A flow field measurement method for aeroengine crosswind test

Abstract

The present application belongs to the field of aircraft engine crosswind test, and particularly relates to a flow field measurement method for aircraft engine crosswind test. It includes: step one, determining the environmental conditions for flow field measurement; step two, determining the flow field measurement requirements; step three, obtaining measurement equipment, and determining the flow field measurement points; step four, conducting a crosswind test based on the environmental conditions, the flow field measurement requirements, the measurement equipment, and the flow field measurement points, and recording the flow field measurement data; step five, realizing flow field measurement data processing. The flow field measurement method for aircraft engine crosswind test of the present application can measure the real flow field characteristics of the crosswind environment generated by the crosswind device; can obtain the boundary of the crosswind environment generated by the crosswind device and the range of the core wind speed zone; for two actual working conditions with or without the engine on the test bench, the flow field conditions around the engine are measured.

Description

Technical Field

[0001] The present application relates to the field of aero-engine crosswind testing, and in particular to a flow field measurement method for aero-engine crosswind testing. Background Art

[0002] The aerodynamic stability and performance of aircraft engines are affected by the quality of the airflow entering the engine. Crosswinds are a common condition encountered by aircraft engines during takeoff and landing, and they can have an impact on their stability and performance. In a strong crosswind environment, the air flow field at the engine inlet is uneven, and the intake distortion index increases, affecting the engine's operating stability. Crosswinds with greater energy can even cause the engine to malfunction. Therefore, there is a need for aircraft engines to conduct whole-machine crosswind environment simulation tests. Crosswind tests are used to assess the impact of crosswinds on the engine's stability margin and evaluate the engine's stable operating margin. As an important test for assessing an aircraft engine's ability to adapt to special intake environments, the crosswind conditions that can be simulated by the test bench are crucial. Therefore, before conducting crosswind tests on aircraft engines, crosswind flow field tests should be conducted to evaluate the quality of the crosswind flow field.

[0003] my country's research and development of crosswind tests are still in their infancy. There is a lack of experience and standards in this area. There are only methods for calibrating wind speeds for crosswind tests. Existing methods for calibrating wind speeds have the following shortcomings:

[0004] ① The crosswind speed calibration method obtains a single wind speed index and only measures the wind speed on the characteristic test section. It cannot reflect the flow field conditions in the global range from the crosswind device outlet to the engine end, and cannot make an objective evaluation of the crosswind flow field quality and crosswind field boundary.

[0005] ②The crosswind speed calibration method cannot measure total pressure and static pressure.

[0006] ③The crosswind speed calibration method requires the use of a test bench. The test bench cannot be used to install the engine during measurement, and it is impossible to measure the actual wind speed around the engine under crosswind conditions.

[0007] Therefore, it is desired to have a technical solution to overcome or at least alleviate at least one of the above-mentioned deficiencies of the prior art. Summary of the Invention

[0008] The purpose of this application is to provide a flow field measurement method for a crosswind test of an aircraft engine to solve at least one problem existing in the prior art.

[0009] The technical solution of this application is:

[0010] A flow field measurement method for an aircraft engine crosswind test, comprising:

[0011] Step 1: Determine the environmental conditions for flow field measurement;

[0012] Step 2: Determine the flow field measurement requirements;

[0013] Step 3: Obtain measurement equipment and determine flow field measurement points;

[0014] Step 4: Conduct a crosswind test based on the environmental conditions, the flow field measurement requirements, the measurement equipment, and the flow field measurement points, and record flow field measurement data;

[0015] Step 5: Realize flow field measurement data processing.

[0016] In at least one embodiment of the present application, in step 1, the environmental conditions for flow field measurement include:

[0017] The ambient wind speed does not exceed 3m / s;

[0018] The ambient temperature is normal temperature;

[0019] Ambient humidity is within the range of 30%RH to 60%RH;

[0020] Flow field measurements are not performed under specific environments, including vibration, air pollution, rain, snow, sand and dust, and thunderstorms.

[0021] In at least one embodiment of the present application, in step 2, the flow field measurement requirements include:

[0022] Two angles, 90° and 180°, were selected as the working angles of the side wind device. When the side wind device was at 90°, the flow field measurement included: wind speed characteristic measurements of each section along the axis between the side wind device outlet and the test section; and wind speed characteristic measurements of the grid points on the test section. When the side wind device was at 180°, the flow field measurement included: wind speed characteristic measurements of the grid points on the test section.

