Pre-inlet flow tube area measurement method and system

Abstract

This application relates to a method and system for measuring the area of ​​a pre-inlet airflow duct. Based on the pre-inlet airflow duct area measurement device based on regional measuring points provided in this application, this application only needs to collect wind speed information from measuring points in the far-forward cross-section area. Using a layered calculation method, the pre-inlet airflow duct area can be calculated step by step outward along the measurement line from the engine axis center towards the inner wall of the test chamber. It has the advantages of simple measurement method and high measurement accuracy, improving the accuracy of aerodynamic additional drag calculation results. This technology can be used to determine the pre-inlet airflow duct area in the correction of aerodynamic additional drag on aero-engine test benches, solving the problem of accurate measurement of the pre-inlet airflow duct area and improving the accuracy of aerodynamic additional drag calculation.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of aero-engine test stand aerodynamic measurement, in particular to a pre-inlet flow pipe area measuring device based on regional measuring points, a method for using the same, a pre-inlet flow pipe area measuring method and system. BACKGROUND

[0002] When an aero-engine is tested in a test room, the thrust cannot be accurately measured due to the influence of air flow. Based on the momentum theorem and control volume, the thrust measurement is corrected by aerodynamic parameters in the test stand. The air flow entering the engine test room can be divided into primary flow and secondary flow. The primary flow enters the engine, and the secondary flow flows around the engine. The curved surface outlined by the flow line of the primary flow is called a pre-inlet flow pipe. The accurate pre-inlet flow pipe area, i.e. the inlet cross-section core area, needs to be obtained in the process of calculating the aerodynamic additional resistance. The pre-inlet flow pipe is a defined flow pipe, and the projection area of its cross section far in front changes with the average speed. Therefore, a certain iterative measurement and calculation are needed to accurately obtain the average speed and the corresponding pre-inlet flow pipe projection area.

[0003] For different types of engines, the pre-inlet flow pipe area is different under different working conditions. At present, in the correction of aerodynamic additional resistance, the pre-inlet flow pipe area is directly selected by experience. For example, in a 12m x 12m cross-section test room, the pre-inlet flow pipe area is determined according to a radius of 3.6m, and it is not determined by iteration according to the actual working condition, which will cause a large error and seriously affect the calculation result of the additional resistance. SUMMARY

[0004] To solve the above problems, the present application provides a pre-inlet flow pipe area measuring device based on regional measuring points, a method for using the same, and a pre-inlet flow pipe area measuring method and system, which are used to determine the pre-inlet flow pipe area in the correction of aerodynamic additional resistance of an aero-engine test stand, solve the problem of accurate measurement of the pre-inlet flow pipe area, and improve the calculation accuracy of aerodynamic additional resistance.

[0005] In one aspect of the present application, a pre-inlet flow pipe area measuring device based on regional measuring points is provided, comprising:

[0006] A wind speed measuring frame is arranged at the inlet cross-section position of the test room.

[0007] A measuring cross-section anemometer is installed on the wind speed measuring frame and is used to measure the wind flow speed through the inlet cross-section.

[0008] A temperature and humidity pressure sensor is installed in the test room and is used to measure the temperature and atmospheric pressure of the test room.

[0009] A data acquisition system is used to acquire and save data.

[0010] The measuring cross-section anemometer and the temperature and humidity pressure sensor are connected to the data acquisition system 4 respectively.

[0011] As an optional embodiment of the present application, 25 measuring cross-section anemometers are optionally installed on the wind speed measuring frame, and the measuring cross-section anemometers are uniformly arranged in a matrix on the wind speed measuring frame.

[0012] As an optional embodiment of the present application, the wind speed measuring frame is optionally installed at a position (4-9)D in front of the engine, and D is the diameter of the engine air intake flow pipe.

[0013] As an optional embodiment of the present application, the wind speed measuring frame is optionally installed vertically in front of the engine, and is perpendicular to the axis of the engine.

