A five-hole probe rotating measurement device for an inlet wind tunnel test

Abstract

The application discloses an air inlet duct wind tunnel test five-hole probe rotation measuring device, and belongs to the field of wind tunnel test. The device comprises a driving motor, a rotation measuring section, a front end and a rear end static connection section, four five-hole probe measuring rakes and one dynamic pressure measuring rake. The rotation measuring section is internally provided with a center cone. The front end static connection section and the rear end static connection section are respectively connected with the rotation measuring section through Gley rings to realize sealing of the dynamic and static interface. The driving motor drives the rotation measuring section to rotate. The target seats of the four five-hole probe measuring rakes and the one dynamic pressure measuring rake are fixed on the outer side wall of the rotation measuring section. The front of the rotation measuring section is a circular measuring surface. The measuring ends of the four five-hole probe measuring rakes are located on the measuring surface and are arranged in a cross shape, which is used for measuring the steady-state pressure and velocity distribution of the air inlet duct. The rotation measuring device only needs one circumferential degree of freedom, and the performance measurement of the measuring section can be realized. The device has the advantages of high positioning precision, good overall sealing performance, simple structure and easy realization.

Description

Technical Field

[0001] This invention belongs to the field of wind tunnel testing, specifically relating to a five-hole probe rotating measurement device for air intake wind tunnel testing. Background Technology

[0002] The air intake is the interface component connecting the aircraft and the engine, playing a crucial role in aircraft performance. From design to use, the air intake process requires sequential testing: air intake model wind tunnel testing, engine ground distortion simulation testing, air intake / engine ground compatibility testing, and flight testing. Among these, air intake model wind tunnel testing is fundamental and a prerequisite. Currently, in air intake model wind tunnel testing, performance evaluation primarily relies on pressure gauges. The number and arrangement of these gauges are generally determined by the engine manufacturer, typically using a five-hole probe measuring gauge with two gauges at a 45° or 60° angle. With increasing requirements for aircraft flight testing, new demands have been placed on the volume and precision of air intake test data. Existing rotating measuring sections are complex and prone to obstruction. Summary of the Invention

[0003] Based on the above shortcomings, the purpose of this invention is to provide a five-hole probe rotating measurement device for air intake wind tunnel testing, which solves the problems of complex structure and high blockage of existing measurement devices.

[0004] The technical solution adopted in this invention is as follows: A five-hole probe rotating measurement device for air intake duct wind tunnel testing includes a drive motor, a rotating measurement section, a front stationary connecting section, a rear stationary connecting section, four five-hole probe measuring rakes, and one dynamic pressure measuring rake. The front stationary connecting section and the rear stationary connecting section are axially fixedly connected by multiple support rods. The front stationary connecting section is connected to the outlet of the test air intake duct model, and the rear stationary connecting section is connected to the air intake duct test suction pipeline. The rotating measurement section has a central cone inside. The front end of the rotating measurement section is inserted into the inner cavity of the front stationary connecting section, and the rear end of the rotating measurement section is inserted into the inner cavity of the rear stationary connecting section. The front stationary connecting section and the rear stationary connecting section are respectively sealed at the dynamic and static interface with the rotating measurement section through Glyd rings. The drive motor is fixedly connected to the rear stationary connecting section through a motor connector. The power output shaft of the drive motor is connected to the drive gear through a key. The outer surface of the rotating measurement section... A ring-shaped driven tooth is fixedly connected to the wall, and the ring-shaped driven tooth meshes with the drive gear, thereby driving the rotating measuring section to rotate. The target seats of the four five-hole probe measuring rakes and one dynamic pressure measuring rake are all fixed on the outer wall of the rotating measuring section. In front of the rotating measuring section is a circular measuring surface, the radius of which is the same as the inner diameter of the rotating measuring section. The measuring ends of the four five-hole probe measuring rakes are all located on the measuring surface and arranged in a "+" shape, used to measure the steady-state pressure and velocity distribution of the intake duct. A dynamic pressure measuring rake is arranged on the bisector of the mid-angle between two adjacent five-hole probe measuring rakes, and the measuring end of the dynamic pressure measuring rake is also located on the measuring surface, used to measure the dynamic pressure of the intake duct. When the rotating measuring device is working, it only requires one circumferential degree of freedom. It measures once for each circumferential rotation angle. The data obtained from each angle within the ±180° rotation range constitutes the intake duct measurement section data for that state.

