A method for selecting the opening ratio test on the partition plate of an aircraft fuel tank

Abstract

The present application belongs to the technical field of aircraft fuel tank design, and specifically relates to a method for selecting an opening ratio test on a partition in an aircraft fuel tank, comprising: a step of determining a minimum opening ratio on the partition, wherein the minimum opening ratio on the partition is determined based on the fuel cross-contamination requirement of the fuel tank; a step of determining a maximum opening ratio on the partition, wherein the maximum opening ratio on the partition is determined based on the effect of the opening ratio on the weakening of the partition strength caused by fuel sloshing, so as to ensure the strength of the partition; a step of selecting an opening ratio test on the partition, wherein a fuel sloshing test is conducted with the minimum opening ratio and the maximum opening ratio on the partition as limits, the sloshing form of the fuel in the tank and the load generated at different opening ratios are analyzed, and the opening ratio on the partition is selected and determined with reference to the fact that the fuel sloshing in the tank is small and the load generated is evenly distributed.

Description

Technical Field

[0001] The present application belongs to the technical field of aircraft fuel tank design, and in particular relates to a method for selecting an opening ratio test on a partition in an aircraft fuel tank. Background Art

[0002] When an aircraft is flying, the fuel in the tank will slosh, generating load. A small opening ratio on the tank partition is beneficial to suppress fuel sloshing. However, the oil-bleeding function requirements and lightweight design requirements of the space between the partitions of the tank require that the opening ratio should be as large as possible.

[0003] Currently, when designing the opening ratio of the baffle in an aircraft fuel tank, the main consideration is the lightweight design requirements of the baffle. Some lightening holes are opened, and the design is rough. The safety benefits brought by suppressing fuel sloshing are rarely considered.

[0004] This application is proposed in view of the above-mentioned technical defects. Summary of the Invention

[0005] The purpose of this application is to provide a method for selecting the porosity test on a baffle in an aircraft fuel tank, so as to overcome or alleviate at least one of the known technical defects.

[0006] The technical solution of this application is:

[0007] A method for selecting an opening ratio test on a bulkhead of an aircraft fuel tank comprises:

[0008] The minimum opening ratio determination step on the partition is to determine the minimum opening ratio on the partition based on the oil cross-contamination requirement of the oil tank;

[0009] The maximum opening ratio on the partition is determined based on the effect of the opening ratio on the weakening of the partition caused by fuel sloshing, so as to ensure the strength of the partition.

[0010] The procedure for selecting the aperture ratio on the partition plate test is to conduct a fuel slosh test with the minimum and maximum aperture ratios of the partition plate as the limits. The slosh patterns of the fuel in the fuel tank and the resulting loads at different aperture ratios are analyzed. The aperture ratio on the partition plate is selected based on the minimum fuel slosh and uniform load distribution in the tank. The fuel slosh test is specifically as follows:

[0011] A scaled-down model of the fuel tank is made of a transparent material, the upper cover of the fuel tank can be opened, and the edges of both sides of each partition are inserted into the slots on the inner sides of a pair of opposite side walls of the scaled-down model of the fuel tank to achieve connection;

[0012] Arrange pressure measuring points on the side wall of the scaled model of the fuel tank, and arrange strain measuring points on the partition;

[0013] Arrange a shaking platform, the shaking platform including a table top;

[0014] Fix the scale model of the fuel tank to the table of the shaking platform and fill the scale model of the fuel tank with fuel;

[0015] Arrange the camera so that it faces the scaled-down model of the fuel tank;

[0016] The shaking platform is activated, and the scaled-down fuel tank model is shaken at different amplitudes and frequencies through the platform. The pressure on the sidewall of the scaled-down fuel tank model is measured through the pressure measuring points, and the strain of the partition in the scaled-down fuel tank model is measured through the strain measuring points. The load generated by the fuel sloshing is then determined, and the sloshing pattern of the fuel in the scaled-down fuel tank model is recorded and observed using a camera.

[0017] By replacing the partition in the scaled-down fuel tank model and varying the aperture ratio between the minimum and maximum aperture ratios, the load generated by fuel sloshing in the scaled-down fuel tank model at different aperture ratios, amplitudes, and frequencies was obtained. The sloshing pattern of the fuel in the scaled-down fuel tank model was also photographed and observed.

