an optical fiber temperature sensor.

[0049] Figure 5 is the profile definition diagram of the inlet section of the pressure measuring hole. The following formula is the profile curve equation of the micro-loss convergence surface used in the design of the inlet wall of the pressure measuring hole (7). The connection point x m Select 0.3.

[0050]

[0051] In the formula, R2 is the outlet radius, L is the length of the inlet section of the pressure measuring hole, R1 is the inlet radius, and x m The coordinates of the connecting point between the front and rear segments.

[0052] The present invention provides a prism five-hole probe for measuring the dynamic full parameters of the subsonic three-dimensional flow field. The probe uses the characteristics of the fluid flow around the probe, uses the pressure measuring hole on the windward side of the probe surface to measure the pressure distribution on the probe surface, uses the temperature sensor in the temperature measuring hole on the probe surface to measure the total temperature of the airflow, and then uses the calibration coefficient obtained by the standard wind tunnel calibration to calculate the full parameters of the three-dimensional flow field between the compressor stages. The specific method of use is as follows:

[0053] The probe of the present invention needs to be calibrated before use to obtain the aerodynamic calibration curve of the probe. The probe calibration is carried out in a calibration wind tunnel. Within the calibration range, the probe deflection angle and pitch angle are changed at different Mach numbers. After aerodynamic calibration, the curves of the change of each calibration coefficient with the deflection angle, pitch angle and Mach number can be obtained; the calibration coefficients include the deflection angle coefficient, pitch angle coefficient, total pressure coefficient, static pressure coefficient and temperature recovery coefficient, which are defined as follows:

[0054]

[0055]

[0056]

[0057]

[0058]

[0059] Among them, C py Deflection angle coefficient, C pp Deflection angle coefficient, C pt is the total pressure coefficient, C psis the static pressure coefficient, C T is the temperature recovery coefficient, P t , P s and T t 、T s are the total pressure, static pressure, total temperature and static temperature of the calibration wind tunnel, P1, P2, P3 and P4 are the pressure values ​​measured by the middle pressure hole, the left pressure hole, the right pressure hole and the lower pressure hole, respectively. p The temperature value measured by the temperature sensor.

[0060] like Figure 6 As shown, the flow field measured by the prism five-hole probe for measuring the dynamic full parameters of the subsonic three-dimensional flow field of the present invention is placed with the pressure measuring hole (7) facing the incoming flow direction, and the center line of the probe support rod (1) being perpendicular to the incoming flow direction. The pressure measuring hole (7) of the probe head (3) can measure the total pressure of the incoming flow, and the temperature measuring hole (8) can measure the total temperature of the incoming flow. Based on the pressures measured by the three pressure measuring holes (4), (5), and (6), combined with the known calibration coefficient curve, the deflection angle, pitch angle, total pressure, static pressure and Mach number are interpolated. The incoming flow velocity is solved according to the following formula:

[0061]

[0062]

[0063]

[0064] c 2 =γRT s

[0065] P S = ρRT S

[0066] Among them, P t and P s is the total pressure and static pressure of the flow field, γ is the adiabatic index of the flow field, T t and T s is the total temperature and static temperature of the flow field, Ma is the Mach number of the flow field, v is the flow field velocity, ρ is the density, c is the local sound speed of the flow field, and R is the gas constant. The static temperature of the incoming flow can be calculated based on the total temperature of the incoming flow and the adiabatic index and the Mach number.

[0067] Embodiment 2:

[0068] In this embodiment, the probe of the present invention is used for full-parameter measurement of the compressor outlet flow field. Since the space in the compressor outlet area is relatively large, in order to ensure the rigidity and strength of the probe, the structural size of the selected probe can be appropriately increased. The probe size is determined according to the range of each structural parameter of the probe determined by the present invention.

