Gas leakage rate measurement test device and method for low-altitude wind tunnel spraying and ice crystal system

Abstract

The invention provides a gas leakage rate measurement test device and method for a low-altitude wind tunnel spraying and ice crystal system, and belongs to the technical field of wind tunnel tests. The invention aims to solve the problem that the quantity value of gas sprayed into a wind tunnel by a spraying and ice crystal system cannot be directly measured in the prior art. A wind tunnel body, a wind tunnel test section and a wind tunnel power section are connected in sequence, and a vacuum system and a refrigeration system are installed on the wind tunnel body; three pressure transmitters and three temperature transmitters are arranged on the wind tunnel test section along the axis, and the second pressure transmitter and the second temperature transmitter are arranged at the midpoint of the wind tunnel test section. The first pressure transmitter, the third pressure transmitter, the second pressure transmitter, the first temperature transmitter, the third temperature transmitter and the second temperature transmitter are arranged at equal intervals; and the spraying and ice crystal system is arranged between the second temperature transmitter and the third temperature transmitter. The problem that in the prior art, the quantity value of gas sprayed into a wind tunnel by a spraying and ice crystal system cannot be directly measured is solved.

Description

Technical Field

[0001] This invention belongs to the field of wind tunnel testing technology, and particularly relates to a test device and method for measuring the leakage rate of low-altitude wind tunnel spray and ice crystal systems. Background Technology

[0002] With the rapid development of aerospace technology, research on extreme high-altitude environments is becoming increasingly in-depth. Among these researches, the study of the icing of aircraft engines by supercooled water droplets and ice crystals from high-altitude sprays has become a key research area in the aviation field of various countries. As a core experimental facility for simulating high-altitude low-temperature and low-pressure icing environments, the low-pressure wind tunnel is a crucial platform for conducting such research, and the stability of its experimental environment directly determines the reliability of the experimental data.

[0003] During the experiment, the spray and ice crystal system continuously injects a large amount of gas into the low-pressure wind tunnel. Due to the inherent design characteristics of the spray and ice crystal system, the amount of gas injected into the wind tunnel cannot be directly measured. This results in the vacuum system being unable to provide the optimal matching unit and matching opening, which in turn increases the difficulty of control and leads to unnecessary energy waste.

[0004] In summary, there is an urgent need to design a test device and method for measuring the leakage rate of low-altitude wind tunnel spray and ice crystal systems, in order to solve the problem that the amount of gas injected into the wind tunnel by the spray and ice crystal system cannot be directly measured in the existing technology. Summary of the Invention

[0005] A brief overview of the invention is given below to provide a basic understanding of certain aspects of it. It should be understood that this overview is not an exhaustive summary of the invention. It is not intended to identify key or essential parts of the invention, nor is it intended to limit the scope of the invention. Its purpose is merely to present certain concepts in a simplified form as a prelude to the more detailed description that follows.

[0006] In view of this, in order to solve the problem that the amount of gas injected into the wind tunnel by the spray and ice crystal system cannot be directly measured in the prior art, the present invention provides a test device and method for measuring the leakage rate of the low-altitude wind tunnel spray and ice crystal system.

[0007] Option 1: Leakage rate measurement test device for low-altitude wind tunnel spray and ice crystal system, including wind tunnel body, wind tunnel test section, wind tunnel power section, spray and ice crystal system, vacuum system, and refrigeration system;

[0008] The wind tunnel body, wind tunnel test section and wind tunnel power section are connected in sequence, and a vacuum system and a refrigeration system are installed on the wind tunnel body;

[0009] The wind tunnel test section is equipped with a first pressure transmitter, a second pressure transmitter, a third pressure transmitter, a first temperature transmitter, a second temperature transmitter, and a third temperature transmitter arranged along the axis. The second pressure transmitter and the second temperature transmitter are located at the midpoint of the wind tunnel test section. The first pressure transmitter, the third pressure transmitter, and the second pressure transmitter are equidistant from each other. The first temperature transmitter, the third temperature transmitter, and the second temperature transmitter are also equidistant from each other.

[0010] The spray and ice crystal system is located between the second and third temperature transmitters.

[0011] Furthermore, an air intake switch valve is installed between the spray and ice crystal system and the wind tunnel test section.