[0018] According to at least one embodiment of the present application, in the above-mentioned method for selecting the opening ratio test on the partition plate of the aircraft fuel tank, the shaking platform further includes a base frame and an actuator cylinder provided between the platform and the base frame;

[0019] Starting the shaking platform specifically involves starting the actuator in the shaking platform to drive the table top to shake.

[0020] According to at least one embodiment of the present application, in the above-mentioned method for selecting the opening rate test on the partition plate of the aircraft fuel tank, the number of actuators in the shaking platform is 6.

[0021] According to at least one embodiment of the present application, in the above-mentioned method for selecting the opening rate test on the partition of the aircraft fuel tank, in the fuel sloshing test, an angle sensor is set on the table top of the sloshing platform, and the angle sensor monitoring data is used to analyze the sloshing amplitude and frequency of the fuel tank scale model.

[0022] According to at least one embodiment of the present application, in the above-mentioned method for selecting the porosity test on the partition of an aircraft fuel tank, during the fuel slosh test, a monitor is connected to the pressure measuring points and the strain measuring points to monitor the load generated by the fuel slosh in the scaled model of the fuel tank.

[0023] According to at least one embodiment of the present application, in the above-mentioned method for selecting the porosity test on the partition of an aircraft fuel tank, during the fuel sloshing test, a monitor is connected to a camera to record and observe the sloshing pattern of the fuel in the scaled model of the fuel tank.

[0024] According to at least one embodiment of the present application, in the above-mentioned method for selecting the opening rate test on the partition of the aircraft fuel tank, in the fuel sloshing test, a monitor is connected to the six actuators in the sloshing platform, and an angle sensor is connected to constitute a negative feedback control of the sloshing amplitude and frequency of the fuel tank scale model.

[0025] According to at least one embodiment of the present application, in the above-mentioned method for selecting the porosity ratio of the aircraft fuel tank bulkhead, the fuel tank scale model used in the fuel slosh test is made of acrylic material.

[0026] According to at least one embodiment of the present application, in the above-mentioned method for selecting the porosity test on the partition of an aircraft fuel tank, in the fuel sloshing test, the lower bottom wall of the fuel tank scale model protrudes from the side wall and is fixed to the table surface of the sloshing platform with screws.

[0027] According to at least one embodiment of the present application, in the above-mentioned method for selecting the porosity test on the partition of an aircraft fuel tank, in the fuel slosh test, a plurality of angular support plates are provided between the lower bottom wall and the outer side of the side wall of the fuel tank scale model for support. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of a method for selecting an opening ratio test on a baffle in an aircraft fuel tank provided in an embodiment of the present application;

[0029] Figure 2 is a schematic diagram of a scaled-down model of a fuel tank provided in an embodiment of the present application;

[0030] Figure 3 Schematic diagram of a shaking platform provided in an embodiment of the present application;

[0031] Figure 4 Schematic diagram of separators with different opening rates provided in the embodiments of the present application;

[0032] in:

[0033] 1- scale model of the fuel tank; 2- partition; 3- rocking platform; 4- base frame; 5- table; 6- actuator; 7- angle sensor; 8- angular support plate.

[0034] In order to better illustrate this embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. In addition, the drawings are only used for illustrative purposes and should not be understood as limiting this application. DETAILED DESCRIPTION

[0035] To make the technical solution and its advantages of this application more clear, the technical solution of this application will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described here are only some of the embodiments of this application and are only used to explain this application, not to limit this application. It should be noted that for ease of description, only the parts relevant to this application are shown in the accompanying drawings, and other relevant parts can refer to the general design.

[0036] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of this application should have the usual meanings understood by those skilled in the art in the field to which this application belongs. The words indicating orientation used in the description of this application are only used to indicate relative directions or positional relationships. When the absolute position of the described object changes, its relative positional relationship may also change accordingly. The word "include" used in the description of this application means that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, but does not exclude other elements or objects.

[0037] In addition, it should be noted that, unless otherwise clearly stipulated and limited, the words "installation", "connection" and similar terms used in the description of this application should be understood in a broad sense. For example, the connection can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Technical personnel in the field can understand its specific meaning in this application according to the specific circumstances.

