Double-helix twelve-hole water-cooling dynamic pressure probe for measuring two-dimensional parameters of backflow flow field of combustion chamber in wide range

Abstract

The invention belongs to the technical field of high-temperature flow field pressure testing, and discloses a double-helix twelve-hole water-cooling dynamic pressure probe for measuring two-dimensional parameters of a backflow flow field of a combustion chamber in a wide range, which is characterized by comprising a probe head, a support rod and a special double-helix cooling structure inside the support rod. The probe head comprises twelve pressure sensing holes formed in the side face, and twelve dynamic pressure sensors are packaged in the holes. Cooling water in the water inlet channel flows into the water outlet channel under the action of the partition plate, centrifugal force and pressure difference. The twelve pressure sensing holes are distributed on the side surface of the probe head in a three-layer staggered manner and are led out from the middle of the inner and outer spiral cooling water channels. After calibration of a calibration wind tunnel, three-dimensional flow parameters such as the deflection angle, the total pressure, the static pressure and the Mach number in a backflow flow field of the combustion chamber can be measured without a displacement mechanism. Compared with an existing water-cooling probe, the probe can realize flow field measurement in a higher-temperature environment, and is higher in structural strength and wider in measurement range.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-temperature pressure testing, and relates to a dynamic pressure measurement device for a two-dimensional flow field. Specifically, it relates to a water-cooled pressure probe for measuring a two-dimensional dynamic high-temperature flow field with recirculation in a combustion chamber, which is applicable to measuring the circumferential distribution of two-dimensional flow parameters such as pitch angle, yaw angle, total pressure, static pressure, and Mach number in a two-dimensional flow field with recirculation in a combustion chamber. Background Art

[0002] The combustion chamber of an aeroengine is one of the core components of the engine. The high-temperature and high-pressure environment inside it plays a decisive role in the performance, efficiency, and safety of the engine. The pressure distribution and dynamic changes inside the combustion chamber are directly related to the combustion efficiency of fuel, thrust output, thermal efficiency, and the stable operation of the engine. Accurately measuring the high-temperature pressure inside the combustion chamber is crucial for optimizing the combustion process, improving engine performance, reducing fuel consumption, reducing pollutant emissions, and ensuring the reliability and lifespan of the engine. During the combustion chamber design stage, the structure and fuel injection strategy of the combustion chamber can be optimized through precise pressure measurement. During the engine operation process, real-time monitoring of the combustion chamber pressure helps to promptly detect abnormal combustion phenomena such as knocking and combustion instability, so as to take corresponding measures to avoid engine damage.

[0003] However, the temperature inside the combustion chamber is extremely high, usually reaching 1500°C - 2000°C, which makes it difficult for traditional pressure measurement sensors to withstand, easily resulting in a decline in the material performance of the sensor, obstruction of signal transmission, or even damage. Secondly, the pressure inside the combustion chamber is usually between several megapascals and dozens of megapascals, requiring the measuring device to have extremely high strength and precision, while ensuring stability and reliability under high-pressure conditions. Moreover, the gas flow velocity inside the combustion chamber is high, the turbulence is intense, and there are complex chemical reactions and combustion products. These factors will interfere with pressure measurement, increasing the difficulty and error of measurement. At the same time, the high-temperature environment inside the combustion chamber will cause the generation of corrosive gases such as sulfur dioxide and sulfur trioxide. These gases will corrode the surface and internal structure of the measuring device, affecting the measurement accuracy and the lifespan of the device.