[0005] Furthermore, the radial positions of the measuring ends of the four five-hole probes are distributed according to equal-area rings, with the radius R of the equal-area rings being... i The calculation formula is as follows:

[0006]

[0007] In the formula: R is the inner diameter of the rotating measurement section, r is the radius of the central cone, n is the total number of rings of the measurement points, n = 4, i = 1, 2, 3, 4.

[0008] Furthermore, the radial length from the measuring end of the dynamic pressure measuring rake to the central axis of the rotating measuring section is 90% of the inner diameter length of the rotating measuring section.

[0009] Furthermore, the target seats of the four five-hole probe measuring rakes and the dynamic pressure measuring rake are staggered along the flow direction on the side wall of the rotating measuring section to reduce the blockage at the same cross section.

[0010] Furthermore, the present invention also includes a magnetic ring, a zero-point position identification device, and a magnetic ring encoder. A magnetic ring is fixedly connected to the outer wall of the rotating measuring section, and a zero-point positioning marker is installed on the magnetic ring. The zero-point position identification device is fixed on a support rod. When the measuring end of the zero-point position identification device coincides with the zero-point positioning marker, it provides feedback on the initial zero position of the rotating measuring section. The magnetic ring encoder is fixedly connected to the rear stationary connecting section. The reading head of the magnetic ring encoder is located above the magnetic ring and is used to record the angle value rotated by the rotating measuring section.

[0011] Another objective of this invention is to provide a measurement method derived from the five-hole probe rotating measuring device for inlet wind tunnel testing described above, as follows: During the test, the rotating measuring device is rotated counterclockwise to a position 180° relative to the zero mark and waits. The wind tunnel is then energized to the test wind speed. After the wind speed stabilizes, the inlet begins to draw air in. Once the flow field inside the inlet reaches a stable state, the rotating measuring device begins to operate. First, it collects data at the 180° relative zero position. After data collection, it rotates clockwise at certain angular intervals according to the test requirements. After reaching the designated angular position, it waits for 5 seconds to collect data at that position. After data collection, it continues to rotate to the next angular position, repeating the above process until all angular positions are collected. Within a range of ±180°, the data obtained at each position constitutes the inlet inlet matching section performance data under that state, including steady-state and dynamic pressure distribution and velocity distribution.

[0012] Furthermore, using the measurement method described above, the pressure at the five orifices was measured, and the total pressure, static pressure, Mach number, and velocity direction at the measuring points were calculated. Then, based on the velocity components in the three directions and the swirl angle at the given velocity, the calculation formulas are as follows:

[0013] Vx=Vcosβcosα

[0014] Vy=Vsinβ

[0015] Vz=Vcosβsinα

[0016] θ = Vy / Vx = tgβcosα

[0017] In the formula, V, Vx, Vy, and Vz are the velocity components in three directions of the current velocity calculated based on the Mach number, α and β are the angle of attack and sideslip angle measured by the measuring device, and θ is the swirl angle, whose direction is defined according to the actual situation. It is positive if it is consistent with the rotation direction of the propeller or fan, and negative if it is opposite.

[0018] The advantages and beneficial effects of this invention are as follows: This measuring device can obtain high-density pressure and velocity data of the inlet matching section of the air intake, requiring only one circumferential degree of freedom to achieve the measurement of the cross-sectional performance. It has the advantages of high positioning accuracy, good overall sealing, simple structure, and ease of implementation. It can simultaneously measure the steady-state and dynamic pressure and velocity within the air intake, and can flexibly change and densify the measurement positions according to experimental requirements, increasing the amount of information and flexibility of data obtained from air intake wind tunnel tests. Attached Figure Description

[0019] Figure 1 This is the main view of the invention. Figure 1 ;

[0020] Figure 2 This is a perspective view of the external structure of the present invention;

[0021] Figure 3 for Figure 1 The view after rotating by a certain angle;

[0022] Figure 4 for Figure 3 Sectional view at position AA;

[0023] Figure 5 This is a cross-sectional view showing the positions of the measuring ends of the five measuring rakes located on the measuring surface;

[0024] Figure 6 A coordinate system diagram for probe calibration;

[0025] Figure 7 Diagram of the probe measurement coordinate system;

[0026] Figure 8 Cloud maps of total pressure recovery coefficients for four different angle intervals of the rotating rake intake cross-section;

[0027] Figure 9 Swirl angle cloud diagrams of the measurement cross sections of the air intake at four different angle intervals for the rotating rake.