[0012] Furthermore, a high-pressure gas regulating valve is provided between the spray and ice crystal system and the air intake switch valve.

[0013] Furthermore, an air extraction regulating valve is provided between the wind tunnel body and the vacuum system.

[0014] Furthermore, the first pressure transmitter and the third temperature transmitter, the second pressure transmitter and the second temperature transmitter, and the third pressure transmitter and the first temperature transmitter are respectively arranged opposite to each other.

[0015] Option 2: A test method for measuring the leakage rate of a low-altitude wind tunnel spray and ice crystal system, which is based on the leakage rate measurement test device described in Option 1, and specifically includes the following steps:

[0016] S1. Start the fan in the wind tunnel power section to generate airflow in the wind tunnel body and wind tunnel test section. Then start the cooling system to lower the airflow temperature inside the wind tunnel. After the temperature stabilizes, measure the ambient temperature of the wind tunnel test section using the first, second, and third temperature transmitters. The measured temperatures are T1, T2, and T3, respectively. Therefore, the wind tunnel temperature T... 风洞 = (T1+T2+T3) / 3; When conducting environmental tests in the wind tunnel, the values ​​measured in the wind tunnel test section shall prevail;

[0017] S2. Establishing a vacuum environment: The wind tunnel is evacuated using a vacuum system and pumping valves, according to the formula P=P0×(1-2.25577×10). -5 ×h) 5.25588 Where P0 = 101325 Pa (normal pressure), P is the atmospheric pressure value at an altitude of h, and P can be measured by the first pressure transmitter, the second pressure transmitter, and the third pressure transmitter.

[0018] The values ​​measured by the first pressure transmitter, the second pressure transmitter, and the third pressure transmitter are P1, P2, and P3, respectively. Then P = (P1 + P2 + P3) / 3.

[0019] S3. Conduct a pressure test on the wind tunnel and simultaneously measure the air leakage at different altitudes in real time: First, measure the temperature and corresponding air density inside the wind tunnel at different altitudes in real time. The calculation process is shown below:

[0020] ρ 空气 =1.293×(P / P0)×(273.15 / K 实际绝对 ①;

[0021] K 实际绝对 =T 风洞 +273.15 ②;

[0022] Where, ρ 空气 P is the air density, P is the atmospheric pressure at an altitude of h, P0 is the standard physical atmospheric pressure, and K is the atmospheric pressure. 实际绝对 This refers to the actual absolute temperature.

[0023] The formula for calculating wind tunnel leakage is: △m 风洞 =(ρ2-ρ1)V 风洞容积 ③;

[0024] Where ρ1 is the air density of the first sample, ρ2 is the air density of the second sample, and V 风洞容积 For the wind tunnel volume, Δm 风洞 The air leakage rate in real time for maintaining pressure in the wind tunnel;

[0025] S4. Measure the leakage rate of the spray and ice crystal system: Repeat S3, turn on the spray and ice crystal system during pressure holding, and adjust the air intake rate of the spray and ice crystal system by opening the air intake switch valve and the high-pressure gas regulating valve. At this time, measure the amount of gas mixed into the spray and ice crystal system in real time, Δm. 混 The calculation method is the same as △m 风洞 The method is the same;

[0026] S5. Calculate the leakage rate Δm of the spray and ice crystal system. 喷雾及冰晶 ;

[0027] △m 喷雾及冰晶 =△m 混 -△m 风洞 ④.

[0028] The present invention has the following advantages over the prior art:

[0029] 1. This invention indirectly calculates the leakage by measuring the temperature and pressure inside the wind tunnel, solving the technical problem that the amount of gas injected into the low-pressure wind tunnel by the spray system and ice crystal system cannot be directly measured, and breaking through the measurement limitations of existing test devices.

[0030] 2. This invention can acquire the wind tunnel intake volume in real time, providing accurate control basis for the vacuum system, facilitating the selection of the best matching unit and matching opening degree for the vacuum system, significantly reducing the difficulty of wind tunnel pressure control, and improving the stability and control accuracy of test environment parameters;

[0031] 3. This invention avoids the vacuum system from being in a suboptimal operating state for a long time, reduces unnecessary energy waste and equipment wear, and improves the operational economy and reliability of low-pressure wind tunnel icing tests;

[0032] 4. This invention provides precise and stable test conditions for engine icing tests under high-altitude spray supercooled water droplets and ice crystal environments, which helps improve the accuracy of test data and ensures the efficient conduct of icing research in extreme environments. Attached Figure Description

[0033] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0034] Figure 1 A schematic diagram of the structure of the test device for measuring the leakage rate of a low-altitude wind tunnel spray and ice crystal system.

