CN114528778A - Air flow measurement method based on bell mouth flow tube speed distribution model - Google Patents

Air flow measurement method based on bell mouth flow tube speed distribution model Download PDF

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CN114528778A
CN114528778A CN202210076798.2A CN202210076798A CN114528778A CN 114528778 A CN114528778 A CN 114528778A CN 202210076798 A CN202210076798 A CN 202210076798A CN 114528778 A CN114528778 A CN 114528778A
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余楠兮
王毅
刘琳琳
王玉芳
杨振
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Beijing Changcheng Institute of Metrology and Measurement AVIC
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Abstract

The invention discloses an air flow measuring method based on a bell-mouth flow tube speed distribution model, and belongs to the field of measurement of air inflow of an aero-engine. The implementation method of the invention comprises the following steps: and determining the distribution range of the pressure measurement rake on the measurement section in the test according to the velocity distribution model in the pipe, then carrying out data measurement of a few points on the measurement section to obtain a complete velocity distribution model in the pipe, and carrying out integral calculation on the obtained complete velocity distribution model in the pipe to obtain the air flow in the pipe and realize the measurement of the air inlet flow of the aero-engine. The invention divides the velocity distribution model in the pipe into a constant section, a linear section and a logarithmic section, and selects the distribution range and the distribution quantity of the pressure measurement rake on the measurement section for calibrating the velocity distribution model in the pipe in sections according to the velocity distribution characteristics of each section, thereby realizing the accurate distribution of the measurement points, reducing the quantity of the measurement points, and improving the flow measurement precision and the measurement efficiency on the premise of ensuring the measurement precision of the air intake flow of the aeroengine.

Description

Air flow measurement method based on bell mouth flow tube speed distribution model
Technical Field
The invention belongs to the field of measurement of air inflow of an aircraft engine, and relates to an air flow measurement method based on a bell-mouth flow tube speed distribution model.
Background
The measurement result of the air intake flow of an aircraft engine is commonly used for performance evaluation and condition monitoring of the whole engine and parts, the most common measurement scheme at present is to measure by means of a bell-mouth flow tube equipped with a total static pressure probe, and the following two embodiments exist in the measurement method.
One is to obtain the flow in the pipe by the average condition of a few measuring points, wherein the measuring points are arranged in a small number for simple measurement. The scheme can not reflect the real pressure and speed distribution in the pipe, thereby causing inaccurate measuring results.
The other is to obtain the air flow in the tube by the annular area method. This method is to divide the cross section of the pipe into a central circle and a plurality of rings, using the center of the circle of the cross section of the pipe as the center, as shown in fig. 2. The velocity value measured in each ring is multiplied by the area of the ring, and all the results are added to obtain the volume flow in the pipe (see fig. 3). Theoretically, in the measuring method, accurate flow value in the pipe can be obtained only by arranging the measuring points densely enough. Therefore, in this scheme, for accurate measurement, the number of measurement points is increased to obtain the true velocity distribution in the pipe. It is often necessary to make more pressure measurement rakes with more densely packed stations or to manually remove the in-line measurement probe. Both of these cases can greatly increase labor, time, and process fabrication costs, which are difficult to achieve in actual field measurements.
Therefore, the invention provides a method for obtaining the complete velocity distribution in the pipe by measuring a few points in the pipe, and can conveniently and quickly obtain the accurate flow in the pipe.
Disclosure of Invention
In order to solve the problems of more measuring point arrangement and higher cost of labor, time, process and the like, the invention mainly aims to provide a flow measuring method based on a bell-mouth flow tube speed distribution model.
The purpose of the invention is realized by the following technical scheme.
The invention discloses an air flow measuring method based on a bell mouth flow pipe inner velocity distribution model, which comprises the following steps:
step one, aiming at the bell-mouth flow tube, an in-tube velocity distribution model is established, and measuring point arrangement ranges on all sections of the velocity distribution model are determined according to the established three-section in-tube velocity distribution model, namely the pressure measurement rake measuring point arrangement range and the number of measuring points in a test are determined.
Step 1.1: the velocity distribution model in the pipe is as the following formula (1), wherein D is the pipe diameter of the straight pipe section of the flow pipe; v. ofave、k1、k2A and b are undetermined function coefficients; r1、R2And R3The boundary location points of the different function segment intervals.
