Water-cooled wall surface static pressure probe with multiple cooling loops for measuring high-temperature flow field of combustion chamber

Abstract

The utility model belongs to the technical field of high-temperature flow field pressure testing, and discloses a water-cooled wall surface static pressure probe provided with multiple cooling loops and used for measuring a high-temperature flow field of an aero-engine combustion chamber. The device is characterized by comprising a pressure sensing hole, a fixed external thread, an octagonal prism positioning block, a fixed internal thread, a sensor mounting cavity, eight water outlet channels and eight water inlet channels. Compared with an existing water-cooling pressure probe, the probe can measure the wall surface static pressure of a flow field under the condition that the interference on the flow field is as small as possible, and meanwhile, the water-cooling pressure probe can adjust the cooling effect of each area of the probe. When the wall surface static pressure of a high-temperature flow field of a combustion chamber of an aero-engine is actually measured, the water-cooled wall surface static pressure probe is fixed in a static pressure hole which is formed in the wall surface of the combustion chamber in advance, a pressure sensor is mounted in the probe, and the water-cooled wall surface static pressure probe can measure the wall surface static pressure in the combustion chamber in a 2500K high-temperature environment through the calibration of a shock tube. And the frequency response of the probe exceeds 80 kHz.

Description

Technical Field

[0001] This invention belongs to the field of high-temperature pressure testing technology and relates to a high-temperature flow field wall static pressure measuring device. Specifically, it relates to a water-cooled wall static pressure probe with multiple cooling circuits for measuring the high-temperature flow field of the combustion chamber of an aero-engine, which is suitable for measuring the static pressure of the inner wall of the combustion chamber of an aero-engine. Background Technology

[0002] The combustion chamber of an aero-engine is one of its core components, and its internal high-temperature, high-pressure environment plays a decisive role in the engine's performance, efficiency, and safety. The pressure distribution and dynamic changes within the combustion chamber directly affect fuel combustion efficiency, thrust output, thermal efficiency, and stable engine operation. High-temperature static pressure measurement technology for combustion chambers is an important branch of aero-engine testing, aiming to accurately measure the static pressure distribution of gases within the combustion chamber, providing crucial data support for engine design optimization, performance evaluation, and fault diagnosis. The static pressure distribution within the combustion chamber directly affects the fuel-air mixing effect and combustion efficiency. By accurately measuring static pressure, the combustion process can be optimized, improving engine fuel economy and thrust output. Static pressure data is the foundation of combustion chamber thermodynamic analysis, helping to understand the energy conversion and transfer mechanisms during combustion and providing a basis for evaluating the engine's thermodynamic performance. High-temperature static pressure measurement can monitor the pressure distribution on the inner walls of the combustion chamber, providing pressure load data for combustion chamber structural design and ensuring the structural safety and reliability of the combustion chamber under high-temperature and high-pressure environments. Abnormal static pressure distribution can be an early sign of combustion chamber malfunctions, such as incomplete combustion, nozzle blockage, or cracks. Real-time monitoring of static pressure can help detect potential faults and provide early warnings, ensuring the safe operation of the engine.

[0003] However, the temperature inside the combustion chamber typically exceeds 1500℃, placing extremely high demands on the high-temperature resistance of the measuring equipment. The measuring probe needs to maintain stability and accuracy under high-temperature conditions while avoiding measurement errors caused by factors such as thermal expansion. The pressure inside the combustion chamber can reach tens of atmospheres, requiring the measuring equipment to possess high-precision and high-reliability pressure measurement capabilities, while also being able to withstand the mechanical stress under high pressure. Simultaneously, the combustion chamber contains complex turbulence and swirling flows; static pressure measurement requires accurately capturing the pressure distribution in a dynamic flow field, posing challenges to the measurement probe's response speed and spatial resolution. Furthermore, the complex chemical reactions and combustion products within the combustion chamber can interfere with pressure measurement, increasing the difficulty and error. In addition, the high-temperature environment inside the combustion chamber can lead to the generation of corrosive gases such as sulfur dioxide and sulfur trioxide, which can corrode the surface and internal structure of the measuring equipment, affecting measurement accuracy and equipment lifespan. Therefore, high-temperature static pressure measuring equipment needs to be made of high-temperature and corrosion-resistant materials, and its structural strength and measurement accuracy must be ensured through precision machining.