[0004] Common pressure measurement methods, such as the PSP (Pressure Sensitive Paint) test technology, have high requirements for the optical path layout, and their test objects are often the pressures on the surface of the object to be measured, making it difficult to meet the requirements for measuring the internal flow field in the combustion chamber. Fiber optic pressure sensors are based on fiber optic sensing technology and have advantages such as high temperature resistance, electromagnetic interference resistance, and small size. However, they still face problems such as high cost and limited measurement range. The materials of conventional pressure probes cannot withstand temperatures exceeding 1300 K, and the heads of dynamic pressure sensors cannot withstand temperatures exceeding 500 K, which causes the probes to be damaged during the measurement process and makes the measurement impossible to proceed. When measuring the three-dimensional parameters of the internal flow field with a recirculation flow field in the combustion chamber, the measurement angle range of a conventional five-hole probe is about ±15°, making it difficult to meet the measurement requirements in such a complex internal flow environment in the combustion chamber. To solve this problem, the common practice in engineering is currently to increase the number of holes on the probe, such as seven-hole, twelve-hole, and eighteen-hole probes. However, as the number of holes increases, the diameter of the probe strut and the size of the probe head will become larger, which will not only cause more serious interference to the flow field but also make it difficult to meet the requirements for high-resolution measurement in a narrow space. Water-cooled pressure probes utilize the cooling characteristics of water to convert the pressure measurement problem in a high-temperature environment into a measurement problem at a relatively low temperature, thus effectively solving the destructive impact of high temperature on the measurement equipment. After decades of development, the water-cooled pressure probe technology has been continuously improved, and significant progress has been made in aspects such as its structural design, cooling efficiency, measurement accuracy, and reliability, becoming one of the important tools for measuring the high-temperature pressure in the combustion chamber of aeroengines.

[0005] The basic structure of a water-cooled pressure probe includes three parts: the probe head, the cooling system, and the pressure sensor. The probe head is directly exposed to the high-temperature environment in the combustion chamber and is used to collect pressure signals. The cooling system takes away the heat from the probe head through circulating water flow, reducing the temperature inside the probe to the temperature range in which the pressure sensor can work normally. The pressure sensor is installed inside the probe and reflects the actual pressure in the combustion chamber by measuring the cooled pressure signal. The working principle of the water-cooled pressure probe can be summarized as: utilizing the high specific heat capacity and good thermal conductivity of water to quickly transfer the heat in the high-temperature environment to the outside, thereby protecting the internal pressure sensor from being damaged by high temperature and ensuring the accuracy and stability of the measurement signal.

[0006] It is not easy to make the size of a dynamic pressure probe small. A large size will seriously interfere with the measured flow field. On the other hand, the cost of dynamic pressure probes is too high. For existing probes with a water-cooled structure (patent for invention: A water-cooled probe, 2017207630951), cooling water is introduced through one water inlet, and uneven water inlet may occur, which may lead to the consequence of local ablation of the probe.

[0007] The existing water-cooled pressure probes capable of measuring the dynamic parameters of three-dimensional flow fields (invention patent: A water-cooled pressure probe for measuring the three-dimensional dynamic high-temperature flow field between turbine stages, 2024109924174) are mainly applied to the measurement of three-dimensional dynamic high-temperature flow field parameters between turbine stages and cannot achieve the measurement of two-dimensional dynamic parameters of the high-temperature flow field with recirculation in the combustion chamber. The existing water-cooled pressure probes for measuring the flow field with recirculation in the combustion chamber (invention patent: An omnidirectional four-hole water-cooled dynamic pressure probe for measuring the recirculation flow field in the combustion chamber, 2024109925656) can measure the recirculation phenomenon in the aero-engine combustion chamber. However, due to the circumferential four-hole arrangement of this probe, the spatial resolution is relatively low, and the measurement range is relatively narrow.

[0008] Existing water-cooled pressure probes are difficult to meet the test requirements for measuring the two-dimensional dynamic high-temperature flow field with recirculation in the combustion chamber, especially at an extremely high temperature of 2500K. Therefore, there is an urgent need for a water-cooled dynamic pressure probe that is suitable for high temperature resistance, prevents local ablation, and can achieve a wide-range measurement of two-dimensional flow field parameters with recirculation in the combustion chamber. Summary of the Invention

[0009] The technical problem to be solved by the present invention is: Aiming at the test requirements that the existing pressure probes cannot meet for measuring the two-dimensional dynamic high-temperature flow field with recirculation in the combustion chamber, especially the two-dimensional dynamic flow field test requirements at an extremely high temperature of 2500K, invent a water-cooled dynamic pressure probe with high temperature resistance and capable of measuring the two-dimensional dynamic flow field parameters with recirculation in the combustion chamber.