Figure BDA0003484375050000021
Step 1.2: the in-pipe speed distribution model is a three-section speed distribution model, and the arrangement range of pressure measurement rake measuring points and the number of the measuring points in the test are determined according to the three-section speed distribution model as follows: two measuring points are respectively arranged on the constant section (core area), the linear section (transition section) and the logarithmic section. The constant segment is 0-0.39D-0.45D, the linear segment is 0.39D-0.45D-0.4625D-0.465D, and the logarithmic segment is 0.4625D-0.465D-0.5D.
And secondly, numbering the measuring point arrangement range and the number of the measuring points determined in the step one, measuring the pressure distribution in the pipe in any flowing state, and measuring the atmospheric pressure and the absolute temperature in the test environment by an atmospheric pressure and temperature measuring device.
Step 2.1: setting measuring points according to the measuring point arrangement range determined in the step one, and installing a total pressure measuring device on a measuring section 1.5D away from the tail end of the inlet profile section of the flow tube, wherein: the total pressure measuring point numbers i of the core area are 1 and 2, the total pressure measuring point numbers i of the transition section are 3 and 4, and the total pressure measuring point numbers i of the logarithmic section are 5 and 6.
Step 2.2: measuring the pressure distribution in the pipe in any flow state, wherein the acquisition time is at least 1min, and obtaining a total pressure measurement value at each measurement point: the core region measures two sets of data as (r)1,p1*)、(r2,p2Two sets of data were obtained for the transition segment as (r)3,p3*)、(r4,p4Log segment measured two sets of data as (r)5,p5*)、(r6,p6X); meanwhile, on the measuring section, a static pressure value p on the section is obtained by a static pressure measuring devicet。
Step 2.3: measuring the atmospheric pressure p in the test environment by means of an atmospheric pressure and temperature measuring device0And the absolute temperature T.
And step three, processing the measured data to obtain the air density, the total pressure average value of each measuring point, the static pressure average value on the measuring section and the speed value of each measuring point under the test condition.
Step 3.1: the air density under the test conditions was calculated:
Figure BDA0003484375050000022
wherein the content of the first and second substances,
p0atmospheric pressure, Pa;
n is the molar mass of air, 28.965294 g/mol;
r is a gas constant of 8.3144621J/(mol.K);
t is the absolute temperature, K.
Step 3.2: calculating the average value of the total pressure of each measuring point:
Figure BDA0003484375050000031
wherein the content of the first and second substances,
Figure BDA0003484375050000032
the total pressure average value with the total pressure measuring point number of i is Pa;
m is the group number of total pressure data measured in the acquisition time;
n is the group number of total pressure data measured in the acquisition time and is an integer of 1-m;
Figure BDA0003484375050000033
the total pressure measurement value Pa of the nth data at the total pressure measurement point number i.
Step 3.3: calculating the average static pressure value on the measuring section:
Figure BDA0003484375050000034
wherein the content of the first and second substances,
pt-aveis the average static pressure, Pa;
m' is the number of groups of static pressure data measured in the acquisition time;
n 'is the serial number of the groups of the static pressure data measured in the acquisition time, and the value is an integer between 1 and m';
pt-n'is the measurement of the n' th group of data of static pressure, Pa.
Step 3.4: calculating to obtain speed values at each measuring point:
Figure BDA0003484375050000035
wherein v isiIs the speed value at the test point number i in the test, m/s.
And step four, substituting the data of the measuring points processed in the step three into the velocity distribution model in the pipe established in the step one, and calculating the undetermined coefficient.
Step 4.1: aiming at the constant segment part of the core area in the pipe, the speed distribution model is
Figure BDA0003484375050000036
Wherein R is1The boundary of the core area is obtained by solving the intersection point of the core area and the transition section speed distribution model.
Step 4.2: for the transitional linear segment portion, (r) is3,v3) And (r)4,v4) Two sets of data are substituted into a velocity distribution model v (r, theta) ═ k1r+k2,r∈[R1,R2) Solving the undetermined coefficient k1And k is2A value of (1), wherein R2The boundary of the logarithmic section is obtained by solving the intersection point of the velocity distribution model of the linear transition section and the logarithmic section.
Step 4.3: for the pair of log segments, will (r)5,v5) And (r)6,v6) Two sets of data are brought into a velocity distribution model
Figure BDA0003484375050000037
Solving the values of undetermined coefficients a and b; the integral boundary R is obtained by setting the speed value of the fitting function to 0 according to the nature of the logarithmic function3The position coordinates of (a).