[0028] Among them, 1. First five-hole probe measuring rake, 2. Second five-hole probe measuring rake, 3. Third five-hole probe measuring rake, 4. Fourth five-hole probe measuring rake, 5. Dynamic pressure measuring rake, 6. Drive motor, 7. Drive gear, 8. Motor connector, 9. Rear stationary connecting section, 10. Annular driven tooth, 11. Magnetic ring, 12. Zero point positioning block, 13. Support rod, 14. Magnetic ring encoder, 15. Zero point position identification device, 16. Rotary measuring section, 17. Front stationary connecting section, 18. Five-hole probe measuring rake seat, 19. Dynamic pressure measuring rake seat, 20. Rear Glyd ring, 21. Front Glyd ring, 22. Central cone. Detailed Implementation

[0029] The following specific implementation examples, in conjunction with the accompanying drawings, further illustrate the technical solution of the present invention.

[0030] Example 1

[0031] like Figure 1-4 As shown, a five-hole probe rotating measurement device for an air intake wind tunnel test includes a drive motor 6, a rotating measurement section 16, a front stationary connecting section 17, a rear stationary connecting section 9, a first five-hole probe measuring rake 1, a second five-hole probe measuring rake 2, a third five-hole probe measuring rake 3, a fourth five-hole probe measuring rake 4, and a dynamic pressure measuring rake 5. The front stationary connecting section 17 and the rear stationary connecting section 9 are fixedly connected by four support rods 13. The front stationary connecting section 17 is connected to the outlet of the test air intake model, and the rear stationary connecting section 9 is connected to... The intake duct test suction line is connected. The rotating measuring section 16 has a central cone 22 inside. The front end of the rotating measuring section 16 is inserted into the inner cavity of the front stationary connecting section 17, and the rear end of the rotating measuring section 16 is inserted into the inner cavity of the rear stationary connecting section 9. The front stationary connecting section 17 and the rear stationary connecting section 9 are sealed to the dynamic and static interfaces of the rotating measuring section 16 by the front Glyd ring 21 and the rear Glyd ring 20, respectively. The drive motor 6 is fixedly connected to the rear stationary connecting section 9 through the motor connector 8. The power of the drive motor 6 is... The output shaft is connected to the drive gear 7 via a key. An annular driven tooth 10 is fixedly connected to the outer wall of the rotating measuring section 16. The annular driven tooth 10 meshes with the drive gear 7, thereby driving the rotating measuring section 16 to rotate. The target seats of the four five-hole probe measuring rakes and one dynamic pressure measuring rake are all fixed to the outer wall of the rotating measuring section 16. A circular measuring surface is located in front of the rotating measuring section 16, with a radius equal to the inner diameter of the rotating measuring section 16. The measuring ends of the four five-hole probe measuring rakes are all located at the measuring... The measuring surface is arranged in a cross shape to measure the steady-state pressure and velocity distribution of the intake duct. A dynamic pressure measuring rake 5 is arranged on the bisector of the angle between the third five-hole probe measuring rake 3 and the fourth five-hole probe measuring rake 4. The measuring end of the dynamic pressure measuring rake 5 is also located on the measuring surface to measure the dynamic pressure of the intake duct. When the rotating measuring device is working, it only needs one circumferential degree of freedom. It measures once for each circumferential rotation angle. The data obtained from each angle within the ±180° rotation range constitute the intake duct measurement cross-sectional data for that state.

[0032] like Figure 5 As shown, the radial positions of the measuring ends of the four five-hole probes are distributed according to equal-area rings, with the radius R of the equal-area rings being... i The calculation formula is as follows:

[0033]

[0034] In the formula: R is the inner diameter of the rotating measurement section, r is the radius of the central cone, n is the total number of rings of the measurement points, n = 4, i = 1, 2, 3, 4.