[0023] The range of grid points selected on the test section covers the inlet section or nozzle section of the tested engine;

[0024] The number of sensors arranged on the test section shall be no less than 3 points, and they shall be able to characterize the wind speed within the cross-section. When the maximum dimension of the test section is within 2 meters, the number of sensors arranged shall be no less than 3 points. When the maximum dimension of the test section is more than 2 meters, the number of sensors arranged shall be increased by at least 1 for every additional meter.

[0025] The number of measured status points shall not be less than 10.

[0026] In at least one embodiment of the present application, in step three, the measuring device includes:

[0027] A base platform having a height of 3.1 m, a length of 6 m, and a width of 2 m, and an electric guide rail installed on the base platform;

[0028] A measuring frame, wherein the height of the measuring frame is 5.5 m, the measuring frame is mounted on the electric guide rail, and the movement distance of the measuring frame on the electric guide rail is 5.5 m;

[0029] The measuring device is also equipped with a pressure scanning valve, an anemometer, a wind vane sensor and a total static pressure probe;

[0030] There are two sets of measuring equipment, which are arranged in an alternating manner and can realize grid measurement with a span of 4.8m in height and 11m in length.

[0031] In at least one embodiment of the present application, in step three, the flow field measurement points include:

[0032] Each set of measuring equipment is equipped with 9 measuring points, which are arranged at intervals of 0.6m;

[0033] Each set of measuring equipment is provided with multiple test sections, wherein one measuring equipment is provided with 11 test sections and the other measuring equipment is provided with 10 test sections;

[0034] Each set of measuring equipment is equipped with 5 test positions along the outlet axis of the crosswind device.

[0035] In at least one embodiment of the present application, in step 5, the requirements for processing the flow field measurement data include:

[0036] The wind speed deviation measured by the two sets of measurement equipment at the same state point is within the range of ±1.0m / s, and the pressure deviation is within the range of ±0.5kPa;

[0037] After removing the bad points, the data of each point are averaged;

[0038] The wind speed, total pressure and static pressure curves are fitted by the data points, and the correlation coefficient R2 of the parameter curve is not less than 0.995;

[0039] The deviation between the wind speed calculated by the fitted parameter curve and the actual measured wind speed is no more than ±0.5m / s, and the pressure is no more than ±0.3kPa.

[0040] The invention has at least the following beneficial technical effects:

[0041] The flow field measurement method for aero-engine crosswind testing of the present application can measure the real flow field characteristics of the crosswind environment generated by the crosswind device; can obtain the boundary of the crosswind environment generated by the crosswind device and the range of the core wind speed zone; and can measure the flow field conditions around the engine for two actual working conditions with and without the engine on the test bench. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a schematic diagram of a measuring device according to one embodiment of the present application;

[0043] Figure 2 This is a schematic diagram of the arrangement of measuring points on a measuring device according to one embodiment of the present application;

[0044] Figure 3 This is a schematic diagram of the test section arrangement on the measuring device according to one embodiment of the present application;

[0045] Figure 4 This is a schematic diagram of the axial position of a measuring device according to one embodiment of the present application;

[0046] Figure 5 This is a wind speed distribution cloud map of one embodiment of the present application;

[0047] Figure 6 It is a wind speed characteristic curve of one embodiment of the present application. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below in conjunction with the drawings in the embodiments of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described embodiments are part of the embodiments of this application, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain this application, and should not be understood as limitations on this application. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The embodiments of this application are described in detail below in conjunction with the drawings.

[0049] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as limiting the scope of protection of this application.

[0050] The following is combined with Figures 1 to 6 This application is described in further detail.

[0051] The present application provides a flow field measurement method for an aircraft engine crosswind test, comprising the following steps:

[0052] Step 1: Determine the environmental conditions for flow field measurement;

[0053] Step 2: Determine the flow field measurement requirements;

[0054] Step 3: Obtain measurement equipment and determine flow field measurement points;

[0055] Step 4: Conduct a crosswind test based on environmental conditions, flow field measurement requirements, measurement equipment, and flow field measurement points, and record the flow field measurement data.

[0056] Step 5: Realize flow field measurement data processing.

[0057] In a preferred embodiment of the present application, in step 1, the environmental conditions for flow field measurement include:

[0058] The ambient wind speed does not exceed 3m / s;

[0059] The ambient temperature is normal temperature;

[0060] Ambient humidity is within the range of 30%RH to 60%RH;

[0061] Flow field measurements are not performed under specific circumstances, such as when there is large vibration, air pollution, rain, snow, sand and dust, thunderstorms, etc.