[0014] In another aspect of the present application, a use method of the above-mentioned pre-air flow pipe area measuring device based on regional measuring points is provided, and the use method comprises the following steps:

[0015] The pre-air flow pipe area measuring device based on regional measuring points is built, and the wind speed measuring frame of the device is installed at a position (4-9)D in front of the engine, and D is the diameter of the engine air intake flow pipe;

[0016] The data acquisition system of the device is used to prepare to collect wind speed signals, test chamber temperature signals and test chamber atmospheric pressure;

[0017] The safety of the instrument and equipment is checked;

[0018] The engine field test is carried out, the wind speed measurement of the cross-section regional measuring points of the wind speed measuring frame, the test chamber temperature and pressure measurement are completed, and the engine air intake flow is collected from the engine test stand;

[0019] The engine is stopped, data processing is carried out, and the pre-air flow pipe area is calculated.

[0020] In another aspect of the present application, a pre-air flow pipe area measuring method is also provided, which is implemented based on the above-mentioned pre-air flow pipe area measuring device based on regional measuring points, and comprises the following calculation steps:

[0021] S1, the measuring cross-section where the wind speed measuring frame is located is divided into n regions, and the areas of the regions are calculated respectively as A1, A2, …, An-1 and An;

[0022] S2, the test chamber density is calculated: the air flow density of the measuring cross-section is calculated by using the test chamber temperature T and the pressure P, and the air density of the test chamber is calculated according to formula (1)

[0023]

[0024] In the formula:

[0025] P——test chamber atmospheric pressure, Pa;

[0026] T——test chamber atmospheric temperature, K;

[0027] R——air gas constant, 287 J / (kg·K);

[0028] S3, calculate the average speed in each area and the area flow: find the wind speed measuring point in area 1, calculate the average wind speed in the area, which is v1, and the area flow is w1; find the wind speed measuring point in area 2, calculate the average wind speed in the area, which is v2, and the area flow is w2; …; find the wind speed measuring point in area n, calculate the average wind speed in the area, which is vn, and the area flow is wn; calculate the area flow according to formula (2):

[0029] w s = ρv s A s (2)

[0030] In the formula:

[0031] w s ——the flow of the s-th area, kg / s, s=1~n;

[0032] v s ——the average speed of the s-th area, m / s, s=1~n;

[0033] A s ——the area of the s-th area, m 2 , s=1~n;

[0034] S4, calculate the area cumulative flow and: W1=w1, W2=w1+w2, …, Wn-1=w1+w2+…+wn-1, Wn=w1+w2+…+wn-1+wn;

[0035] S5, determine the area of the pre-intake flow pipe according to the engine intake flow: collect the engine intake flow W0 from the engine test bench, compare W0 with each area cumulative flow in turn, find the interval Ws-1

[0036] S6, calculate the pre-intake flow pipe area: the pre-intake flow pipe area A is composed of area 1 area A1, area 2 area A2, …, area s-1 area As-1 and the annular area Ah in area s, Ah=(W0-Ws-1) / v3 / ρ, A=A1+A2+…+Ah.

[0037] As an optional implementation of this application, the measuring section where the wind speed measuring frame 1 is located may be divided into n regions, and the areas of each region are calculated as A1, A2, ..., An-1, An, including:

[0038] With the engine axis as the center, draw circles starting from the center of the measurement section. The radii of each circle are r1 = 0.1l, r2 = 0.2l, ..., rn-1 = 0.1(n-1)l, dividing the entire measurement section into n regions:

[0039] Region 1 is the inner diameter r i 1 = 0, outer diameter r o A circle where 1 = 0.1l;

[0040] Region 2 is the inner diameter r i 2 = 0.1l, outer diameter r o A ring with 2 = 0.2l;

[0041] ...;

[0042] Region n-1 is the inner diameter r i n-1=0.1(n-2)l、outer diameter r o A ring of n-1 = 0.1(n-1)l;

[0043] Region n represents the remaining portion of the measured cross section;

[0044] The areas of each region are A1, A2, ..., An-1, An, respectively.

[0045] l represents the side length of the measurement section.

[0046] In another aspect, this application also provides a pre-inlet airflow tube area measurement system, comprising:

[0047] processor;

[0048] Memory used to store processor-executable instructions;

[0049] The processor is configured to implement the pre-inlet airflow tube area measurement method described above when executing the executable instructions.