[0069] like Figure 7 , Figure 8 , Fig. 9 and Fig.10 As shown, this embodiment introduces a prism-shaped five-hole probe for measuring all dynamic parameters of a subsonic three-dimensional flow field, comprising a probe support rod (1), a transition section (2), a probe head (3), a pressure sensor cable (12), a temperature sensor cable (13), a heat-insulating seal (14) and a temperature sensor (15). The probe support rod (1) and the probe head (3) are both cylindrical, and the probe head (3) is connected to the probe support rod (1) through the transition section (2); the probe head (3) has a protruding prism structure, and the pressure measuring lower hole (4), the pressure measuring right hole (5), the pressure measuring left hole (6), the pressure measuring middle hole (7) and the temperature measuring hole (8) are located on the prism of the probe head (3), and the center lines of all the measuring holes are perpendicular to the prism surface where they are located. The temperature measuring hole (8) is provided with grooves (9), grooves (10) and grooves (11) on its circumference, and the pressure sensor cable (12) and the temperature sensor cable (13) are led out of the probe tail through the inner channel of the probe support rod (1).

[0070] In this embodiment, the temperature measuring hole (8) is located directly above the pressure measuring middle hole (7), the center lines of the temperature measuring right hole (5), the pressure measuring left hole (6) and the pressure measuring middle hole (7) are in the same plane, the pressure measuring lower hole (4) is located on the prism inclined surface below the pressure measuring middle hole (7), the line connecting the center of the pressure measuring lower hole (4) and the pressure measuring middle hole (7) and the line connecting the center of the pressure measuring middle hole (7) and the temperature measuring hole (8) are in the same plane, the distances from the pressure measuring right hole (5) and the pressure measuring left hole (6) to the left and right sides on the surface where they are located are equal, and the distances from the pressure measuring lower hole (4) to the upper and lower sides on the surface where it is located are equal.

[0071] In this embodiment, the diameters of the pressure measuring lower hole (4), the pressure measuring right hole (5), the pressure measuring left hole (6) and the pressure measuring middle hole (7) are the same, all 2 mm, and the inlet wall of the pressure measuring middle hole (7) adopts a bicubic curve transition; the diameter of the temperature measuring hole (8) is 3 mm, and the distance between the temperature measuring hole (8) and the pressure measuring middle hole (7) is 1.1 times the diameter of the pressure measuring middle hole (7). The slot width of the temperature measuring hole (8) is 1 / 4 of the diameter of the temperature measuring hole (8), the length of the slot on the side of the prism is 0.5 times the height of the prism, and the distance from the temperature sensor (15) to the temperature measuring hole is 0.4 times the diameter of the probe head (3).

[0072] In this embodiment, the diameter of the probe head (3) is 8 mm, the height of the protruding pyramid is 0.2 times the diameter of the probe head (3), the bottom surface of the pyramid is tangent to the cylindrical surface of the probe head (3), the length along the axial direction of the probe is 10 mm, the length of the other side of the bottom surface of the pyramid is 1 / 6 times the circumference of the probe head (3), and the angle between the side edge of the pyramid and the top surface of the pyramid is 120°.

[0073] In this embodiment, the temperature sensor (15) is located inside the cylindrical cavity of the probe head (3), and the diameter of the cylindrical cavity is 1 / 6 times the diameter of the probe head (3).

[0074] In this embodiment, the probe support rod (1) is a cylindrical structure, which plays a supporting role. A channel is opened inside the probe support rod (1), and the pressure sensor cable (12) and the temperature sensor cable (13) are led out of the probe tail through the channel inside the probe support rod (1).

[0075] In this embodiment, the temperature sensor (15) can be a thermocouple, a thermal resistor or an optical fiber temperature sensor.

[0076] Fig.11 is the profile definition diagram of the inlet section of the pressure measuring hole. The following formula is the profile curve equation of the micro-loss convergence surface used in the design of the inlet wall of the pressure measuring hole (7). The connection point x m Select 0.3.

[0077]

[0078] In the formula, R2 is the outlet radius, L is the length of the inlet section of the pressure measuring hole, R1 is the inlet radius, and x m The coordinates of the connecting point between the front and rear segments.