[0010] The temperature in the combustion chamber is extremely high, usually reaching above 1500°C. The probe needs to select materials that can maintain structural stability at such high temperatures and do not undergo material property degradation (such as strength reduction, deformation, melting, etc.). For example, although common superalloys are heat-resistant to a certain extent, they may still have problems such as creep under long-term high-temperature exposure. When measuring the dynamic parameters of the two-dimensional high-temperature flow field with recirculation in the combustion chamber, the surrounding environment temperature is very high, and the excessive temperature will damage the probe. Therefore, a cooling measure needs to be taken to reduce the temperature around the probe strut. At the same time, due to the recirculation phenomenon in the aero-engine combustion chamber flow field, it is necessary to design a dynamic pressure probe with a special cooling structure that can measure the two-dimensional dynamic parameters of the high-temperature flow field with recirculation in the aero-engine combustion chamber.

[0011] In addition to the temperature resistance of the material itself, an effective thermal protection structure also needs to be designed. Water cooling is one of the key means, but how to ensure that the cooling water can continuously and uniformly cool the probe in a high-temperature environment, while preventing cooling failure caused by cooling water leakage or vaporization is a major challenge. For example, the design of the cooling water channel needs to consider the uniform distribution of water flow, reasonable control of flow velocity, and sealing performance to prevent high-temperature gas from entering the cooling water channel and affecting the cooling effect.

[0012] To measure the dynamic parameters of a recirculation flow field, multiple sensors need to be arranged on the probe to measure parameters such as pressure, temperature, and flow velocity in different directions respectively. The layout of these sensors needs to be reasonable, covering the entire circumferential space without interfering with each other. For example, the installation position of the pressure sensor will affect the measurement accuracy. If installed in the eddy current or recirculation area, it may cause large fluctuations in the measured values. In addition, the recirculation flow field in the combustion chamber will generate complex aerodynamic forces, and the probe needs to have sufficient structural strength to resist these forces and prevent deformation or damage. For example, the gas flow velocity in the recirculation area may be very high, generating a large impact force on the windward surface of the probe, and it is necessary to optimize the shape and structure of the probe to reduce the influence of this force. The parameter changes of the recirculation flow field are very fast, and the probe needs to have a wide measurement range and fast dynamic response ability. For example, the pressure may fluctuate rapidly in the recirculation area. If the dynamic response speed of the probe is not fast enough, these changes cannot be accurately captured, thus affecting the accuracy of the measurement results.

[0013] To this end, the present invention provides a double - helix twelve - hole water - cooled dynamic pressure probe for measuring two - dimensional parameters of the recirculation flow field in an aero - engine combustion chamber. During measurement, cooling water is introduced into the water inlet of the probe. After the cooling water flows through the interior of the probe, it is discharged through the drain outlet. The water inlet channel located in the inner helix and the water outlet channel located in the outer helix are interconnected through the probe head and complete the transition under the action of centrifugal force and the partition plate. When actually measuring the dynamic parameters of the aero - engine combustion chamber with a recirculation flow field, the central axes of the twelve pressure - sensing holes are perpendicular to the gas flow direction. Since the pressure - sensing holes adopt a three - layer arrangement, the pressure measurement values of any three holes can be regarded as the pressure values obtained by a three - hole pressure probe. Compared with the existing structure, the double - helix water flow channel structure can avoid the situation of excessive local pressure loss of the cooling water, ensure the uniform distribution of the water flow and the reasonable control of the flow velocity. At the same time, the design of separating the inner and outer helices for the entire water flow channel can balance the stress on the probe housing while ensuring the overall cooling effect of the probe. The cooling water from the water inlet channel located in the inner helix is transferred to the water outlet channel located in the outer helix by centrifugal force and is finally discharged through the water outlet of the water outlet channel at the tail of the probe strut. The twelve pressure - sensing holes arranged at the probe head can achieve real - time measurement of the two - dimensional dynamic parameters of the high - temperature flow field with recirculation. At the same time, the special double - helix cooling structure enables the probe to have stronger high - temperature resistance and is more suitable for measuring the flow field of the aero - engine combustion chamber. When actually measuring the two - dimensional recirculation flow field of the combustion chamber, the central axis of the probe head of this water - cooled dynamic pressure probe is perpendicular to the gas flow direction. By combining the data measured by multiple pressure - sensing holes and using the calibration wind tunnel calibration data obtained for data processing, two - dimensional flow parameters such as the deflection angle, total pressure, static pressure, and Mach number in the two - dimensional recirculation flow field of the aero - engine combustion chamber can be obtained. After introducing the cooling water, it is possible to measure the flow field parameters in a high - temperature environment of 2500K, and the frequency response of this probe exceeds 25kHz.