And step five, establishing a complete velocity distribution model in the pipe for the undetermined coefficient obtained in the step four, and performing integral calculation on the complete velocity distribution model in the pipe to obtain the air flow in the pipe, so that the measurement of the air inlet flow of the aircraft engine is realized, and the flow measurement precision and the measurement efficiency are improved.
Step 5.1: according to the calculated undetermined coefficient obtained by calculation in the fourth step, the complete velocity distribution in the pipe is modeled as a formula (6):
Figure BDA0003484375050000041
step 5.2: according to the complete velocity distribution model in the pipe, the mass air flow in the pipe is obtained through the integration of the formula (7), namely the measurement of the air inlet flow of the aircraft engine is realized, and the flow measurement precision and the measurement efficiency are improved.
Figure BDA0003484375050000042
Wherein, B is an integral interval, namely a measuring section on the pipeline.
Has the advantages that:
1. the invention discloses a flow measurement method based on a bell-mouth flow tube speed distribution model, which comprises the steps of determining the distribution range of a pressure measurement rake on a measurement section in a test according to the in-tube speed distribution model, carrying out data measurement on a few points on the measurement section to obtain an in-tube complete speed distribution model, carrying out integral calculation on the obtained in-tube complete speed distribution model to obtain the air flow in a tube, realizing the measurement of the air inlet flow of an aero-engine, and improving the flow measurement precision and the measurement efficiency.
2. The invention discloses a flow measuring method based on a bell-mouth flow pipe speed distribution model, which divides the pipe speed distribution model into a constant section, a linear section and a logarithmic section through a large number of tests and data analysis, and selects the distribution range and the distribution number of pressure measuring rakes on a measuring section for calibrating the pipe speed distribution model in sections according to the speed distribution characteristics of the constant section (core area), the linear section (transition section) and the logarithmic section of the speed distribution model, thereby realizing the accurate distribution of measuring points, reducing the number of the measuring points and improving the flow measuring precision and the measuring efficiency on the premise of ensuring the measuring precision of the air intake flow of an aeroengine.
Drawings
FIG. 1 is a schematic flow diagram of a flow measurement method based on a bell-mouth flow tube velocity distribution model according to the present disclosure;
FIG. 2 is a schematic view of a measurement cross-sectional area segmentation;
FIG. 3 is a schematic diagram of measuring the flow rate in a pipe by a circular area method.
Detailed Description
The present invention will be further described with reference to the following examples.
Example 1:
in order to solve the problem of more measuring points when a bell-mouth flow tube is used for accurately measuring air flow, the diameter D of a pipeline is 400mm, a profile section is a twisted-pair profile, and a twisted-pair polar coordinate formula rho is adopted2＝r2The process of using the bell-mouth flow tube with 0.637D as r and 40mm flanging structure to measure the field air flow is illustrated by taking 0.637D as r in cos 2 theta. Meanwhile, an annular area method is used for measuring the air flow under the same flow state, and the two results are compared and analyzed.
As shown in fig. 1, the flow measurement method based on the bell mouth flow tube velocity distribution model disclosed in this embodiment specifically includes the following steps:
step one, aiming at the used bell-mouth flow tube, establishing a velocity distribution model in the tube, and determining the arrangement range of the measuring points on each section of the velocity distribution model, namely determining the arrangement range of the pressure difference measuring rake measuring points and the number of the measuring points in the test.
1. The velocity distribution in the pipe is modeled as follows (8), where vave、k1、k2A and b are undetermined function coefficients; r1、R2And R3The boundary location points of the different function segment intervals.
Figure BDA0003484375050000051
2. Aiming at the three-section velocity distribution model, determining the arrangement range of the measuring points on the pressure measuring rake and the number of the measuring points in the test as follows: the point distribution range of the constant section (core area) is 0-0.178 m, and the positions of 2 measuring points are 0.0688m and 0.1562 m; the distribution range of the linear section (transition section) is 0.178-0.185 m, and the positions of 2 measuring points are 0.1805m and 0.1845 m; the dot distribution range of the log is 0.185-0.2 m, and the positions of 2 measuring points are 0.1865m and 0.1985 m.
And secondly, numbering the measuring point arrangement range and the number of the measuring points determined in the step one, measuring the pressure distribution in the pipe in any flowing state, and measuring the atmospheric pressure and the absolute temperature in the test environment by an atmospheric pressure and temperature measuring device.
1. Setting measuring points according to the measuring point arrangement range determined in the step one, and installing a total pressure measuring device on a measuring section 1.5D (0.6m) away from the tail end of the molded surface section of the inlet section of the flow pipe, wherein: the total pressure measuring point numbers i of the core area are 1 and 2, the total pressure measuring point numbers i of the transition section are 3 and 4, and the total pressure measuring point numbers i of the logarithmic section are 5 and 6.