[0038] A method for selecting the opening ratio test on the partition plate of an aircraft fuel tank, such as Figure 1 As shown, it includes the steps of determining the minimum opening ratio on the partition, determining the maximum opening ratio on the partition, and selecting the opening ratio test on the partition.

[0039] Steps to determine the minimum opening ratio on the partition:

[0040] Based on the oil flow requirement of the oil tank, that is, the requirement for the connectivity of the oil tank, the minimum opening rate on the partition is determined. Specifically, the minimum opening area on the partition is determined according to the oil supply demand of the oil tank, and then the minimum opening rate is obtained by dividing the minimum opening area by the total area of ​​the partition. In a typical example, the total area of ​​the partition is 1000mm2, and the minimum opening area is 50mm2, resulting in a minimum opening rate of 5%. This value can be used as an empirical value.

[0041] Steps to determine the maximum opening ratio on the partition:

[0042] Based on the effect of the opening ratio on the weakening of the partition caused by fuel sloshing, the maximum opening ratio of the partition is determined to ensure the strength of the partition. The specific process can be referred to as follows:

[0043] Determining changes in the attitude of the oil level in the fuel tank, including changes in the oil level pitch angle and the oil level roll angle. In a specific example, determining that the maximum oil level pitch angle is ±40°, the maximum oil level roll angle is 60°, the oil level attitude changes within the range of the maximum oil level pitch angle and the maximum oil level roll angle, and the rate of change of the oil level pitch angle and the oil level roll angle is 0.5° to 5° per second;

[0044] Based on the aircraft's operating requirements and the changes in the oil level in the fuel tank, the maximum opening area is determined, with the impact of the opening area on the weakening of the baffle caused by fuel sloshing as a constraint. The maximum opening ratio is then calculated by dividing the maximum opening area by the total area of ​​the baffle. In a typical example, the total area of ​​the baffle is 1000mm2, the maximum opening area is 300mm2, and the minimum opening ratio is 30%, which can be used as an empirical value.

[0045] Steps for selecting the opening ratio test on the partition:

[0046] The fuel slosh test is conducted with the minimum and maximum opening ratios on the partition plate as the limits. The slosh patterns of the fuel in the tank and the resulting loads at different opening ratios are analyzed. The opening ratio on the partition plate is selected based on the conditions where the fuel slosh in the tank is small and the resulting load is evenly distributed. Due to the relatively weak strength of the partition plate, the magnitude and uniformity of the load on the partition plate can be given priority when determining the opening ratio. The fuel slosh in the tank and the magnitude and uniformity of the load on the sidewalls are also considered comprehensively. The fuel slosh test can be specifically referred to as follows:

[0047] Make a scale model of the fuel tank 1. The scale model of the fuel tank 1 is made of transparent material. The upper cover can be opened, and the edges of both sides of each partition 2 are inserted into the grooves on the inner side of a pair of opposite side walls of the scale model of the fuel tank 1 to achieve connection. Figure 2 As shown;

[0048] Arrange pressure measuring points on the side wall of the scaled model 1 of the fuel tank, and arrange strain measuring points on the partition 2;

[0049] Arrange a shaking platform 3, which includes a base frame 4, a table 5, and six actuators 6 connected between the base frame 4 and the table 5. Figure 3 As shown;

[0050] Fix the fuel tank scale model 1 to the table 5 of the shaking platform 3, and fill the fuel tank scale model 1 with fuel;

[0051] Arrange the camera so that it faces the fuel tank scale model 1;

[0052] The six actuators 6 in the shaking platform 3 are activated, causing the scaled-down fuel tank model 1 to shake at different amplitudes and frequencies via the table 5. The pressure on the sidewall of the scaled-down fuel tank model 1 is measured using the pressure measuring points, and the strain of the partition 2 in the scaled-down fuel tank model 1 is measured using the strain measuring points. The load generated by the fuel sloshing is then determined, and the sloshing pattern of the fuel in the scaled-down fuel tank model 1 is recorded and observed using a camera.

[0053] Replace the partition 2 in the fuel tank scale model 1, and change the opening ratio on the partition 2 within the range of minimum opening ratio and maximum opening ratio. Obtain the load caused by the fuel sloshing in the fuel tank scale model 1 under different opening ratios, various amplitudes, and frequencies of sloshing. The sloshing pattern of the fuel in the fuel tank scale model 1 is also photographed and observed.