[0014] The solution of the present invention is:

[0015] 1. A double - helix twelve - hole water - cooled dynamic pressure probe for measuring two - dimensional parameters of the recirculation flow field in a combustion chamber over a wide range, mainly composed of a probe head (1), a probe rod (2), pressure - sensing holes (3), (4), (5), (6) on the top layer of the probe head, pressure - sensing holes (7), (8), (9), (10) in the middle layer of the probe head, pressure - sensing holes (11), (12), (13), (14) on the bottom layer of the probe head, a wire - passing cavity (15), a partition plate (16), four water - inlet channels (17), (18), (19), (20) and four water - outlet channels (21), (22), (23), (24). It is characterized in that: the probe head (1) has a cylindrical shape, with a diameter of 10 mm to 30 mm and a length of 20 mm to 80 mm. The probe head (1) and the shell of the probe rod (2) are both made of Inconel alloy material, and their surfaces are both coated with high - temperature heat - insulating coatings.

[0016] 2. Further, the pressure - measuring holes are divided into top - layer, middle - layer and bottom - layer, and are arranged circumferentially in a staggered manner on the side of the probe head (1). Their aperture is 0.5 mm to 2 mm. The distance from the center line of the four pressure - sensing holes (3), (4), (5), (6) on the top layer of the probe head to the upper surface of the probe head (1) is 3 mm to 10 mm. The plane where the central axes of the four pressure - sensing holes (7), (8), (9), (10) in the middle layer of the probe head are located is 1 mm to 5 mm away from the plane where the central axes of the four pressure - sensing holes (2), (3), (4), (5), (6) on the top layer of the probe head are located. And the angle between the plane where the central axis of the middle - layer pressure - sensing hole and the central axis of the probe head and the plane where the central axis of the top - layer pressure - sensing hole and the central axis of the probe head is 45°. The four pressure - sensing holes (11), (12), (13), (14) on the bottom layer of the probe head are respectively located directly below the four pressure - sensing holes (3), (4), (5), (6) on the top layer of the probe head, and the distance between the plane where the central axes of the four pressure - sensing holes on the top layer are located and the plane where the central axes of the four pressure - sensing holes on the bottom layer are located is 6 mm to 20 mm.

[0017] 3. Further, the pressure sensor is located at the connection of each pressure - sensing hole and the wire - passing cavity (15). The wire is led out through the outlet of the wire - passing cavity (15) at the tail of the probe rod (2), connected to a micro - pressure transmitter and then to the test module. The diameter of the wire - passing cavity (15) is 2 mm to 5 mm. The measurement accuracy of the pressure sensor is 0.1% to 0.5%, and the natural frequency is 100 Hz to 300 KHz.

[0018] 4. Further, the water inlet system inside the probe consists of four water inlet channels (17), (18), (19), and (20). Each water inlet channel is located in the inner layer helix and converges at the top of the probe head (1) with four water outlet channels (21), (22), (23), and (24). The diameter of each water inlet channel is 0.5 mm to 5 mm. A straight pipe with internal threads is provided at the inlet of each of the four water inlet channels (17), (18), (19), and (20). The central axes of the four straight pipes are smoothly transitioned with the helical lines of the corresponding water inlet channels to reduce flow losses. The length of the straight pipe is 1 mm to 8 mm.