[0004] Commonly used pressure measurement methods, such as PSP pressure-sensitive coating testing technology, have high requirements for optical path arrangement, and their test objects are often the surface pressure of the test object, making it difficult to meet the requirements for flow field testing in the combustion chamber. Fiber optic pressure sensors, based on fiber optic sensing technology, have advantages such as high temperature resistance, electromagnetic interference resistance, and small size, but currently still face problems such as high cost and limited measurement range. Conventional pressure probe materials cannot withstand temperatures exceeding 1300K, and dynamic pressure sensor heads cannot withstand temperatures exceeding 500K, which can damage the probe during measurement and prevent the measurement from being performed. Water-cooled pressure probes utilize the cooling properties of water to transform 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 measurement equipment. After decades of development, water-cooled pressure probe technology has been continuously improved, with significant progress in its structural design, cooling efficiency, measurement accuracy, and reliability, becoming one of the important tools for high-temperature pressure measurement in aero-engine combustion chambers. Unlike conventional water-cooled pressure probes, water-cooled wall static pressure probes are located in the wall static pressure holes opened in the aero-engine combustion chamber wall, with minimal interference to the flow field. The water-cooled pressure probe has multiple cooling channels inside, through which cooling water circulates. The probe head is directly exposed to a high-temperature environment, and the absorbed heat is transferred to the cooling water in the cooling channels via heat conduction. The cooling water then carries away the heat, thereby reducing the temperature of the probe head.

[0005] The basic structure of a water-cooled wall-mounted static pressure probe consists of three parts: a probe housing, a cooling channel, and a pressure sensor. The probe head is directly exposed to the high-temperature environment of the combustion chamber to acquire pressure signals. The cooling system uses circulating water to remove heat from the probe head, lowering the internal temperature of the probe to the range where the pressure sensor can operate normally. The internal static pressure measuring element (such as the pressure sensor) is installed within the protected area of ​​the cooling channel. The cooling water keeps its operating temperature within the allowable range, ensuring the accuracy and stability of the measuring element. The working principle of the water-cooled pressure probe can be summarized as follows: utilizing the high specific heat capacity and good thermal conductivity of water, heat from the high-temperature environment is rapidly transferred to the outside, thereby protecting the internal pressure sensor from high-temperature damage and ensuring the accuracy and stability of the measurement signal.

[0006] Existing water-cooled pressure probes (such as the concave spherical probe for measuring three-dimensional steady-state high-temperature flow fields, patent number 2024109924831) utilize built-in cooling pipes for impact cooling in high-temperature regions to significantly enhance the high-temperature resistance of the water-cooled pressure probe. However, this probe can only measure steady-state high-temperature flow fields and cannot perform real-time measurements of unsteady fields. Dynamic pressure probes are difficult to miniaturize; large sizes severely interfere with the measured flow field. Furthermore, dynamic pressure probes are too expensive. Existing probes with water-cooling structures (such as the invention patent: a water-cooled pressure probe for measuring three-dimensional dynamic high-temperature flow fields between turbine stages, patent number 2024109924174) employ a wedge-shaped structure and optimize the probe's water inlet method. They also place the dynamic pressure sensor inside the pressure measurement hole, enabling the measurement of three-dimensional dynamic parameters of the flow field. However, this probe, due to its insertion into the flow field, struggles to withstand the 2500K high temperature inside the combustion chamber, thus failing to measure the static pressure within the combustion chamber. Existing water-cooled pressure probes for measuring the internal flow field of the combustion chamber (invention patent: an omnidirectional four-hole water-cooled dynamic pressure probe for measuring the backflow field of the combustion chamber, 2024109925656) measure two-dimensional flow parameters of the backflow field in the combustion chamber. The manufacturing process is complex and the spatial resolution is low, making it impossible to measure the wall static pressure at multiple points in the combustion chamber.