[0062] In a preferred embodiment of the present application, in step 2, the flow field measurement requirements include:

[0063] Two angles, 90° and 180°, were selected as the working angles of the side wind device. When the side wind device was at 90°, the flow field measurement included: wind speed characteristic measurements of each section along the axis between the side wind device outlet and the test section; and wind speed characteristic measurements of the grid points on the test section. When the side wind device was at 180°, the flow field measurement included: wind speed characteristic measurements of the grid points on the test section.

[0064] The range of grid points selected on the test section covers the inlet section or nozzle section of the tested engine;

[0065] The number of sensors arranged on the test section shall be no less than 3 points, and they shall be able to characterize the wind speed within the cross-section. When the maximum dimension of the test section is within 2 meters, the number of sensors arranged shall be no less than 3 points. When the maximum dimension of the test section is more than 2 meters, the number of sensors arranged shall be increased by at least 1 for every additional meter.

[0066] The number of measured status points shall not be less than 10.

[0067] In a preferred embodiment of the present application, the instruments used in the measuring equipment are shown in Table 1.

[0068] Table 1

[0069]

[0070] In this embodiment, the base platform has a height of 3.1 m, a length of 6 m, and a width of 2 m, and an electric guide rail is installed on the base platform; the height of the measuring frame is 5.5 m, and the measuring frame is installed on the electric guide rail. The measuring frame can achieve a span of 5.5 m on the electric guide rail; in addition, the measuring equipment is also equipped with a pressure scanning valve, an anemometer, a wind vane sensor, and a total static pressure probe; the measuring equipment includes two sets, and the two sets of measuring equipment are arranged in an staggered manner, which can achieve grid measurement with a height span of 4.8 m and a length span of 11 m.

[0071] In this embodiment, the arrangement of the flow field measurement points is as follows: 9 measurement points are set on each set of measuring equipment, and are arranged at intervals of 0.6m; each set of measuring equipment is set with multiple test sections, among which one measuring equipment is set with 11 test sections and the other measuring equipment is set with 10 test sections; each set of measuring equipment is set with 5 test positions along the outlet axis of the side wind device.

[0072] Specifically, the installation heights of the nine measuring points on each set of measuring equipment are shown in Table 2. This layout forms test points within the range of 3.6m to 8.4m in height (for measurement points within the range of 6m ± 2.4m at the center elevation).

[0073] Table 2

[0074] Measuring point number Layout height, m 1# measuring point 3.6 Measuring point 2# 4.2 3# measuring point 4.8 4# measuring point 5.4 5# measuring point 6.0 Measuring point 6# 6.6 7# measuring point 7.2 8# measuring point 7.8 9# measuring point 8.4

[0075] The test section set on each measuring device is as follows Figure 3 As shown in Figure 3, the left measurement device is set up with 11 sections and the right measurement device is set up with 10 sections. Section 0# is the wind farm central axis (vertical), and its transverse coordinate is set to 0 m. The physical position of each section relative to section 0# is shown in Table 3. This layout forms a test section within the range of 11 m in the longitudinal direction (for the test section within the range of -5.5 m to +5.5 m from the central axis).

[0076] Table 3

[0077]

[0078] In order to measure the flow field characteristics along the crosswind axis, five test positions were set along the axial direction of the crosswind device outlet. The distance between position 0 and the crosswind device outlet was 12 m. The distance information of each test position from the crosswind device outlet and position 0 is shown in Table 4.

[0079] Table 4

[0080] Test location number Distance from the crosswind device outlet, m Distance from position 0#, m 0#Test location 12 0 1# Test location 11 1 2# Test location 10 2 3# test position 13 -1 4# test position 14 -2

[0081] Place the flow field measurement equipment at the position specified above. Under the condition that the natural wind speed meets the calibration requirements, run the fan at various powers. After ensuring that the wind speed, total pressure, and static pressure are stable at each power, record the flow field measurement data. After completing the recording, switch to the next power until parameter collection is completed at all powers.

[0082] Finally, the flow field measurement data is processed. In the preferred embodiment of this application, the data processing requirements include:

[0083] The wind speed deviation measured by the two sets of measurement equipment at the same state point is within the range of ±1.0m / s, and the pressure deviation is within the range of ±0.5kPa;

[0084] After removing the bad points, the data of each point are averaged;

[0085] The wind speed, total pressure and static pressure curves are fitted by the data points, and the correlation coefficient R2 of the parameter curve is not less than 0.995;

[0086] The deviation between the wind speed calculated by the fitted parameter curve and the actual measured wind speed is no more than ±0.5m / s, and the pressure is no more than ±0.3kPa.