[0019] 5. Further, the water outlet system inside the probe consists of four water outlet channels (21), (22), (23), and (24). Each water outlet channel is located in the outer layer helix. A straight pipe with external threads is provided at the outlet of each of the four water outlet channels (21), (22), (23), and (24). The central axes of the four straight pipes are smoothly transitioned with the helical lines of the corresponding water outlet channels to reduce flow losses. The length of the straight pipe is 1 mm to 10 mm.

[0020] 6. Further, the central lines of the four water inlet channels (17), (18), (19), and (20) and the four water outlet channels (21), (22), (23), and (24) inside the probe all adopt a variable pitch design to ensure smoother flow of the cooling water. The pitch is 2 mm to 20 mm.

[0021] In the present invention, a double - helix twelve - hole water - cooled dynamic pressure probe for wide - range measurement of two - dimensional parameters of the combustion chamber recirculation flow field can obtain calibration data through calibration in a wind tunnel. When actually measuring the two - dimensional recirculation flow field of an aero - engine combustion chamber, the central axis of the probe head of this water - cooled dynamic pressure probe is perpendicular to the gas flow direction. By using the obtained calibration data from the calibration wind tunnel for data processing, two - dimensional flow parameters such as the deflection angle, total pressure, static pressure, and Mach number in the two - dimensional recirculation flow field of the aero - engine combustion chamber can be obtained. After cooling water is introduced, it is possible to measure the flow field parameters in a high - temperature environment of 2500K, and the probe can penetrate into the flow field by 80 mm to 200 mm.

[0022] The present invention, a double - helix twelve - hole water - cooled dynamic pressure probe for wide - range measurement of two - dimensional parameters of the combustion chamber recirculation flow field, has the following beneficial effects:

[0023] Beneficial effect 1: The probe can achieve measurements in high-temperature environments. After being calibrated in a calibration wind tunnel, the present invention can be used to measure two-dimensional flow field parameters such as total pressure, static pressure, deflection angle, Mach number, etc. inside the combustion chamber of an aeroengine with a recirculation flow field, providing measured data for improving the performance of the aeroengine combustion chamber. Compared with conventional measurement probes, this probe can achieve measurements in high-temperature environments. After injecting cooling water, the cooling effect around the sensing part of the probe is enhanced, reducing the temperature around the head of the dynamic pressure sensor inside the probe to below 500K.

[0024] Beneficial effect 2: The probe has high integration. This water-cooled pressure probe can be customized according to different combustion chamber structures and measurement requirements, such as changing parameters like the length, diameter, and cooling flow rate of the probe to adapt to various complex measurement environments and working conditions. In addition, it can be integrated with other measurement devices (such as temperature sensors, flow sensors, etc.) to achieve comprehensive measurement of multiple parameters.

[0025] Beneficial effect 3: The manufacturing cost of the probe is relatively low. Compared with some new high-temperature pressure measurement technologies (such as fiber optic pressure sensors), the water-cooled pressure probe has a relatively low cost and a high technology maturity, with good cost performance. This enables it to be widely used in the field of high-temperature pressure measurement in aeroengine combustion chambers, especially in some occasions where strict cost control is required.

[0026] Beneficial effect 4: The measurement accuracy of the probe is very high. Since the cooling system can control the temperature inside the probe within a relatively stable range, the pressure sensor can operate within the optimal working temperature range, thus ensuring high measurement accuracy and high repeatability. Its measurement accuracy can reach ±0.1% - ±0.5%, which can meet the strict requirements of aeroengine combustion chamber pressure measurement.

[0027] Beneficial effect 5: The probe can avoid local ablation. Cooling water flows into the probe housing through four water inlet channels, which can ensure the smooth flow of cooling water, prevent the occurrence of cavities inside the probe resulting in insufficient heat transfer, and at the same time reduce the occurrence of backflow and minimize flow losses.

[0028] Beneficial effect 6: The measurement range of the probe is very wide. Twelve pressure sensing holes are divided into top layer, middle layer, and bottom layer, and are alternately distributed on the side of the probe head. This probe broadens the measurement range in the direction of the probe head central axis.