[0050] Technical effects of the present invention:

[0051] This application, based on the pre-inlet duct area measurement device provided in this application, only requires collecting wind speed information from measurement points in the far-forward cross-section area. Using a layered calculation method, the pre-inlet duct area can be calculated step-by-step outward from the measurement line along the engine axis center towards the inner wall of the test chamber. It has the advantages of simple measurement method and high measurement accuracy, improving the accuracy of aerodynamic additional drag calculation results. This technology can be used to determine the pre-inlet duct area in the correction of aerodynamic additional drag on aero-engine test benches, solving the problem of accurate measurement of the pre-inlet duct area and improving the accuracy of aerodynamic additional drag calculation.

[0052] Other features and aspects of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0053] The accompanying drawings, which are included in and form part of this specification, illustrate exemplary embodiments, features, and aspects of this disclosure together with the specification and serve to explain the principles of this disclosure.

[0054] Figure 1 The diagram shows the layout structure of the pre-inlet airflow tube area measurement device based on regional measuring points according to the present invention.

[0055] Implementation process diagram;

[0056] Figure 2 The example shown is an application system of the present invention. Detailed Implementation

[0057] Various exemplary embodiments, features, and aspects of this disclosure will now be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements that have the same or similar functions. Although various aspects of the embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.

[0058] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0059] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0060] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0061] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0062] Furthermore, to better illustrate this disclosure, numerous specific details are set forth in the following detailed description. Those skilled in the art will understand that this disclosure can be practiced without certain specific details. In some instances, methods, means, components, and circuits well known to those skilled in the art have not been described in detail in order to highlight the main points of this disclosure.

[0063] This application provides a pre-inlet duct area measurement device based on regional measuring points. It collects wind speed information from measuring points in a cross-sectional area far in front of the transmitter and employs a layered calculation method to calculate the pre-inlet duct area step by step outwards along the measurement line from the engine axis center towards the inner wall of the test chamber. This method has the advantages of simple measurement and high accuracy, improving the accuracy of aerodynamic drag calculation results. It solves the problem of accurate measurement of the pre-inlet duct area and improves the accuracy of aerodynamic drag calculation.

[0064] Example 1

[0065] This embodiment first requires providing a data acquisition device, which is placed in a test workshop to measure, collect, and calculate parameters of the pre-inlet airflow duct area of ​​the transmitter.

[0066] like Figure 1 As shown, this application proposes, in one aspect, a pre-inlet airflow tube area measurement device based on regional measuring points, comprising:

[0067] Wind speed measuring frame 1 is positioned at the air inlet section of the test chamber;

[0068] The cross-sectional anemometer 2 is installed on the anemometer frame 1 and is used to measure the airflow velocity through the air inlet section;

[0069] Temperature, humidity and pressure sensor 3 is installed in the test chamber to measure the temperature and atmospheric pressure of the test chamber;

[0070] Data acquisition system 4 is used to collect and save data;

[0071] The anemometer 2 measuring the cross-section and the temperature, humidity and pressure sensor 3 are respectively connected to the data acquisition system 4.

[0072] The wind speed measuring frame 1 is constructed using a dedicated anti-tipping bracket. In this embodiment, a 5*5 rod assembly is used to construct the wind speed measuring frame 1, which is positioned at the air intake section of the test workshop, directly opposite the pre-inlet airflow pipe opening of the engine. To ensure the uniformity of wind speed data collection, the wind speed measuring frame is installed at a position (4-9)D in front of the engine, where D is the diameter of the engine's air intake flow pipe.

[0073] On the cross-section where the wind speed measuring frame 1 is located, several anemometers 2 are evenly arranged. Each anemometer 2 is preferably a spherical anemometer to facilitate comprehensive wind speed data collection. Figure 2 The side view of the wind speed measuring frame 1 shown shows that 25 nodes are formed on the wind speed measuring frame 1, and a measuring cross-section anemometer 2 is installed on each node.

[0074] The temperature of the test chamber also needs to be measured, so a temperature, humidity, and pressure sensor 3 is installed inside the test chamber to measure the temperature and atmospheric pressure. The anemometer and the temperature, humidity, and pressure sensor are connected to the data acquisition system 4.