[0079] The present invention provides a prism five-hole probe for measuring the dynamic full parameters of the subsonic three-dimensional flow field. The probe uses the characteristics of the fluid flow around the probe, uses the pressure measuring hole on the windward side of the probe surface to measure the pressure distribution on the probe surface, uses the temperature sensor in the temperature measuring hole on the probe surface to measure the total temperature of the airflow, and then uses the calibration coefficient obtained by the standard wind tunnel calibration to calculate the full parameters of the three-dimensional flow field between the compressor stages. The specific method of use is as follows:

[0080] The probe of the present invention needs to be calibrated before use to obtain the aerodynamic calibration curve of the probe. The probe calibration is carried out in a calibration wind tunnel. Within the calibration range, the probe deflection angle and pitch angle are changed at different Mach numbers. After aerodynamic calibration, the curves of the change of each calibration coefficient with the deflection angle, pitch angle and Mach number can be obtained; the calibration coefficients include the deflection angle coefficient, pitch angle coefficient, total pressure coefficient, static pressure coefficient and temperature recovery coefficient, which are defined as follows:

[0081]

[0082]

[0083]

[0084]

[0085]

[0086] Among them, C py Deflection angle coefficient, C pp Deflection angle coefficient, C pt is the total pressure coefficient, C ps is the static pressure coefficient, C T is the temperature recovery coefficient, P t , P s and T t , T s are the total pressure, static pressure, total temperature and static temperature of the calibration wind tunnel, P1, P2, P3 and P4 are the pressure values ​​measured by the middle pressure hole, the left pressure hole, the right pressure hole and the lower pressure hole, respectively. p The temperature value measured by the temperature sensor.

[0087] like Fig.12 As shown, the flow field measured by the prism five-hole probe for measuring the dynamic full parameters of the subsonic three-dimensional flow field of the present invention is placed with the pressure measuring hole (7) facing the incoming flow direction, and the center line of the probe support rod (1) being perpendicular to the incoming flow direction. The pressure measuring hole (7) of the probe head (3) can measure the total pressure of the incoming flow, and the temperature measuring hole (8) can measure the total temperature of the incoming flow. Based on the pressures measured by the three pressure measuring holes (4), (5), and (6), combined with the known calibration coefficient curve, the deflection angle, pitch angle, total pressure, static pressure and Mach number are interpolated. The incoming flow velocity is solved according to the following formula:

[0088]

[0089]

[0090]

[0091] c 2 =γRT s

[0092] P S = ρRT S

[0093] Among them, P t and P s is the total pressure and static pressure of the flow field, γ is the adiabatic index of the flow field, T t and T s is the total temperature and static temperature of the flow field, Ma is the Mach number of the flow field, v is the flow field velocity, ρ is the density, c is the local sound speed of the flow field, and R is the gas constant.

[0094] Although the preferred embodiment has been described, various modifications or substitutions may be made to the embodiment without departing from the spirit and scope of the invention. Therefore, it should be understood that the present invention has been described in an illustrative manner rather than a restrictive manner.