[0029] Beneficial effect 7: Two-dimensional flow field parameters can be measured without using a displacement mechanism. Any three adjacent pressure sensing holes can be approximately regarded as a three-hole pressure probe. Since this probe has twelve pressure sensing holes, two-dimensional flow field parameters can be obtained from the measurement data of multiple pressure sensing holes without using a displacement mechanism to rotate the probe.

[0030] Beneficial effect eight: The probe has good structural strength. Due to the harsh test environment in the combustion chamber, the probe is in a high-temperature and high-pressure environment. The high-pressure cooling water can balance the pressure difference inside and outside the probe housing. The inlet channels and outlet channels are arranged alternately, providing strong support for the probe housing. At the same time, since the overall cooling effect of the probe is relatively uniform and it is subjected to less thermal stress, it has higher structural strength. Description of the Drawings

[0031] Figure 1 It is a schematic diagram of the overall structure of a double-helix twelve-hole water-cooled dynamic pressure probe for measuring three-dimensional parameters of the combustion chamber recirculation flow field in an embodiment of the present invention.

[0032] Figure 2 is Figure 1 the right view of

[0033] Figure 3 is Figure 2 the bottom view of

[0034] Figure 4 is Figure 2 the sectional view taken along the B-B section of

[0035] Figure 5 is Figure 2 the sectional view taken along the C-C section of

[0036] Figure 6 is Figure 1 the left view of

[0037] Figure 7 is Figure 1 the sectional view taken along the A-A section of

[0038] Figure 8 is Figure 6 the sectional view taken along the D-D section of

[0039] Figure 9 is Figure 6 the sectional view taken along the E-E section of

[0040] Wherein: 1 - probe head, 2 - probe strut, 3, 4, 5, 6 - four pressure sensing holes in the top layer of the probe head, 7, 8, 9, 10 - four pressure sensing holes in the middle layer of the probe head, 11, 12, 13, 14 - four pressure sensing holes in the bottom layer of the probe head, 15 - wire cavity, 16 - partition plate, 17, 18, 19, 20 - inlet channels, 21, 22, 23, 24 - outlet channels. Specific Embodiments

[0041] The present invention will be described in detail below in conjunction with the accompanying drawings and a specific embodiment, 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.

[0042] As Figure 1 , Figure 2 and Figure 6 shown, in this embodiment, a double - helix twelve - hole water - cooled dynamic pressure probe for measuring three - dimensional parameters of the recirculation flow field in a combustion chamber is introduced. The probe is composed of a probe head (1), a probe strut (2), pressure - sensing holes (3), (4), (5), (6) on the top layer of the probe head, pressure - sensing holes (7), (8), (9), (10) in the middle layer of the probe head, pressure - sensing holes (11), (12), (13), (14) on the bottom layer of the probe head, a wire - routing cavity (15), a partition plate (16), four water - inlet channels (17), (18), (19), (20) and four water - outlet channels (21), (22), (23), (24). The probe head (1) has a cylindrical shape, with a diameter of 20 mm and a length of 50 mm. The diameter of the pressure - sensing holes is 1 mm. The diameter of the probe strut (2) is 26 mm and the length is 500 mm. The shells of the probe head (1) and the probe strut (2) are both made of Inconel alloy material, and their surfaces are both coated with high - temperature heat - insulating coatings. The pressure - measuring holes are divided into top, middle and bottom layers, and are arranged circumferentially in a staggered manner on the side of the probe head (1). Their aperture is 1 mm. The distance from the center lines of the four pressure - sensing holes (3), (4), (5), (6) on the top layer of the probe head to the upper surface of the probe head (1) is 6 mm. The plane where the central axes of the four pressure - sensing holes (7), (8), (9), (10) in the middle layer of the probe head are located is 3 mm away from the plane where the central axes of the four pressure - sensing holes (2), (3), (4), (5), (6) on the top layer of the probe head are located. And the angle between the plane where the central axis of the middle - layer pressure - sensing holes and the central axis of the probe head and the plane where the central axis of the top - layer pressure - sensing holes and the central axis of the probe head is 45°. The four pressure - sensing holes (11), (12), (13), (14) on the bottom layer of the probe head are respectively located directly below the four pressure - sensing holes (3), (4), (5), (6) on the top layer of the probe head, and the distance between the plane where the central axes of the four pressure - sensing holes on the top layer are located and the plane where the central axes of the four pressure - sensing holes on the bottom layer are located is 6 mm.