[0054] In a typical example, there are three types of designed partitions, with opening rates of 5%, 10%, and 20% respectively. Figure 4 As shown, a fuel sloshing test was conducted. It was analyzed that when the opening ratio was 10%, the fuel sloshing was small, and the load generated on the partition and its side wall was small and distributed more evenly. It was determined that the opening ratio on the partition was 10%.

[0055] In the method for selecting the opening rate test on the partition in the aircraft fuel tank disclosed in the above embodiment, a fuel sloshing test is conducted on the basis of determining the minimum opening rate and the maximum opening rate on the partition, and the sloshing pattern of the fuel in the tank and the load generated at different opening rates are analyzed. The opening rate on the partition is selected and determined with reference to the small fuel sloshing in the tank and the uniform load distribution generated, and the oil mixing function requirements and lightweight design requirements of the space between the partitions of the tank are comprehensively considered, and the safety benefits brought by suppressing fuel sloshing are considered.

[0056] The above-mentioned embodiment discloses a method for selecting the aperture ratio test of the partition in the aircraft fuel tank. A fuel tank scale model 1 is designed to replace the actual fuel tank for the fuel sloshing test. The cover above the fuel tank scale model 1 is designed to be open, and the edges on both sides of each partition 2 are inserted into the slots on the inner sides of a pair of opposite side walls of the fuel tank scale model 1. In this way, the partition 2 can be easily replaced, and the aperture ratio can be easily changed. The fuel tank scale model 1 is designed to be made of transparent material, so that the fuel sloshing shape can be easily observed. In addition, the sloshing platform 3 is designed to be a six-degree-of-freedom sloshing platform, so that the required sloshing can be easily generated.

[0057] In some optional embodiments, in the above-mentioned method for selecting the opening rate test on the partition of the aircraft fuel tank, an angle sensor 7 is set on the table 5 of the shaking platform 3, and the angle sensor 7 monitors the data to analyze the shaking amplitude and frequency of the fuel tank scale model 1.

[0058] In some optional embodiments, in the above-mentioned method for selecting the porosity test on the bulkhead of an aircraft fuel tank, a monitor is connected to the pressure measuring point and the strain measuring point to monitor the load generated by the fuel sloshing in the fuel tank scale model 1;

[0059] Connect a camera to the monitor to record and observe the sloshing pattern of the fuel in the scaled fuel tank model 1;

[0060] The monitor is connected to the six actuators 6 in the shaking platform 3 and the angle sensor 7 to form a negative feedback control of the shaking amplitude and frequency of the oil tank scale model 1.

[0061] In some optional embodiments, in the above-mentioned method for selecting the opening ratio test on the partition of the aircraft fuel tank, the fuel tank scale model 1 is made of acrylic material, and can also be made of other transparent plastics with stable properties.

[0062] In some optional embodiments, in the above-mentioned method for selecting the opening rate test on the partition of the aircraft fuel tank, the lower bottom wall of the fuel tank scale model 1 protrudes from the side wall and is fixed to the table 5 of the shaking platform 3 with screws.

[0063] In some optional embodiments, in the above-mentioned method for selecting the opening rate test on the partition of the aircraft fuel tank, a plurality of angular support plates 8 are provided between the lower bottom wall and the outer side of the side wall of the fuel tank scale model 1 for support.

[0064] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other. In the absence of conflict, the embodiments in this application and the technical features in the embodiments can be combined with each other to obtain new embodiments.

[0065] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art can make equivalent changes or replacements to the relevant technical features, and the technical solutions after these changes or replacements will fall within the scope of protection of the present application.