[0007] Existing water-cooled pressure probes are insufficient to meet the testing requirements for measuring the static pressure of the combustion chamber walls under high-temperature conditions, especially at extreme temperatures of 2500K. Existing probes either fail to meet the testing needs in high-temperature environments or have complex manufacturing processes that result in excessively high costs and are inconvenient to produce. Therefore, there is an urgent need for a water-cooled fast-response static pressure probe suitable for high temperatures, capable of preventing localized ablation, and with relatively low manufacturing costs, capable of achieving the static pressure measurement of aero-engine combustion chamber walls. Summary of the Invention

[0008] The technical problem to be solved by this invention is: since existing pressure probes cannot meet the test requirements for measuring the static pressure of the combustion chamber wall of an aero-engine, especially the static pressure test requirements at an extreme high temperature of 2500K, a water-cooled dynamic pressure probe for the combustion chamber wall that is resistant to high temperature and can realize the measurement of static pressure of the combustion chamber wall is invented.

[0009] To address this, the present invention provides a water-cooled wall static pressure probe with multiple cooling circuits for measuring the high-temperature flow field in an aero-engine combustion chamber. During measurement, cooling water is introduced into the probe's inlet, flows through the probe's interior, and exits through the outlet. Compared to existing probes, the water-cooled wall static pressure probe allows for the measurement of wall static pressure in the high-temperature flow field within an aero-engine combustion chamber with minimal interference to the flow field. Furthermore, the inclusion of a special cooling structure within the probe actively adjusts the cooling effect of each part, avoiding thermal stress concentration caused by excessive temperature differences and significantly improving the probe's adaptability to harsh environments. In actual measurement of the wall static pressure in the high-temperature flow field of an aero-engine combustion chamber, the water-cooled wall static pressure probe is fixed within a pre-drilled static pressure hole on the combustion chamber wall. A pressure sensor is installed inside the probe. After calibration with a shock tube, the water-cooled wall static pressure probe can measure wall static pressure at a high temperature of 2500K within the combustion chamber, and its frequency response exceeds 80kHz.

[0010] The solution of this invention is:

[0011] 1. A water-cooled wall static pressure probe with multiple cooling circuits for measuring the high-temperature flow field of a combustion chamber, comprising: a pressure sensing hole (1), a fixed external thread (2), an octagonal prism positioning block (3), a fixed internal thread (4), a sensor mounting cavity (5), water outlet channels 1 (6), 2 (8), 3 (10), 4 (12), 5 (14), 6 (16), 7 (18), and 8 (20), and water inlet channels 1 (7), 2 (9), 3 (11), 4 (13), 5 (15), 6 (17), and 7 (19). The No. 8 water inlet channel (21) is characterized in that: the probe is approximately cylindrical in shape, with a diameter of 6 mm to 14 mm and a length of 10 mm to 50 mm. The probe housing is made of Inconel high-temperature resistant alloy material and the surface is coated with heat-insulating paint. A pressure sensing hole (1) is opened at the top of the probe to sense the static pressure of the flow field. The diameter of the pressure sensing hole (1) is 0.2 mm to 2 mm and the depth is 1 mm to 5 mm. A fixing external thread (2) is opened on the side of the probe near the pressure sensing hole (1) to fix the water-cooled wall static pressure probe in the static pressure hole opened on the combustion chamber wall. An octagonal prism positioning block (3) is milled at the bottom of the probe to install and position the water-cooled wall static pressure probe.

[0012] 2. Further, a sensor mounting cavity (5) is opened inside the probe. A fixing internal thread (4) is opened on the side of the sensor mounting cavity (5) near the pressure sensing hole (1) to fix the pressure sensor. The pressure sensor has a measurement accuracy of 0.1%~0.5% and a natural frequency of 300Hz~500kHz. The diameter of the sensor mounting cavity (5) is 1 mm~2 mm. The cable is led out from the sensor mounting cavity (5) near the bottom end of the probe.