[0035] The radial length from the measuring end of the dynamic pressure measuring rake 5 to the central axis of the rotating measuring section 16 is 90% of the inner diameter length of the intermediate rotating section.

[0036] like Figure 2 , 4 As shown, the target seats of the four five-hole probe measuring rakes and the dynamic pressure measuring rake are staggered along the flow direction on the side wall of the middle rotating section to reduce the blockage of the same cross section.

[0037] The rotating measuring device of this embodiment also includes a magnetic ring 11, a zero-point position identification device 15, and a magnetic ring encoder 14. The outer wall of the rotating measuring section 16 is fixedly connected to the magnetic ring 11, and a zero-point positioning marker 12 is installed on the magnetic ring 11. The zero-point position identification device 15 is fixed on any support rod 13. When the measuring end of the zero-point position identification device 15 coincides with the zero-point positioning marker 12, it feeds back the initial zero position of the rotating measuring section 16. The magnetic ring encoder 14 is fixedly connected to the rear stationary connecting section 9. The reading head of the magnetic ring encoder 14 is located above the magnetic ring 11 and is used to record the angle value rotated by the intermediate rotating section. This implements high-precision closed-loop control for the measuring device, with an angle rotation accuracy within 3′. The zero-point position identification device 15 ensures that the position can still be accurately marked after power failure and restart.

[0038] like Figure 6-7 As shown, the total pressure, static pressure, Mach number, and velocity direction at the measuring point are calculated using the pressure measured by the above measuring device. Then, the calculation formulas for the velocity components in the three directions and the swirl angle at the given velocity are as follows:

[0039] Vx=Vcosβcosα

[0040] Vy=Vsinβ

[0041] Vz=Vcosβsinα

[0042] θ = Vy / Vx = tgβcosα

[0043] In the formula, V, Vx, Vy, and Vz are the velocity components in three directions of the current velocity calculated based on the Mach number, α and β are the angle of attack and sideslip angle measured by the measuring device, and θ is the swirl angle, whose direction is defined according to the actual situation. It is positive if it is consistent with the rotation direction of the propeller or fan, and negative if it is opposite.

[0044] During the test, the rotating measuring device was rotated counterclockwise to the position 180° relative to the zero mark and held. The wind tunnel was then ventilated to the test wind speed. After the wind speed stabilized, the intake began to draw air in. Once the flow field within the intake reached a stable state, the rotating measuring device began operation. First, it collected data at the 180° relative zero position. After data collection, it was rotated clockwise at certain angular intervals according to the test requirements. After reaching the designated angular position, it waited 5 seconds before collecting data at that position. After data collection, it continued to rotate to the next angular position, repeating the above process until data collection was completed at all angular positions. Within a range of ±180°, the data obtained from each position constituted the intake duct inlet matching section performance data for that state, including steady-state and dynamic pressure distribution and velocity distribution. Figure 8-9 As shown, the total pressure recovery coefficient cloud map and the swirl angle cloud map of the inlet measurement section at four different angle intervals can obtain high-density pressure and velocity data of the inlet inlet matching section. The amount of data is much greater than that of conventional fixed total pressure rakes, providing a new measurement method for aircraft inlet performance evaluation. The measurement accuracy of the rotating measuring device has been verified to meet the requirements of inlet testing.