[0087] In one embodiment of the present application, multiple crosswind tests are carried out, and the specific application is as follows: crosswind flow field measurements are performed within a measurement cross section of 4.5 meters in height and 3.7 meters in width, and velocity distribution cloud maps within the measurement cross section are obtained under different wind speed conditions, such as Figure 5 As shown. And obtained as Figure 6 The wind speed characteristic curve is shown.

[0088] The flow field measurement method for aero-engine crosswind tests disclosed in this application can simultaneously obtain multiple parameters including velocity, total pressure, static pressure, etc. through a single measurement, and can comprehensively evaluate flow field characteristics without the need for multiple measurements, which is economical. A mobile measuring device is used to meet measurement requirements at any position, angle, and cross section, and the equipment has strong versatility. It also greatly shortens the measurement cycle and improves measurement efficiency. The flow field measurement method disclosed in this application is not limited by the state of the test bench, and can also be used to measure external flow field conditions under engine operating conditions. The crosswind flow field data obtained in this application can be used to support crosswind tests on engines, and can also be used to input numerical simulation conditions using the data, laying the foundation for test simulation. It has significant advantages and can break the gap in domestic crosswind flow field measurements.

[0089] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A flow field measurement method for aero-engine crosswind test, characterized in that: include: Step 1: Determine the environmental conditions for flow field measurement; Step 2: Determine the flow field measurement requirements; Step 3: Obtain measurement equipment and determine flow field measurement points; Step 4: Conduct a crosswind test based on the environmental conditions, the flow field measurement requirements, the measurement equipment, and the flow field measurement points, and record flow field measurement data; Step 5: Realize flow field measurement data processing; In step 1, the environmental conditions for flow field measurement include: The ambient wind speed does not exceed 3m / s; The ambient temperature is normal temperature; Ambient humidity is within the range of 30%RH to 60%RH; Do not perform flow field measurements under specific conditions, including vibration, air pollution, rain, snow, sand and dust, and thunderstorms; In step 2, flow field measurement requirements include: Two angles, 90° and 180°, were selected as the working angles of the side wind device. When the side wind device was at 90°, the flow field measurement included: wind speed characteristic measurements of each section along the axis between the side wind device outlet and the test section; and wind speed characteristic measurements of the grid points on the test section. When the side wind device was at 180°, the flow field measurement included: wind speed characteristic measurements of the grid points on the test section. The range of grid points selected on the test section covers the inlet section or nozzle section of the tested engine; The number of sensors arranged on the test section shall be no less than 3 points, and they shall be able to characterize the wind speed within the cross-section. When the maximum dimension of the test section is within 2 meters, the number of sensors arranged shall be no less than 3 points. When the maximum dimension of the test section is more than 2 meters, the number of sensors arranged shall be increased by at least 1 for every additional meter. The measured status points are no less than 10 points; In step 3, the measuring equipment includes: A base platform having a height of 3.1 m, a length of 6 m, and a width of 2 m, and an electric guide rail installed on the base platform; A measuring frame, wherein the height of the measuring frame is 5.5 m, the measuring frame is mounted on the electric guide rail, and the movement distance of the measuring frame on the electric guide rail is 5.5 m; The measuring device is also equipped with a pressure scanning valve, an anemometer, a wind vane sensor and a total static pressure probe; There are two sets of measuring equipment, which are arranged in an alternating manner and can realize grid measurement with a span of 4.8m in height and 11m in length.

2. The flow field measurement method for aeroengine crosswind test according to claim 1, characterized in that: In step 3, the flow field measurement points include: Each set of measuring equipment is equipped with 9 measuring points, which are arranged at intervals of 0.6m; Each set of measuring equipment is provided with multiple test sections, wherein one measuring equipment is provided with 11 test sections and the other measuring equipment is provided with 10 test sections; Each set of measuring equipment is equipped with 5 test positions along the outlet axis of the crosswind device.

3. The flow field measurement method for aeroengine crosswind test according to claim 2, characterized in that: In step 5, the requirements for flow field measurement data processing include: The wind speed deviation measured by the two sets of measurement equipment at the same state point is within the range of ±1.0m / s, and the pressure deviation is within the range of ±0.5kPa; After removing the bad points, the data of each point are averaged; The wind speed, total pressure and static pressure curves are fitted by the data points, and the correlation coefficient R2 of the parameter curve is not less than 0.995; The deviation between the wind speed calculated by the fitted parameter curve and the actual measured wind speed is no more than ±0.5m / s, and the pressure is no more than ±0.3kPa.

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