Claims

1. A method for selecting the opening ratio of the partition plate in an aircraft fuel tank, characterized in that: include: The minimum opening ratio determination step on the partition is to determine the minimum opening ratio on the partition based on the oil cross-contamination requirement of the oil tank; The maximum opening ratio on the partition is determined based on the effect of the opening ratio on the weakening of the partition caused by fuel sloshing, so as to ensure the strength of the partition. The procedure for selecting the aperture ratio on the partition plate test is to conduct a fuel slosh test with the minimum and maximum aperture ratios of the partition plate as the limits. The slosh patterns of the fuel in the fuel tank and the resulting loads at different aperture ratios are analyzed. The aperture ratio on the partition plate is selected based on the minimum fuel slosh and uniform load distribution in the tank. The fuel slosh test is specifically as follows: A scaled-down model of a fuel tank (1) is made of a transparent material, the upper cover of the fuel tank (1) can be opened, and the edges of both sides of each partition (2) are inserted into the slots on the inner sides of a pair of opposite side walls of the scaled-down model of the fuel tank (1) to achieve connection; Arranging pressure measuring points on the side wall of the scaled model (1) of the oil tank, and arranging strain measuring points on the partition (2); Arranging a shaking platform (3), wherein the shaking platform (3) includes a table (5); Fixing the scaled-down model of the fuel tank (1) to the tabletop (5) of the shaking platform (3), and filling the scaled-down model of the fuel tank (1) with fuel; Arrange a camera so that the camera faces the scaled-down model of the fuel tank (1); The shaking platform (3) is started, and the oil tank scale model (1) is driven to shake at different amplitudes and frequencies through the table (5), and the pressure on the side wall of the oil tank scale model (1) is measured through the pressure measuring point, and the strain of the partition (2) in the oil tank scale model (1) is measured through the strain measuring point, thereby obtaining the load generated by the oil shaking, and the shaking shape of the oil in the oil tank scale model (1) is filmed and observed through a camera; The partition (2) in the scaled-down fuel tank model (1) is replaced, and the aperture ratio of the partition (2) is changed within the range of minimum aperture ratio and maximum aperture ratio, so as to obtain the load generated by the fuel sloshing in the scaled-down fuel tank model (1) under different aperture ratios, various amplitudes, and frequencies of sloshing, and to photograph and observe the sloshing form of the fuel in the scaled-down fuel tank model (1).

2. The method for selecting the opening ratio of the partition plate in the aircraft fuel tank according to claim 1 is characterized in that: The shaking platform (3) further comprises a base frame (4) and an actuating cylinder (6) arranged between the table top (5) and the base frame (4); Starting the shaking platform (3) specifically involves starting the actuator (6) in the shaking platform (3) to drive the table (4) to shake.

3. The method for selecting the opening ratio of the partition plate in the aircraft fuel tank according to claim 2 is characterized in that: The number of the actuators (6) in the shaking platform (3) is 6.

4. The method for selecting the opening ratio of the partition plate in the aircraft fuel tank according to claim 3 is characterized in that: In a fuel sloshing test, an angle sensor (7) is provided on a middle table (5) of a sloshing platform (3), and the sloshing amplitude and frequency of a scaled-down fuel tank model (1) are analyzed using monitoring data from the angle sensor (7).

5. The method for selecting the opening ratio of the partition plate in the aircraft fuel tank according to claim 4 is characterized in that: In the fuel sloshing test, a monitor is connected to the pressure measuring points and the strain measuring points to monitor the load generated by the fuel sloshing in the scale model (1) of the fuel tank.

6. The method for selecting the opening ratio of the partition plate in the aircraft fuel tank according to claim 5, characterized in that: In the fuel sloshing test, a monitor is connected to a camera to record and observe the sloshing pattern of the fuel in the scale model (1) of the fuel tank.

7. The method for selecting the opening ratio of the partition plate in the aircraft fuel tank according to claim 6 is characterized in that: In the fuel sloshing test, a monitor is connected to six actuators (6) in a sloshing platform (3) and an angle sensor (7) to form a negative feedback control of the sloshing amplitude and frequency of a scaled model of a fuel tank (1).

8. The method for selecting the opening ratio of the partition plate in the aircraft fuel tank according to claim 7, characterized in that: In the fuel sloshing test, the scale model (1) of the fuel tank is made of acrylic material.

9. The method for selecting the opening ratio of the partition plate in the aircraft fuel tank according to claim 8, characterized in that: In the fuel sloshing test, the lower bottom wall of the fuel tank scale model (1) protrudes from the side wall and is fixed to the table (5) of the sloshing platform (3) with screws.

10. The method for selecting the opening ratio of the partition plate in the aircraft fuel tank according to claim 9, characterized in that: In the fuel sloshing test, a plurality of angular support plates (8) are provided between the lower bottom wall and the outer side of the side wall of the fuel tank scale model (1) for support.

Images