[0075] The model of the temperature, humidity and pressure sensor 3 is not limited in this embodiment.

[0076] The data acquisition system 4 is a data system configured by those skilled in the art, and this embodiment does not impose any limitations. After data acquisition, the data acquisition system 4 sends the data to a data processing system, such as data analysis software. Once the data is input, the pre-inlet airflow duct area can be obtained according to a preset algorithm.

[0077] As an optional embodiment of this application, optionally, 25 of the measuring cross-section anemometers 2 are installed on the wind speed measuring frame 1, and the measuring cross-section anemometers 2 are evenly arranged in a matrix on the wind speed measuring frame 1.

[0078] As an optional implementation of this application, the wind speed measuring frame 1 may be installed at a preset angle at a position (4-9)D in front of the engine, where D is the diameter of the engine intake airflow pipe.

[0079] As an optional embodiment of this application, the wind speed measuring frame 1 may be vertically mounted in front of the engine and perpendicular to the axis of the engine.

[0080] like Figure 1As shown, in this embodiment, the wind speed measuring frame 1 is preferably arranged vertically in front of the engine at a position (4-9)D, perpendicular to the axis of the engine.

[0081] In other implementation schemes, the axis of the engine can be tilted at a certain angle as required, and the specific angle can be set according to the requirements.

[0082] Once the above-mentioned device is set up, it can be started to prepare for engine startup and collect parameters for measuring the area of ​​the pre-inlet airflow pipe.

[0083] It should be noted that although the structure of the device for measuring the area of ​​the pre-inlet airflow tube has been described as an example, those skilled in the art will understand that this disclosure is not limited thereto. In fact, users can flexibly set the number of anemometers, the anemometer frame 1, etc., according to the actual application scenario, as long as the technical functions of this application can be achieved by following the above technical methods.

[0084] Example 2

[0085] Based on the implementation principle of Embodiment 1, this application, in another aspect, provides a method for using the pre-inlet airflow tube area measuring device based on regional measuring points described above, comprising the following steps:

[0086] A pre-inlet airflow pipe area measurement device based on regional measurement points is constructed. The wind speed measurement frame 1 of the device is installed at position (4-9)D in front of the engine, where D is the diameter of the engine airflow pipe.

[0087] The data acquisition system 4 of the device is prepared to collect wind speed signals, test chamber temperature signals, and test chamber atmospheric pressure.

[0088] Check the safety of the instruments and equipment;

[0089] The engine was tested on-site, and the wind speed, temperature and pressure in the test chamber were measured at the cross-sectional area of ​​the wind speed measuring frame 1. At the same time, the engine intake air flow was collected from the engine test bench.

[0090] The engine is stopped, data processing is performed, and the area of ​​the pre-inlet air duct is calculated.

[0091] The implementation of the above steps is specifically described in the structural description and usage of Embodiment 1. Steps involving engine testing and inspection can be performed by engine testing personnel according to requirements; this embodiment does not require such procedures.

[0092] Once the device is set up in the pilot plant, it is ready to collect data; after inspection, data collection begins; once data collection is complete, the data is saved to the data processing system.

[0093] Example 3

[0094] Based on the device provided in Embodiment 1 and the implementation method in Embodiment 2, the device is used to collect data and construct a data calculation model to obtain various parameters for area calculation.

[0095] In another aspect, this application also provides a method for measuring the area of ​​a pre-inlet airflow tube, implemented based on the aforementioned pre-inlet airflow tube area measuring device based on regional measuring points, comprising the following calculation steps:

[0096] S1. Divide the measuring section where the wind speed measuring frame 1 is located into n regions, and calculate the area of ​​each region as A1, A2, ..., An-1, An; specifically,

[0097] As an optional implementation of this application, the measuring section where the wind speed measuring frame 1 is located may be divided into n regions, and the areas of each region are calculated as A1, A2, ..., An-1, An, including:

[0098] With the engine axis as the center, draw circles starting from the center of the measurement section. The radii of each circle are r1 = 0.1l, r2 = 0.2l, ..., rn-1 = 0.1(n-1)l, dividing the entire measurement section into n regions:

[0099] Region 1 is the inner diameter r i 1 = 0, outer diameter r o A circle where 1 = 0.1l;

[0100] Region 2 is the inner diameter r i 2 = 0.1l, outer diameter r o A ring with 2 = 0.2l;

[0101] ...;

[0102] Region n-1 is the inner diameter r i n-1=0.1(n-2)l、outer diameter r o A ring of n-1 = 0.1(n-1)l;

[0103] Region n represents the remaining portion of the measured cross section;

[0104] The areas of each region are A1, A2, ..., An-1, An, respectively.