[0035] In the diagram: 1-Wind tunnel body, 2-First pressure transmitter, 3-Second pressure transmitter, 4-Third pressure transmitter, 5-First temperature transmitter, 6-Second temperature transmitter, 7-Spray and ice crystal system, 8-Inlet switch valve, 9-Third temperature transmitter, 10-High pressure gas regulating valve, 11-Wind tunnel test section, 12-Wind tunnel power section, 13-Vacuum system, 14-Ejection regulating valve, 15-Refrigeration system. Detailed Implementation

[0036] To make the technical solutions and advantages of the embodiments of the present invention clearer, the exemplary embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not an exhaustive list of all embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0037] Example 1, Reference Figure 1 This embodiment describes a low-altitude wind tunnel spray and ice crystal system leakage rate measurement test device, which includes a wind tunnel body 1, a wind tunnel test section 11, a wind tunnel power section 12, a spray and ice crystal system 7, a vacuum system 13, and a refrigeration system 15.

[0038] The wind tunnel body 1, the wind tunnel test section 11 and the wind tunnel power section 12 are connected in sequence. A vacuum system 13 and a refrigeration system 15 are installed on the wind tunnel body 1.

[0039] The wind tunnel test section 11 is equipped with a first pressure transmitter 2, a second pressure transmitter 3, a third pressure transmitter 4, a first temperature transmitter 5, a second temperature transmitter 6, and a third temperature transmitter 9 arranged along the axis. The second pressure transmitter 3 and the second temperature transmitter 6 are located at the midpoint of the wind tunnel test section 11. The first pressure transmitter 2, the third pressure transmitter 4, and the second pressure transmitter 3 are equidistant from each other. The first temperature transmitter 5, the third temperature transmitter 9, and the second temperature transmitter 6 are equidistant from each other.

[0040] The spray and ice crystal system 7 is located between the second temperature transmitter 6 and the third temperature transmitter 9.

[0041] Furthermore, an air intake switch valve 8 is installed between the spray and ice crystal system 7 and the wind tunnel test section 11.

[0042] Furthermore, a high-pressure gas regulating valve 10 is provided between the spray and ice crystal system 7 and the air intake switch valve 8.

[0043] Furthermore, an air extraction regulating valve 14 is provided between the wind tunnel body 1 and the vacuum system 13.

[0044] Furthermore, the first pressure transmitter 2 and the third temperature transmitter 9, the second pressure transmitter 3 and the second temperature transmitter 6, and the third pressure transmitter 4 and the first temperature transmitter 5 are respectively arranged opposite to each other.

[0045] Example 2, Reference Figure 1 This embodiment describes the test method for measuring the leakage rate of a low-altitude wind tunnel spray and ice crystal system. It is based on the leakage rate measurement test device described in Embodiment 1 and specifically includes the following steps:

[0046] S1. Start the fan in the wind tunnel power section 12 to generate airflow in the wind tunnel body 1 and the wind tunnel test section 11. Then start the cooling system 15 to lower the airflow temperature inside the wind tunnel. After the temperature stabilizes, measure the ambient temperature of the wind tunnel test section 11 using the first temperature transmitter 5, the second temperature transmitter 6, and the third temperature transmitter 9. The measured temperatures are T1, T2, and T3, respectively. Then, the wind tunnel temperature T 风洞 = (T1+T2+T3) / 3; When conducting environmental tests in the wind tunnel, the values ​​measured in wind tunnel test section 11 shall be taken as the standard;

[0047] S2. Establishing a vacuum environment: The wind tunnel body 1 is evacuated using the vacuum system 13 and the evacuation regulating valve 14, according to the formula P=P0×(1-2.25577×10). -5 ×h) 5.25588Where P0 = 101325 Pa (normal pressure), P is the atmospheric pressure value at an altitude of h, and P can be measured by the first pressure transmitter 2, the second pressure transmitter 3, and the third pressure transmitter 4.