[0013] 3. Further, the pressure probe has outlet channels 1 (6), 2 (8), 3 (10), 4 (12), 5 (14), 6 (16), 7 (18), and 8 (20) at its bottom, and inlet channels 1 (7), 2 (9), 3 (11), 4 (13), 5 (15), 6 (17), 7 (19), and 8 (21). The inlet channels are evenly distributed circumferentially inside the probe near the sensor mounting cavity (5), and the outlet channels are evenly distributed circumferentially inside the probe away from the sensor mounting cavity (5). Water channel (6) is connected to water inlet channel (7) No. 1, water outlet channel (8) No. 2 and water inlet channel (9), water outlet channel (10) No. 3 and water inlet channel (11), water outlet channel (12) No. 4 and water inlet channel (13), water outlet channel (14) No. 5 and water inlet channel (15), water outlet channel (16) No. 6 and water inlet channel (17), water outlet channel (18) No. 7 and water inlet channel (19), water outlet channel (20) No. 8 and water inlet channel (21) at the top of the probe respectively. The diameter of the water inlet and water outlet channels is 0.5 mm to 3 mm. The distance between the center line of any water inlet channel and the center line of the probe is 1.5 mm to 5 mm. The distance between the center line of any water outlet channel and the center line of the probe is 2 mm to 8 mm.

[0014] This invention discloses a water-cooled wall static pressure probe with multiple cooling circuits for measuring the high-temperature flow field of a combustion chamber. During measurement, cooling water is introduced into the probe's inlet, flows through the probe's interior, and exits through the outlet. In actual measurement of the wall static pressure of the high-temperature flow field in an aero-engine combustion chamber, this water-cooled wall static pressure probe is fixed within a pre-drilled static pressure hole on the combustion chamber wall. A pressure sensor is installed inside the probe. After calibration with a shock tube, this water-cooled wall static pressure probe can measure the wall static pressure at a high temperature of 2500K within the combustion chamber, and its frequency response exceeds 80kHz.

[0015] This invention, a water-cooled wall static pressure probe with multiple cooling circuits for measuring the high-temperature flow field in a combustion chamber, has the following beneficial effects:

[0016] Benefit 1: This probe enables measurements in high-temperature environments. After shock tube calibration, this invention can be used to measure the static pressure on the combustion chamber walls of aero-engines, providing experimental data for improving the performance of aero-engine combustion chambers. Compared with conventional measurement probes, this probe enables measurements in high-temperature environments. After injecting cooling water, the cooling effect around the sensing part of the probe is improved, causing the temperature around the dynamic pressure sensor head inside the probe to drop below 500K.

[0017] Benefit Two: The probe has a simple manufacturing process and low manufacturing cost. 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 high technological maturity, offering good cost-effectiveness. This has led to its widespread application in the field of high-temperature pressure measurement in aero-engine combustion chambers, especially in situations where cost control is stringent.

[0018] Benefit 3: Less interference with the flow field. Compared with conventional water-cooled pressure probes that extend into the flow field for measurement, creating static pressure holes in the wall and then installing the water-cooled wall static pressure probe on the wall can reduce the interference to the flow field caused by the probe measurement.

[0019] Benefit 4: The internal cooling structure of this probe can enhance the convective heat transfer between the cooling water and the high-temperature side. The cooling channels are connected at the probe head. After the cooling water enters the probe's water inlet channel, it impacts and cools the high-temperature airflow side wall at the top of the probe. This cooling method can enhance the heat transfer between the cooling water and the high-temperature fluid side of the probe shell.

[0020] Benefit 5: The cooling effect of each area of ​​the probe can be adjusted. The probe has eight water inlet channels and eight water outlet channels, but the water inlet channels are not connected to each other, nor are the water outlet channels connected to each other. Therefore, the cooling effect of each area of ​​the probe can be adjusted by adjusting the cooling water flow rate, temperature, pressure and other parameters of each water inlet channel according to the different heating of the probe in the circumference.