[0105] l represents the side length of the measurement section.

[0106] S2. Calculate the density of the test chamber: Calculate the air density at the measurement section using the test chamber temperature T and pressure P, and then calculate the air density of the test chamber according to formula (1).

[0107]

[0108] In the formula:

[0109] P—Atmospheric pressure in the test chamber, Pa;

[0110] T—Ambient temperature in the test workshop, K;

[0111] R—Gas constant for air, 287 J / (kg·K);

[0112] S3. Calculate the average velocity and regional flow rate in each region: Locate the wind speed measuring point in region 1, calculate the average wind speed in this region and record it as v1, and the regional flow rate as w1; Locate the wind speed measuring point in region 2, calculate the average wind speed in this region and record it as v2, and the regional flow rate as w2; ...; Locate the wind speed measuring point in region n, calculate the average wind speed in this region and record it as vn, and the regional flow rate as wn; Calculate the regional flow rate according to formula (2):

[0113] w s =ρv s A s (2)

[0114] In the formula:

[0115] w s —Flow rate of the s-th region, kg / s, s = 1 to n;

[0116] v s —The average velocity of the s-th region, m / s, s = 1 to n;

[0117] A s —The area of ​​the s-th region, m 2 , s = 1 ~ n;

[0118] S4. Calculate the cumulative flow of the region: W1 = w1, W2 = w1 + w2, ..., Wn-1 = w1 + w2 + ... + wn-1, Wn = w1 + w2 + ... + wn-1 + wn;

[0119] S5. Determine the region where the pre-intake airflow pipe is located based on the engine intake airflow: Collect the engine intake airflow W0 from the engine test bench, compare W0 with the cumulative flow of each region in turn, find the interval Ws-1 < W0 < Ws where W0 is located, and determine that the pre-intake airflow pipe is in region s.

[0120] S6. Calculate the area of ​​the pre-inlet airflow pipe: The area A of the pre-inlet airflow pipe is composed of the area A1 of region 1, the area A2 of region 2, ..., the area As-1 of region s-1 and the annular area Ah in region s, Ah = (W0-Ws-1) / v3 / ρ, A = A1+A2+...+Ah.

[0121] The following will use a test workshop with a cross-section of 12m×12m as an example to explain the method for measuring the area of ​​the pre-inlet airflow pipe.

[0122] a) If the measuring frame cross-section is divided into n=5 regions: with the engine axis as the center, draw circles starting from the center, with radii of r1=1.2m, r2=2.4m, r3=3.6m, and r4=4.8m respectively, dividing the entire cross-section into 5 regions. Region 1 is the region with an inner diameter r i 1 = 0, outer diameter r o 1. A circle with an inner diameter of 1.2m, and region 2 is a circle with an inner diameter of r. i 2 = 1.2m, outer diameter r o A circular ring with an inner diameter of 2.4m, region 3 being the inner diameter r. i 3 = 2.4m, outer diameter r o A circular ring with an inner diameter of 3.6m, region 4 being the inner diameter r. i 4 = 3.6m, outer diameter r o A ring with a diameter of 4.8m is formed. Region 5 represents the remaining portion of the cross-section. Each color represents a ring region, and the area of ​​each region is A1 = 4.52m². 2 A2 = 13.56m 2 A3 = 22.61m 2 A4 = 31.65m 2 A5 = 71.65m 2 .

[0123] b) Calculation of test chamber density: Using the test chamber temperature T and pressure P, the airflow density at the measuring frame cross-section was calculated to be ρ = 1.17 kg / m³. 3 .