[0048] The values ​​measured by the first pressure transmitter 2, the second pressure transmitter 3, and the third pressure transmitter 4 are P1, P2, and P3 respectively. Then P = (P1 + P2 + P3) / 3.

[0049] S3. Conduct a pressure test on the wind tunnel and simultaneously measure the air leakage at different altitudes in real time: First, measure the temperature and corresponding air density inside the wind tunnel at different altitudes in real time. The calculation process is shown below:

[0050] ρ 空气 =1.293×(P / P0)×(273.15 / K 实际绝对 ①;

[0051] K 实际绝对 =T 风洞 +273.15 ②;

[0052] Where, ρ 空气 P is the air density, P is the atmospheric pressure at an altitude of h, P0 is the standard physical atmospheric pressure, and K is the atmospheric pressure. 实际绝对 This refers to the actual absolute temperature.

[0053] The formula for calculating wind tunnel leakage is: △m 风洞 =(ρ2-ρ1)V 风洞容积 ③;

[0054] Where ρ1 is the air density of the first sample, ρ2 is the air density of the second sample, and V 风洞容积 For the wind tunnel volume, Δm 风洞 This formula represents the real-time air leakage rate for maintaining pressure in a wind tunnel. Based on this formula, the gas leakage rate in a wind tunnel at different altitudes and temperatures can be measured in real time.

[0055] S4. Measure the leakage rate of the spray and ice crystal system 7: Repeat S3, turn on the spray and ice crystal system 7 during pressure holding, and adjust the intake rate of the spray and ice crystal system 7 by opening the intake switch valve 8 and the high-pressure gas regulating valve 10. At this time, measure the amount of gas mixed into the spray and ice crystal system 7 in real time, Δm. 混 The calculation method is the same as △m 风洞 The method is the same;

[0056] S5. Calculate the leakage rate Δm of the spray and ice crystal system 7. 喷雾及冰晶 ;

[0057] △m 喷雾及冰晶 =△m 混 -△m 风洞④.

[0058] This invention indirectly calculates the leakage by measuring the temperature and pressure inside the wind tunnel, solving the technical problem that the amount of gas injected into the low-pressure wind tunnel by the spray system and ice crystal system cannot be directly measured, and breaking through the measurement limitations of existing test devices; at the same time, it can obtain the wind tunnel intake in real time, providing accurate control basis for the vacuum system, making it easier for the vacuum system to select the best matching unit and matching opening, significantly reducing the difficulty of wind tunnel pressure control, and improving the stability and control accuracy of test environment parameters;

[0059] This invention avoids the vacuum system from operating in a suboptimal state for extended periods, reducing unnecessary energy waste and equipment wear, and improving the operational economy and reliability of low-pressure wind tunnel icing tests. Simultaneously, it provides precise and stable test conditions for engine icing tests under high-altitude spray supercooled water droplets and ice crystal environments, which helps improve the accuracy of test data and ensures the efficient conduct of icing research in extreme environments.

[0060] Although the invention has been described with reference to a limited number of embodiments, those skilled in the art will understand from the foregoing description that other embodiments are conceivable within the scope of the invention described herein. Furthermore, it should be noted that the language used in this specification has been chosen primarily for readability and instructional purposes, and not for the purpose of interpreting or limiting the subject matter of the invention. Therefore, many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the appended claims. The disclosure of the invention is illustrative and not restrictive, and the scope of the invention is defined by the appended claims.

Claims

1. A test device for measuring the leakage rate of a low-altitude wind tunnel spray and ice crystal system, characterized in that, It includes the wind tunnel body (1), the wind tunnel test section (11), the wind tunnel power section (12), the spray and ice crystal system (7), the vacuum system (13), and the refrigeration system (15); The wind tunnel body (1), wind tunnel test section (11) and wind tunnel power section (12) are connected in sequence, and a vacuum system (13) and a refrigeration system (15) are installed on the wind tunnel body (1). The wind tunnel test section (11) is equipped with a first pressure transmitter (2), a second pressure transmitter (3), a third pressure transmitter (4), a first temperature transmitter (5), a second temperature transmitter (6), and a third temperature transmitter (9) arranged along the axis. The second pressure transmitter (3) and the second temperature transmitter (6) are located at the midpoint of the wind tunnel test section (11). The first pressure transmitter (2), the third pressure transmitter (4), and the second pressure transmitter (3) are equidistant from each other. The first temperature transmitter (5), the third temperature transmitter (9), and the second temperature transmitter (6) are equidistant from each other. The spray and ice crystal system (7) is located between the second temperature transmitter (6) and the third temperature transmitter (9).