[0043] Figure 3 For Figure 2An upward view. In this embodiment, the inlets of the four water inlet channels (17), (18), (19), and (20) of the probe and the outlets of the four water outlet channels (21), (22), (23), and (24) are located at the bottom of the probe rod (2). The inlets of the four water inlet channels (17), (18), (19), and (20) are provided with internal threads, with a diameter of 2 mm, and the length of the straight line segment of the central axis of each water inlet channel inlet is 10 mm. The length of the straight line segment of the central axis of the outlets of the four water outlet channels (21), (22), (23), and (24) is 12 mm, and external threads are provided.

[0044] Figure 4 is Figure 2 The B-B view of. The distance between the upper top surface of the wire routing cavity (15) and the probe head (1) is 5 mm, and the diameter is 4 mm.

[0045] Figure 5 is Figure 2 The C-C view of. The cooling water in the four water inlet channels (17), (18), (19), and (20) flows into the four water outlet channels (21), (22), (23), and (24) under the action of the partition plate (16), centrifugal force, and pressure difference.

[0046] Figure 7 , Figure 8 and Figure 9 are respectively Figure 1 The A-A view of, Figure 6 The D-D view of and Figure 6 The E-E view of. The dynamic pressure sensor is installed at the twelve pressure sensing holes (2), (3), (4), (5), (6), (7), (8), (9), (10), (11), (12), (13), (14) at the connection with the wire routing cavity (15). The cable is led out through the outlet of the wire routing cavity (15) at the tail of the probe rod (2) and then connected to a micro pressure transmitter and a data acquisition module. The pressure sensor is sealed with a high-temperature resistant liquid glue to ensure the accuracy of measurement. The measurement accuracy of the pressure sensor is 0.1%, and the natural frequency is 300 kHz.

[0047] A double-helix twelve-hole water-cooled dynamic pressure probe for measuring three-dimensional parameters of the recirculation flow field in a combustion chamber, introduced in the embodiments of the present invention, can obtain calibration data through calibration in a calibration wind tunnel. When actually measuring the two-dimensional flow field of an aero-engine combustion chamber, the central axis of the head (1) of the twelve-hole water-cooled dynamic pressure probe is perpendicular to the oncoming flow direction. Several sets of unsteady pressure data are measured by the dynamic pressure sensors inside the probe. By combining the data measured by the twelve pressure sensing holes, the results of multiple three-hole dynamic pressure probes are obtained. Then, using the calibration data obtained from the calibration wind tunnel for data processing, the flow parameters such as the deflection angle, total pressure, static pressure, and Mach number of the two-dimensional flow field of the aero-engine combustion chamber can be obtained without rotating the probe. After cooling water is introduced, dynamic measurement of the flow field parameters can be realized in a high-temperature environment of 2500K, and the frequency response of the probe exceeds 25kHz.