[0021] Benefit 6: Prevents localized ablation of the probe. The probe has numerous cooling channels, and none of these channels contain separation areas with significant flow losses, thus preventing localized ablation caused by cooling water entering cavities within the probe. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of a water-cooled wall static pressure probe with multiple cooling circuits for measuring the high-temperature flow field of a combustion chamber, according to an embodiment of the present invention.

[0023] Figure 2 yes Figure 1 The front view.

[0024] Figure 3 yes Figure 2 Sectional view of section AA.

[0025] Figure 4 yes Figure 2 BB section sectional view.

[0026] Figure 5 yes Figure 2 The CC section sectional view.

[0027] Figure 6 yes Figure 2 DD section sectional view.

[0028] Among them: 1-pressure sensing hole, 2-fixed external thread, 3-octagonal prism positioning block, 4-fixed internal thread, 5-sensor mounting cavity, 6-1 water outlet channel, 8-2 water outlet channel, 10-3 water outlet channel, 12-4 water outlet channel, 14-5 water outlet channel, 16-6 water outlet channel, 18-7 water outlet channel, 20-8 water outlet channel, 7-1 water inlet channel, 9-2 water inlet channel, 11-3 water inlet channel, 13-4 water inlet channel, 15-5 water inlet channel, 17-6 water inlet channel, 19-7 water inlet channel, 21-8 water inlet channel. Detailed Implementation

[0029] The present invention will now be described in detail with reference to 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 explicit definition of the scope of protection of the present invention.

[0030] like Figure 1 and Figure 2 As shown, this embodiment introduces a water-cooled wall static pressure probe with multiple cooling circuits for measuring the high-temperature flow field of a combustion chamber. It consists of a pressure sensing hole (1), a fixed external thread (2), an octagonal prism positioning block (3), a fixed internal thread (4), a sensor mounting cavity (5), water outlet channels 1 (6), 2 (8), 3 (10), 4 (12), 5 (14), 6 (16), 7 (18), and 8 (20), and water inlet channels 1 (7), 2 (9), 3 (11), 4 (13), 5 (15), and 6 (17). The probe consists of a No. 7 water inlet channel (19) and a No. 8 water inlet channel (21). The probe is approximately cylindrical in shape, with a diameter of 5 mm and a length of 12 mm. The probe housing is made of Inconel high-temperature resistant alloy material and coated with heat-insulating paint. A pressure sensing hole (1) is opened at the top of the probe to sense the static pressure of the flow field. The pressure sensing hole (1) has a diameter of 0.5 mm and a depth of 0.5 mm. A fixing external thread (2) is opened on the side of the probe near the pressure sensing hole (1) to fix the water-cooled wall static pressure probe in the static pressure hole opened on the combustion chamber wall. An octagonal prism positioning block (3) is milled at the bottom of the probe to install and position the water-cooled wall static pressure probe.

[0031] like Figure 3As shown, a sensor mounting cavity (5) is opened inside the probe. A fixing internal thread (4) is opened on the side of the sensor mounting cavity (5) near the pressure sensing hole (1) to fix the pressure sensor. The diameter of the sensor mounting cavity (5) is 1 mm. The cable is led out from the sensor mounting cavity (5) near the bottom end of the probe.

[0032] like Figure 4 , Figure 5 , Figure 6 As shown, the pressure probe has outlet channels 1 (6), 2 (8), 3 (10), 4 (12), 5 (14), 6 (16), 7 (18), and 8 (20) at its bottom, and inlet channels 1 (7), 2 (9), 3 (11), 4 (13), 5 (15), 6 (17), 7 (19), and 8 (21). The inlet channels are evenly distributed circumferentially inside the probe near the sensor mounting cavity (5), and the outlet channels are evenly distributed circumferentially inside the probe away from the sensor mounting cavity (5). The No. 1 water outlet channel (6) is connected to the No. 1 water inlet channel (7), the No. 2 water outlet channel (8) is connected to the No. 2 water inlet channel (9), the No. 3 water outlet channel (10) is connected to the No. 3 water inlet channel (11), the No. 4 water outlet channel (12) is connected to the No. 4 water inlet channel (13), the No. 5 water outlet channel (14) is connected to the No. 5 water inlet channel (15), the No. 6 water outlet channel (16) is connected to the No. 6 water inlet channel (17), the No. 7 water outlet channel (18) is connected to the No. 7 water inlet channel (19), and the No. 8 water outlet channel (20) is connected to the No. 8 water inlet channel (21) at the top of the probe. The diameter of the water inlet and water outlet channels is 0.5 mm. The distance between the center line of any water inlet channel and the center line of the probe is 1.5 mm, and the distance between the center line of any water outlet channel and the center line of the probe is 2.2 mm.