2. The pressure distribution in the pipe under the flowing state with the main flow speed of about 50m/s is measured, the acquisition time is 99s, the acquisition frequency is 1Hz, and the total pressure measurement value at each measuring point is obtained: the core region measures two sets of data as (r)1,p1*)、(r2,p2Linear segment measured two sets of data as (r)3,p3*)、(r4,p4Log segment measured two sets of data as (r)5,p5*)、(r6,p6X); meanwhile, on the measuring section, a static pressure value p on the section is obtained by a static pressure measuring devicet。
3. Measuring the atmospheric pressure p in the test environment by means of an atmospheric pressure and temperature measuring device0101150Pa and 284.5K.
And step three, processing the measured data to obtain the air density, the average total pressure value of each measuring point, the average static pressure value on the measuring section and the speed value of each measuring point under the test condition.
1. The air density under the experimental conditions was calculated:
Figure BDA0003484375050000052
2. calculating the average value of the total pressure of each measuring point:
Figure BDA0003484375050000053
the average total pressure at each measurement point is calculated as shown in the following table.
Total pressure measurement point number i 1 2 3 4 5 6
Measurement point position/m 0.0688 0.1562 0.1805 0.1845 0.1865 0.1985
Average total pressure/Pa 101166 101154 101102 101075 101054 100605
3. Calculating the average static pressure value on the measuring section:
Figure BDA0003484375050000061
4. calculating to obtain speed values at each measuring point:
Figure BDA0003484375050000062
total pressure measurement point number i 1 2 3 4 5 6
Measurement point position/m 0.0688 0.1562 0.1805 0.1845 0.1865 0.1985
Velocity value/(m/s) 46.9 46.7 45.8 45.3 45.0 36.0
Step four, substituting the data of each measuring point processed in the step three into the in-pipe velocity distribution model formula (8) established in the step one, and calculating a coefficient to be determined;
1. aiming at the constant segment part of the core area in the pipe, the speed distribution model is
Figure BDA0003484375050000063
2. For the transitional linear segment portion, (r) is3,v3) And (r)4,v4) Two sets of data are substituted into a velocity distribution model v (r, theta) ═ k1r+k2,r∈[R1,R2) Solving the undetermined coefficient k1-125 and k268.3625. At this time, R can be solved1＝0.1725m。
3. For the pair of log segments, will (r)5,v5) And (r)6,v6) Two sets of data are brought into a velocity distribution model
Figure BDA0003484375050000064
And solving the undetermined coefficient a-4.0961 and b-62.6339. At this time, R can be solved2＝0.1862m，R3＝0.19999977m。
And step five, establishing a complete velocity distribution model in the pipe for the undetermined coefficient obtained in the step four, and performing integral calculation on the complete velocity distribution model in the pipe to obtain the air flow in the pipe, so that the measurement of the air inlet flow of the aircraft engine is realized, and the flow measurement precision and the measurement efficiency are improved.
1. According to the calculation result in the fourth step, the velocity distribution can be expressed as the following formula:
Figure BDA0003484375050000065
2. the mass air flow in the tube is calculated by:
Figure BDA0003484375050000066
the calculation result is qm＝7.152kg/s。
Meanwhile, the air flow rate is measured by the annular area method for the same flow state. Here, 14 measuring points are arranged in the pipe, and the obtained calculation result is as follows: q. q ofm' -7.120 kg/s. With qm' for standard flow, the relative error between the measurement of the invention and the standard flow value can be found to be: 0.44 percent. According to the invention, the flow measurement result with the relative error with the standard flow within 0.5% can be obtained by using 6 measuring points, and the problems of more measuring point arrangements, higher cost of labor, time, process and the like in the conventional aeroengine air intake flow measurement are solved.