2. The leakage rate measurement and testing device for the low-altitude wind tunnel spray and ice crystal system according to claim 1, characterized in that, An air intake switch valve (8) is installed between the spray and ice crystal system (7) and the wind tunnel test section (11).

3. The leakage rate measurement and testing device for the low-altitude wind tunnel spray and ice crystal system according to claim 2, characterized in that, A high-pressure gas regulating valve (10) is provided between the spray and ice crystal system (7) and the air intake switch valve (8).

4. The leakage rate measurement and testing device for the low-altitude wind tunnel spray and ice crystal system according to claim 3, characterized in that, A suction regulating valve (14) is provided between the wind tunnel body (1) and the vacuum system (13).

5. The leakage rate measurement and testing device for the low-altitude wind tunnel spray and ice crystal system according to claim 1, characterized in that, The first pressure transmitter (2) and the third temperature transmitter (9), the second pressure transmitter (3) and the second temperature transmitter (6), and the third pressure transmitter (4) and the first temperature transmitter (5) are respectively arranged opposite to each other.

6. The test method of the leakage rate measurement test device for the low-altitude wind tunnel spray and ice crystal system as described in claim 4, characterized in that, Specifically, the following steps are included: S1. Start the fan in the wind tunnel power section (12) to generate airflow in the wind tunnel body (1) and the wind tunnel test section (11). Then start the cooling system (15) to lower the airflow temperature in the wind tunnel. After the temperature stabilizes, measure the ambient temperature of the wind tunnel test section (11) through the first temperature transmitter (5), the second temperature transmitter (6), and the third temperature transmitter (9). The measured temperatures are T1, T2, and T3, respectively. Then the wind tunnel temperature T 风洞 =(T1+T2+T3) / 3;When conducting environmental tests in the wind tunnel, the values ​​measured in the wind tunnel test section (11) shall be taken as the standard; S2. Establishing a vacuum environment: The wind tunnel body (1) is evacuated using a vacuum system (13) and a vacuum regulating valve (14). According to the formula P=P0×(1-2.25577×10 -5 ×h) 5.25588 , where P0=101325Pa, P is the atmospheric pressure value at an altitude of h, and the target pressure P can be measured by the first pressure transmitter (2), the second pressure transmitter (3), and the third pressure transmitter (4); The values ​​measured by the first pressure transmitter (2), the second pressure transmitter (3), and the third pressure transmitter (4) are P1, P2, and P3 respectively. Then P = (P1 + P2 + P3) / 3. S3. Conduct a pressure test on the wind tunnel and simultaneously measure the air leakage at different altitudes in real time: First, measure the temperature and corresponding air density inside the wind tunnel at different altitudes in real time. The calculation process is shown below: r 空气 =1.293×(P / P0)×(273.15 / K 实际绝对 ) ①; K 实际绝对 =T 风洞 +273.15 ②; Where, ρ 空气 P is the air density, P is the atmospheric pressure at an altitude of h, P0 is the standard physical atmospheric pressure, and K is the atmospheric pressure. 实际绝对 This refers to the actual absolute temperature. The formula for calculating wind tunnel leakage is: △m 风洞 =(ρ2-ρ1)V 风洞容积 ③; Where ρ1 is the air density of the first sample, ρ2 is the air density of the second sample, and V 风洞容积 For the wind tunnel volume, Δm 风洞 The air leakage rate in real time for maintaining pressure in the wind tunnel; S4. Measure the leakage rate of the spray and ice crystal system (7): Repeat S3, turn on the spray and ice crystal system (7) while maintaining pressure, and adjust the air intake rate of the spray and ice crystal system (7) by opening the air intake switch valve (8) and the high pressure gas regulating valve (10). At this time, measure the amount of gas mixed into the spray and ice crystal system (7) in real time Δm. 混 The calculation method is the same as △m 风洞 The method is the same; S5. Calculate the leakage rate Δm of the spray and ice crystal system (7). 喷雾及冰晶 ; △m 喷雾及冰晶 =△m 混 -△m 风洞 ④。

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