Claims

1. A five-hole probe rotating measurement device for air intake wind tunnel testing, comprising a drive motor, a rotating measurement section, a front stationary connecting section, a rear stationary connecting section, four five-hole probe measuring rakes, and one dynamic pressure measuring rake, characterized in that: The front stationary connecting section and the rear stationary connecting section are fixedly connected by multiple support rods. The front stationary connecting section is connected to the outlet of the test air intake model, and the rear stationary connecting section is connected to the test suction pipeline of the air intake. The rotating measuring section has a central cone inside. The front end of the rotating measuring section is inserted into the inner cavity of the front stationary connecting section, and the rear end of the rotating measuring section is inserted into the inner cavity of the rear stationary connecting section. The front and rear stationary connecting sections are sealed to the rotating measuring section via Gladley rings to achieve dynamic and static interface sealing. The drive motor is fixedly connected to the rear stationary connecting section via a motor connector. The power output shaft of the drive motor is connected to the drive gear via a key. An annular driven tooth is fixedly connected to the outer wall of the rotating measuring section. The annular driven tooth meshes with the drive gear, thereby driving the rotating measuring section to rotate. Four five-hole probe measuring rakes and one dynamic pressure... The target mounts of the force measuring rakes are all fixed on the outer wall of the rotating measuring section. A circular measuring surface is located in front of the rotating measuring section, with a radius equal to the inner diameter of the rotating measuring section. The measuring ends of the four five-hole probe measuring rakes are all located on this measuring surface and arranged in a cross shape for measuring the steady-state pressure and velocity distribution of the air intake. A dynamic pressure measuring rake is arranged on the bisector of the angle between two adjacent five-hole probe measuring rakes, with its measuring end also located on the measuring surface for measuring the dynamic pressure of the air intake. When the rotating measuring device is working, it only requires one circumferential degree of freedom. Measurements are taken once for each circumferential rotation angle. The data obtained from each angle within a ±180° rotation range constitute the state air intake measurement section data. The radial positions of the measuring ends of the four five-hole probe measuring rakes are distributed according to an equal-area ring with a radius R. i The calculation formula is as follows: ， In the formula: R is the inner diameter of the rotating measurement section, r is the radius of the central cone, n is the total number of rings of the measurement points, n=4, i=1,2,3,4.

2. The five-hole probe rotating measuring device for air intake duct wind tunnel testing according to claim 1, characterized in that: The radial length from the measuring end of the dynamic pressure measuring rake to the central axis of the rotating measuring section is 90% of the inner diameter of the rotating measuring section.

3. The five-hole probe rotating measuring device for air intake duct wind tunnel testing according to claim 2, characterized in that: The target mounts of the four five-hole probe measuring rakes and the dynamic pressure measuring rake are staggered along the flow direction on the side wall of the rotating measuring section to reduce the blockage at the same cross section.

4. The five-hole probe rotating measuring device for air intake duct wind tunnel testing according to any one of claims 1-3, characterized in that: It also includes a magnetic ring, a zero-point position identification device, and a magnetic ring encoder. The outer wall of the rotating measuring section is fixedly connected to a magnetic ring, and a zero-point positioning marker is installed on the magnetic ring. The zero-point position identification device is fixed on a support rod. When the measuring end of the zero-point position identification device coincides with the zero-point positioning marker, it feeds back the initial zero position of the rotating measuring section. The magnetic ring encoder is fixedly connected to the rear stationary connecting section. The reading head of the magnetic ring encoder is located above the magnetic ring and is used to record the angle value rotated by the rotating measuring section.

5. A measurement method derived from the five-hole probe rotating measuring device for air intake wind tunnel testing according to claim 4, characterized in that, The method is as follows: During the test, the rotating measuring device is rotated counterclockwise to the position 180° relative to the zero mark and waits. The wind tunnel is turned on to the test wind speed. After the wind speed stabilizes, the air intake begins to draw in air. After the flow field in the air intake reaches a stable state, the rotating measuring device starts to work. First, it collects data at the 180° relative zero position. After the data collection is completed, it is rotated clockwise at certain angle intervals according to the test requirements. After reaching the specified angle position, it waits for 5 seconds to collect data at that position. After the data collection is completed, it continues to rotate to the next angle position. The above process is repeated until all angle positions are collected. The data obtained by the rotating measuring device at each position within the ±180° range constitutes the air intake inlet matching section performance data under that state, including steady-state and dynamic pressure distribution and velocity distribution.

6. The measurement method according to claim 5, characterized in that: By measuring the pressure, the total pressure, static pressure, Mach number, and velocity direction at the measuring point are calculated. Then, based on the velocity components in the three directions and the swirl angle at the given velocity, the calculation formulas are as follows: ， ， ， ， In the formula, V, Vx, Vy, and Vz are the velocity components in the three directions at the given current velocity calculated based on the Mach number. and These are the angle of attack and sideslip angle measured by the measuring device. It is the swirl angle, and its direction is defined according to the actual situation. It is positive if it is in the same direction as the rotation of the propeller or fan, and negative if it is opposite.

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