[0033] This invention presents a water-cooled wall static pressure probe with multiple cooling circuits for measuring the high-temperature flow field of a combustion chamber. During measurement, cooling water is introduced into the probe's inlet, flows through the probe's interior, and exits through the drain outlet. In actual measurement of the wall static pressure of the high-temperature flow field in an aero-engine combustion chamber, this water-cooled wall static pressure probe is fixed within a pre-drilled static pressure hole on the combustion chamber wall. A pressure sensor is installed inside the probe. After calibration with a shock tube, this water-cooled wall static pressure probe can measure the wall static pressure at a high temperature of 2500K within the combustion chamber, and its frequency response exceeds 80kHz.

Claims

1. A water-cooled wall static pressure probe with multiple cooling circuits for measuring the high-temperature flow field in a combustion chamber, characterized in that: The probe is approximately cylindrical in shape, with a diameter of 6 mm to 14 mm and a length of 10 mm to 50 mm. The probe housing is made of Inconel high-temperature resistant alloy material and the surface is coated with heat-insulating paint. A pressure sensing hole (1) is opened at the top of the probe to sense the static pressure of the flow field. The diameter of the pressure sensing hole (1) is 0.2 mm to 2 mm and the depth is 1 mm to 5 mm. A fixing external thread (2) is opened on the side of the probe near the pressure sensing hole (1) to fix the water-cooled wall static pressure probe in the static pressure hole opened on the combustion chamber wall. An octagonal prism positioning block (3) is milled at the bottom of the probe to install and position the water-cooled wall static pressure probe. Furthermore, a sensor mounting cavity (5) is opened inside the probe. A fixing internal thread (4) is opened on the side of the sensor mounting cavity (5) near the pressure sensing hole (1) to fix the pressure sensor. The pressure sensor has a measurement accuracy of 0.1%~0.5% and a natural frequency of 300Hz~500kHz. The diameter of the sensor mounting cavity (5) is 1 mm~2 mm. The cable is led out from the sensor mounting cavity (5) near the bottom end of the probe. Furthermore, the water-cooled wall static pressure probe for measuring the high-temperature flow field of the combustion chamber with multiple cooling circuits has water outlet channels 1 (6), 2 (8), 3 (10), 4 (12), 5 (14), 6 (16), 7 (18), and 8 (20) and water inlet channels 1 (7), 2 (9), 3 (11), 4 (13), 5 (15), 6 (17), 7 (19), and 8 (21) at the bottom. The water inlet channels are evenly distributed circumferentially inside the probe near the sensor mounting cavity (5), and the water outlet channels are evenly distributed circumferentially inside the probe away from the sensor. At the installation cavity (5), water outlet channel 1 (6) is connected to water inlet channel 1 (7), water outlet channel 2 (8) is connected to water inlet channel 2 (9), water outlet channel 3 (10) is connected to water inlet channel 3 (11), water outlet channel 4 (12) is connected to water inlet channel 4 (13), water outlet channel 5 (14) is connected to water inlet channel 5 (15), water outlet channel 6 (16) is connected to water inlet channel 6 (17), water outlet channel 7 (18) is connected to water inlet channel 7 (19), and water outlet channel 8 (20) is connected to water inlet channel 8 (21) at the top of the probe. The diameter of the water inlet and outlet channels is 0.5 mm to 3 mm. The distance between the center line of any water inlet channel and the center line of the probe is 1.5 mm to 5 mm, and the distance between the center line of any water outlet channel and the center line of the probe is 2 mm to 8 mm.

Images