The above detailed description is intended to illustrate the objects, aspects and advantages of the present invention, and it should be understood that the above detailed description is only exemplary of the present invention and is not intended to limit the scope of the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (6)

1. An air flow measuring method based on a bell mouth flow pipe inner velocity distribution model is characterized in that: comprises the following steps of (a) carrying out,
step one, aiming at a bell-mouth flow tube, establishing a velocity distribution model in the tube, and determining the arrangement range of measuring points on each section of the velocity distribution model according to the established three-section velocity distribution model in the tube, namely determining the arrangement range of the measuring points of the pressure measurement rake and the number of the measuring points in the test;
step two, numbering the measuring point arrangement range and the number of the measuring points determined in the step one, measuring the pressure distribution in the pipe in any flowing state, and measuring the atmospheric pressure and the absolute temperature in the test environment by an atmospheric pressure and temperature measuring device;
processing the measured data to obtain the air density, the total pressure average value of each measuring point, the static pressure average value on the measuring section and the speed value of each measuring point under the test condition;
step four, substituting the data of each measuring point processed in the step three into the velocity distribution model in the pipe established in the step one, and calculating undetermined coefficients;
and step five, establishing a complete velocity distribution model in the pipe for the undetermined coefficient obtained in the step four, and performing integral calculation on the complete velocity distribution model in the pipe to obtain the air flow in the pipe, so that the measurement of the air inlet flow of the aircraft engine is realized, and the flow measurement precision and the measurement efficiency are improved.
2. The method of air flow measurement based on a model of velocity distribution in a bell-mouth flow tube of claim 1, wherein: the first implementation method comprises the following steps of,
step 1.1: the velocity distribution model in the pipe is as the following formula (1), wherein D is the pipe diameter of the straight pipe section of the flow pipe; v. ofave、k1、k2A and b are undetermined function coefficients; r1、R2And R3Then the boundary position points of different function segment intervals are obtained;
Figure FDA0003484375040000011
step 1.2: the in-pipe speed distribution model is a three-section speed distribution model, and the arrangement range of pressure measurement rake measuring points and the number of the measuring points in the test are determined according to the three-section speed distribution model as follows: two measuring points are respectively arranged on the constant section (core area), the linear section (transition section) and the logarithmic section; the constant segment is 0-0.39D-0.45D, the linear segment is 0.39D-0.45D-0.4625D-0.465D, and the logarithmic segment is 0.4625D-0.465D-0.5D.
3. The method of air flow measurement based on a model of velocity distribution in a bell-mouth flow tube of claim 2, wherein: the second step is realized by the method that,
step 2.1: setting measuring points according to the measuring point arrangement range determined in the step one, and installing a total pressure measuring device on a measuring section 1.5D away from the tail end of the inlet profile section of the flow tube, wherein: the total pressure measuring point numbers i of the core area are 1 and 2, the total pressure measuring point numbers i of the transition section are 3 and 4, and the total pressure measuring point numbers i of the logarithmic section are 5 and 6;
step 2.2: measuring the pressure distribution in the pipe in any flow state, wherein the acquisition time is at least 1min, and obtaining a total pressure measurement value at each measurement point: the core region measures two sets of data as (r)1,p1*)、(r2,p2Two sets of data were obtained for the transition segment as (r)3,p3*)、(r4,p4Log segment measured two sets of data as (r)5,p5*)、(r6,p6X); meanwhile, on the measuring section, a static pressure value p on the section is obtained by a static pressure measuring devicet；
Step 2.3: measuring the atmospheric pressure p in the test environment by means of an atmospheric pressure and temperature measuring device0And the absolute temperature T.
4. A method of air flow measurement based on a model of velocity distribution in a bell-mouth flow tube as set forth in claim 3 wherein: the third step is to realize the method as follows,
step 3.1: the air density under the test conditions was calculated:
Figure FDA0003484375040000021
wherein the content of the first and second substances,
p0atmospheric pressure, Pa;
n is the molar mass of air, g/mol;
r is a gas constant, J/(mol. K);
t is absolute temperature, K;
step 3.2: calculating the average value of the total pressure of each measuring point:
Figure FDA0003484375040000022
wherein the content of the first and second substances,
Figure FDA0003484375040000023
the total pressure average value with the total pressure measuring point number of i is Pa;
m is the group number of total pressure data measured in the acquisition time;
n is the group number of total pressure data measured in the acquisition time and is an integer of 1-m;
Figure FDA0003484375040000024
numbering i positions of the total pressure measuring points, the total pressure measuring value Pa of the nth group of data;
step 3.3: calculating the average static pressure value on the measuring section:
Figure FDA0003484375040000025
wherein the content of the first and second substances,
pt-aveis the average static pressure, Pa;
m' is the number of groups of static pressure data measured in the acquisition time;
n 'is the serial number of the groups of the static pressure data measured in the acquisition time, and the value is an integer between 1 and m';
pt-n'is the measured value of the nth' group of data of static pressure, Pa;
step 3.4: calculating to obtain speed values at each measuring point:
Figure FDA0003484375040000031
wherein v isiIs the speed value at the test point number i in the test, m/s.