[0124] c) Calculate the average speed and flow rate in each region: Locate the wind speed measuring point in region 1, calculate the average wind speed in this region as v1 = 9.1 m / s, and the regional flow rate as w1 = 48.11 kg / s; Locate the wind speed measuring point in region 2, calculate the average wind speed in this region as v2 = 9.1 m / s, and the regional flow rate as w2 = 144.39 kg / s; Locate the wind speed measuring point in region 3, calculate the average wind speed in this region as v3 = 9.2 m / s, and the regional flow rate as w3 = 243.23 kg / s; Locate the wind speed measuring point in region 4, calculate the average wind speed in this region as v4 = 8.6 m / s, and the regional flow rate as w4 = 318.29 kg / s; Locate the wind speed measuring point in region 5, calculate the average wind speed in this region as v5 = 8.89 m / s, and the regional flow rate as w5 = 745.25 kg / s.

[0125] d) Calculate the cumulative flow of the area: W1 = w1 = 48.11 kg / s, W2 = w1 + w2 = 192.5 kg / s, W3 = w1 + w2 + w3 = 435.72 kg / s, W4 = w1 + w2 + w3 + w4 = 754.02 kg / s, W5 = w1 + w2 + w3 + w4 + w5 = 1499.27 kg / s.

[0126] e) Determine the location of the pre-intake airflow pipe based on the engine intake airflow: The engine intake airflow W0 = 406.7 kg / s was collected from the engine test bench. W0 was compared with the cumulative flow of each region in turn. It was found that W2 < W0 < W3. Therefore, the pre-intake airflow pipe was determined to be in region 3.

[0127] f) Calculate the area of ​​the pre-inlet airflow duct: The area A of the pre-inlet airflow duct is composed of the area A1 of region 1, the area A2 of region 2, and the annular area Ah in region 3, Ah = (W0 - W2)

[0128] / v3 / ρ=19.90m 2 A = A1 + A2 + Ah = 37.98m 2 .

[0129] The specific calculation data for the pre-inlet airflow tube area are shown in Table 1 below:

[0130]

[0131] Table 1. Calculation Table for Pre-inlet Airflow Pipe Area

[0132] Obviously, those skilled in the art should understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the control methods described above. The modules or steps of the present invention described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. Optionally, they can be implemented using computer-executable program code, thereby storing them in a storage device for execution by a computing device, or fabricating them separately as individual integrated circuit modules, or fabricating multiple modules or steps into a single integrated circuit module. Thus, the present invention is not limited to any specific hardware and software combination.

[0133] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the control methods described above. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk drive (HDD), or solid-state drive (SSD), etc.; the storage medium can also include combinations of the above types of memory.

[0134] Example 4

[0135] Furthermore, in another aspect, this application also provides a pre-inlet airflow tube area measurement system, comprising:

[0136] processor;

[0137] Memory used to store processor-executable instructions;

[0138] The processor is configured to implement the pre-inlet airflow tube area measurement method described above when executing the executable instructions.

[0139] This disclosure discloses an embodiment of a control system including a processor and a memory for storing processor-executable instructions. The processor is configured to implement, when executing the executable instructions, any of the preceding descriptions of a pre-inlet airflow tube area measurement device based on a region measuring point.

[0140] It should be noted here that the number of processors can be one or more. Furthermore, the control system in this embodiment may also include input devices and output devices. The processors, memory, input devices, and output devices can be connected via a bus or other means, without specific limitations herein.

[0141] As a computer-readable storage medium, the memory can be used to store software programs, computer-executable programs, and various modules, such as the program or module corresponding to the pre-inlet airflow tube area measurement device based on regional measuring points according to embodiments of this disclosure. The processor executes various functional applications and data processing of the control system by running the software programs or modules stored in the memory.

[0142] Input devices can be used to receive input digital numbers or signals. These signals can be key signals related to user settings and function control of the device / terminal / server. Output devices can include display devices such as screens.