Claims

1. A method for using a prism-shaped five-hole probe of subsonic three-dimensional flow field dynamic full parameters to obtain full parameters of the three-dimensional flow field between compressor stages. The structure of the prism-shaped five-hole probe of subsonic three-dimensional flow field dynamic full parameters is characterized in that: The probe comprises a probe support rod (1), a transition section (2), a probe head (3), a pressure sensor cable (12), a temperature sensor cable (13), a heat-insulating seal (14) and a temperature sensor (15); the probe support rod (1) and the probe head (3) are both cylindrical, and the probe head (3) is connected to the probe support rod (1) through the transition section (2); a protruding prism structure is provided on the probe head (3); a pressure measuring lower hole (4), a pressure measuring right hole (5), a pressure measuring left hole (6), a pressure measuring middle hole (7) and a temperature measuring hole (8) are located on the prism of the probe head (3); the center lines of all the measuring holes are perpendicular to the prism surface where they are located; a vertical groove (9), a horizontal left groove (10) and a horizontal right groove (11) are provided on the circumference of the temperature measuring hole (8); the pressure sensor cable (12) and the temperature sensor cable (13) are led out of the probe tail through the inner channel of the probe support rod (1); The temperature measuring hole (8) is located directly above the pressure measuring middle hole (7); the center lines of the pressure measuring right hole (5), the pressure measuring left hole (6) and the pressure measuring middle hole (7) are in the same plane; the pressure measuring lower hole (4) is located on the prism inclined plane below the pressure measuring middle hole (7); the line connecting the center of the pressure measuring lower hole (4) and the pressure measuring middle hole (7) and the line connecting the center of the pressure measuring middle hole (7) and the temperature measuring hole (8) are in the same plane; the distances between the pressure measuring right hole (5) and the pressure measuring left hole (6) and the left and right sides of the surface on which they are located are equal; and the distances between the pressure measuring lower hole (4) and the upper and lower sides of the surface on which they are located are equal; The diameters of the pressure measuring lower hole (4), the pressure measuring right hole (5), the pressure measuring left hole (6) and the pressure measuring middle hole (7) are the same, all of which are 0.2 to 2 mm. The inlet wall of the pressure measuring middle hole (7) adopts a smooth transition with a micro-loss convergent surface; the diameter of the temperature measuring hole (8) is 0.3 to 5 mm, the spacing between the temperature measuring hole (8) and the pressure measuring middle hole (7) is 1.1 to 1.2 times the diameter of the pressure measuring middle hole (7), the slot width of the temperature measuring hole (8) is 1 / 4 of the diameter of the temperature measuring hole (8), the length of the slot on the side of the prism is 0.5 to 0.6 times the height of the prism, and the distance from the temperature sensor (15) to the temperature measuring hole is 0.4 to 0.5 times the diameter of the probe; The height of the protruding pyramid is 0.2 to 0.3 times the diameter of the probe, the bottom surface of the pyramid is tangent to the cylindrical surface of the probe head, the length along the axial direction of the probe is 5 to 10 mm, the length of the other side of the bottom surface of the pyramid is 1 / 8 to 1 / 6 times the circumference of the probe head, and the angle between the side edge of the pyramid and the top surface of the pyramid is 120 to 150°; The temperature sensor (15) is located inside the cylindrical cavity of the probe head, and the diameter of the cylindrical cavity is 1 / 6 to 1 / 5 times the diameter of the probe head; The probe support rod (1) is a cylindrical structure and plays a supporting role. A channel is opened inside the probe support rod (1). The pressure sensor cable (12) and the temperature sensor cable (13) are led out of the probe tail through the channel inside the probe support rod (1). The diameter of the probe support rod (1) is 6-8 mm. The temperature sensor (15) may be a thermocouple, a thermal resistor or an optical fiber temperature sensor; The use steps are as follows: the first step is to calibrate the probe to obtain an aerodynamic calibration curve of the probe, wherein the probe calibration is performed in a calibration wind tunnel, and within the calibration range, the probe deflection angle and pitch angle are changed at different Mach numbers, and a curve of changes of each calibration coefficient with the deflection angle, pitch angle and Mach number can be obtained through aerodynamic calibration; Step 2: Place a subsonic three-dimensional flow field dynamic full-parameter prism five-hole probe in the flow field to be measured, with the pressure measuring middle hole (7) facing the incoming flow direction and the center line of the probe support rod (1) perpendicular to the incoming flow direction; the pressure measuring middle hole (7) at the probe head can measure the total pressure of the incoming flow, and the temperature measuring hole (8) can measure the total temperature of the incoming flow. Based on the pressures measured by the three pressure measuring holes, namely the pressure measuring lower hole (4), the pressure measuring right hole (5) and the pressure measuring left hole (6), combined with a known calibration coefficient curve, the deflection angle, pitch angle, total pressure, static pressure and Mach number are interpolated.

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