5. The method of air flow measurement based on a model of velocity distribution in a bell-mouth flow tube of claim 4, wherein: the implementation method of the fourth step is that,
step 4.1: aiming at the constant segment part of the core area in the pipe, the speed distribution model is
Figure FDA0003484375040000032
Wherein R is1Obtaining the boundary of the core area by solving the intersection point of the core area and the transition section speed distribution model;
step 4.2: for the transitional linear segment portion, (r) is3,v3) And (r)4,v4) Two sets of data are substituted into a velocity distribution model v (r, theta) ═ k1r+k2,r∈[R1,R2) Solving the undetermined coefficient k1And k is2A value of (1), wherein R2The boundary of the logarithmic section is obtained by solving the intersection point of the linear transition section and the logarithmic section speed distribution model;
step 4.3: for the pair of log segments, will (r)5,v5) And (r)6,v6) Two sets of data are brought into a velocity distribution model
Figure FDA0003484375040000033
Solving the values of undetermined coefficients a and b; the integral boundary R is obtained by setting the speed value of the fitting function to 0 according to the nature of the logarithmic function3The position coordinates of (a).
6. The method of air flow measurement based on a model of velocity distribution in a bell-mouth flow tube of claim 5, wherein: the fifth step is to realize that the method is that,
step 5.1: according to the calculated undetermined coefficient obtained by calculation in the fourth step, the complete velocity distribution in the pipe is modeled as a formula (6):
Figure FDA0003484375040000034
step 5.2: according to the complete velocity distribution model in the pipe, the mass air flow in the pipe is obtained through the integration of the formula (7), namely the measurement of the air inlet flow of the aircraft engine is realized, and the flow measurement precision and the measurement efficiency are improved;
Figure FDA0003484375040000035
wherein, B is an integral interval, namely a measuring section on the pipeline.
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CN116399412A (en) * 2023-06-06 2023-07-07 山东蓝想环境科技股份有限公司 Method for measuring air quantity in pipeline of filling experiment platform

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20170316133A1 (en) * 2016-01-20 2017-11-02 Soliton Holdings Corporation, Delaware Corporation Generalized Jet-Effect
CN107576361A (en) * 2017-09-01 2018-01-12 中国航空工业集团公司北京长城计量测试技术研究所 A kind of heavy caliber pipeline flow measurement device based on LDV
CN111859662A (en) * 2020-07-17 2020-10-30 泰州市都瑞堡船舶设备有限公司 Layout method of uniform velocity tube flowmeter in variable air volume air conditioner tail end unit
CN113029502A (en) * 2021-04-20 2021-06-25 中国空气动力研究与发展中心高速空气动力研究所 Nacelle wind tunnel test method for simultaneously simulating air intake and air exhaust
CN113125103A (en) * 2021-03-24 2021-07-16 中国空气动力研究与发展中心空天技术研究所 Data processing method for elliptical cross-section flow meter with 41 measuring points equidistantly distributed

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20170316133A1 (en) * 2016-01-20 2017-11-02 Soliton Holdings Corporation, Delaware Corporation Generalized Jet-Effect
CN107576361A (en) * 2017-09-01 2018-01-12 中国航空工业集团公司北京长城计量测试技术研究所 A kind of heavy caliber pipeline flow measurement device based on LDV
CN111859662A (en) * 2020-07-17 2020-10-30 泰州市都瑞堡船舶设备有限公司 Layout method of uniform velocity tube flowmeter in variable air volume air conditioner tail end unit
CN113125103A (en) * 2021-03-24 2021-07-16 中国空气动力研究与发展中心空天技术研究所 Data processing method for elliptical cross-section flow meter with 41 measuring points equidistantly distributed
CN113029502A (en) * 2021-04-20 2021-06-25 中国空气动力研究与发展中心高速空气动力研究所 Nacelle wind tunnel test method for simultaneously simulating air intake and air exhaust

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
李亚晋等: "一种用于发动机进气流量管校准的缩比模型实验装置", 《计测技术》 *
李冰等: "航空发动机进口空气流量测量方案分析", 《燃气涡轮试验与研究》 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116399412A (en) * 2023-06-06 2023-07-07 山东蓝想环境科技股份有限公司 Method for measuring air quantity in pipeline of filling experiment platform
CN116399412B (en) * 2023-06-06 2023-09-29 山东蓝想环境科技股份有限公司 Method for measuring air quantity in pipeline of filling experiment platform

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