Claims

1. A double - helix twelve - hole water - cooled dynamic pressure probe for measuring two - dimensional parameters of the recirculation flow field in a combustion chamber with a wide range, mainly composed of a probe head (1), a probe strut (2), pressure - sensing holes (3), (4), (5), (6) on the top layer of the probe head, pressure - sensing holes (7), (8), (9), (10) in the middle layer of the probe head, pressure - sensing holes (11), (12), (13), (14) on the bottom layer of the probe head, a wire - routing cavity (15), a partition plate (16), four water - inlet channels (17), (18), (19), (20) and four water - outlet channels (21), (22), (23), (24), and is characterized in that: The probe head (1) is cylindrical in shape, with a diameter of 10 mm to 30 mm and a length of 20 mm to 80 mm. Both the probe head (1) and the housing of the probe rod (2) are made of Inconel alloy material, and their surfaces are coated with high-temperature heat-insulating coatings. The pressure measurement holes are divided into top layer, middle layer and bottom layer, which are arranged circumferentially in a staggered manner on the side of the probe head (1). The aperture of the pressure measurement holes is 0.5 mm to 2 mm. The distance from the center lines of the four pressure sensing holes on the top layer of the probe head (3), (4), (5), (6) to the upper top surface of the probe head (1) is 3 mm to 10 mm. The plane where the central axes of the four pressure sensing holes in the middle layer of the probe head (7), (8), (9), (10) are located is 1 mm to 5 mm away from the plane where the central axes of the four pressure sensing holes on the top layer of the probe head (2), (3), (4), (5), (6) are located. And the angle between the plane where the central axis of the pressure sensing hole in the middle layer and the central axis of the probe head and the plane where the central axis of the pressure sensing hole in the top layer and the central axis of the probe head is 45°. The four pressure sensing holes on the bottom layer of the probe head (11), (12), (13), (14) are respectively located directly below the four pressure sensing holes on the top layer of the probe head (3), (4), (5), (6). And the distance between the plane where the central axes of the four pressure sensing holes on the top layer are located and the plane where the central axes of the four pressure sensing holes on the bottom layer are located is 6 mm to 20 mm. The pressure sensors are fixed to the connections between each pressure sensing hole and the wire routing cavity (15) using high-temperature-resistant silicone. The wires are led out through the outlet of the wire routing cavity (15) at the tail of the probe rod (2), connected to a micro pressure transmitter and then to the test module. The diameter of the wire routing cavity (15) is 2 mm to 5 mm. The measurement accuracy of the pressure sensors is 0.1% to 0.5%, and the natural frequency is 100 Hz to 300 KHz. The water inlet system inside the probe consists of four water inlet channels (17), (18), (19), (20). Each water inlet channel is located in the inner layer helix and converges at the top of the probe head (1) with four water outlet channels (21), (22), (23), (24). The diameter of each water inlet channel is 0.5 mm to 5 mm. At the inlet of each of the four water inlet channels (17), (18), (19), (20), there is a straight pipe with internal threads. The central axes of the four straight pipes are smoothly transitioned with the helical lines of the corresponding water inlet channels to reduce flow losses. The length of the straight pipe is 1 mm to 8 mm. The water outlet system inside the probe consists of four water outlet channels (21), (22), (23), (24). Each water outlet channel is located in the outer layer helix. At the outlet of each of the four water outlet channels (21), (22), (23), (24), there is a straight pipe with external threads. The central axes of the four straight pipes are smoothly transitioned with the helical lines of the corresponding water outlet channels to reduce flow losses. The length of the straight pipe is 1 mm to 10 mm. The centerlines of the four water inlet channels (17), (18), (19), and (20) and the water outlet channels (21), (22), (23), and (24) inside the probe all adopt a variable pitch design to ensure smoother flow of the cooling water, with the pitch ranging from 2 mm to 20 mm; The present invention relates to a double - helix twelve - hole water - cooled dynamic pressure probe for measuring two - dimensional parameters of the recirculation flow field in a combustion chamber over a wide range. After calibration in a calibration wind tunnel, calibration data can be obtained. When actually measuring the two - dimensional flow field of an aero - engine combustion chamber, the central axis of the head (1) of the twelve - hole water - cooled dynamic pressure probe is perpendicular to the oncoming flow direction. Several sets of unsteady pressure data are measured by the dynamic pressure sensors inside the probe. By combining the data measured through the twelve pressure - sensing holes and then using the calibration data obtained from the calibration wind tunnel for data processing, the flow parameters such as the deflection angle, total pressure, static pressure, and Mach number of the two - dimensional flow field of the aero - engine combustion chamber can be obtained without rotating the probe. After cooling water is introduced, dynamic measurement of the flow field parameters can be achieved in a high - temperature environment of 2500K, and the frequency response of this probe exceeds 25 kHz.

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