[0143] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical applications, or technical improvements to the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A pre-duct area measurement method, characterized by, The device comprises: A wind speed measuring frame arranged at the air intake section of the test chamber; A measuring section anemometer installed on the wind speed measuring frame for measuring the wind speed through the air intake section; A temperature and humidity pressure sensor installed in the test chamber for measuring the temperature and atmospheric pressure of the test chamber; A data acquisition system for acquiring and saving data; The measuring section anemometer and the temperature and humidity pressure sensor are connected to the data acquisition system; A wind speed measuring frame of the device is installed at the front (4-9)D position of the engine, where D is the diameter of the engine air flow pipe; The data acquisition system of the device is used to prepare for collecting wind speed signals, test chamber temperature signals and test chamber atmospheric pressure; The safety of the instrument and equipment is checked; The engine field test is conducted to complete the wind speed measurement of the cross section area measuring points of the wind speed measuring frame, the temperature and pressure measurement of the test chamber, and the engine air flow measurement from the engine test stand; The engine is stopped, and the data is processed to calculate the pre-air flow pipe area; The pre-air flow pipe area measurement includes the following calculation steps: S1, divide the measuring section where the wind speed measuring frame is located into n regions, and calculate the area of each region as A1, A2, …, An-1, An respectively; take the engine axis as the center, and make a circle from the center of the measuring section, and the radius of each circle is r1=0.1l, r2=0.2l, …, rn-1=0.1(n-1)l, and the entire measuring section is divided into n regions: Region 1 is a circle with an inner diameter r11=0 and an outer diameter r01=0.1l; ……； Region 2 is a circular ring with an inner diameter r12=0.1l and an outer diameter r02=0.2l; Region n-1 is a circular ring with an inner diameter rin-1=0.1(n-2)l and an outer diameter ron-1=0.1(n-1)l; and region n is the remaining part of the measuring section; The area of each region is A1, A2, …, An-1, An respectively; l is the side length of the measuring section; S2, calculate the density of the test chamber: calculate the air flow density of the measuring section by using the temperature T and pressure P of the test chamber, and calculate the air density of the test chamber according to formula (1) In the formula: P is the atmospheric pressure of the test chamber, Pa; T is the atmospheric temperature of the test chamber, K; R is the air gas constant, 287 J / (kg·K); S3, calculate the average speed and region flow rate: find the wind speed measuring points in region 1, calculate the average wind speed in the region as v1, and the region flow rate as w1; find the wind speed measuring points in region 2, calculate the average wind speed in the region as v2, and the region flow rate as w2; …; find the wind speed measuring points in region n, calculate the average wind speed in the region as vn, and the region flow rate as wn; According to formula (2), the region flow rate is calculated: w s - flow of the s-th region, kg / s, s = 1...n; v s - average speed of the s-th zone, m / s, s = 1 to n; A s Area of the s-th region, m2, s = 1 ~ n; In the formula: S4, calculate the region cumulative flow rate and: W1=w1, W2=w1+w2, …, Wn-1=w1+w2+…+wn-1, Wn=w1+w2+…+wn-1+wn; S5, determining the area of the pre-intake flow pipe according to the engine intake flow: collecting the engine intake flow W0 from the engine test bench, comparing W0 with the cumulative flow of each area in turn, finding the interval Ws-1 < W0 < Ws of W0, and determining that the pre-intake flow pipe is in the area s; S6, calculating the area of the pre-intake flow pipe: the area A of the pre-intake flow pipe is composed of the area A1 of the area 1, the area A2 of the area 2, …, the area As-1 of the area s-1 and the annular area Ah in the area s, Ah=(W0-Ws-1) / vs / ρ, A=A1+A2+…+Ah.

2. A method of measuring the area of a pre-swirl duct according to claim 1, wherein, 25 of the measurement cross-section anemometers are installed on the wind speed measuring frame, and the measurement cross-section anemometers are uniformly arranged on the wind speed measuring frame in a matrix manner.

3. A method of measuring the area of a pre-swirl duct according to claim 1, wherein, The wind speed measuring frame is installed in front of the engine according to a preset angle.

4. A method of measuring the area of a pre-swirl duct according to claim 3, wherein, The wind speed measuring frame is vertically installed in front of the engine and is perpendicular to the axis of the engine.

5. A pre-inlet flow tube area measurement system characterized by, Comprise: a processor; a memory for storing processor-executable instructions; wherein the processor is configured to implement the pre-intake flow pipe area measurement method of any one of claims 1-4 when executing the executable instructions.

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