Combustion observation system of nano-aluminized fuel film and application thereof

Abstract

The application discloses a kind of nanometer thermite film combustion observation system and its application, it is related to combustion observation platform technical field, including high-speed camera, lens, macro-burning rate observation platform and cross-gap propagation observation platform, macro-burning rate observation platform includes slide holder, slide holder is provided with slide slot, cross-gap propagation observation platform includes guide rail base and the fixed angle platform, adjustable angle platform of being set on guide rail base, guide rail base is horizontally arranged, lens is vertically oriented the gap between fixed angle platform and adjustable angle platform, nanometer thermite film slide is carried on fixed angle platform and adjustable angle platform.The application adopts the structure and step of above-mentioned one kind of nanometer thermite film combustion observation system and its application, the combustion event of micron level nanometer thermite film is recorded, realizes the research demand of thin film combustion cross-gap propagation ability under different distances, different included angle.

Description

Technical Field

[0001] The present invention relates to the technical field of combustion observation platforms, in particular to a combustion observation system of a nano-thermite film. Background Art

[0002] Existing methods for preparing nanothermite films include magnetron sputtering, electrophoretic deposition, and ink coating. Magnetron sputtering is expensive, and electrophoretic deposition is a complex process. However, coating with thermite ink is inexpensive and simple. Cracks in nanothermite films can affect combustion propagation to varying degrees. However, studying the combustion process at these cracks is hampered by the rapid burning rate of thermite, the large amount of flame and sputtering products involved in the combustion process, and the fact that the combustion process occurs at the micrometer level, making observation and research difficult. Summary of the Invention

[0003] The purpose of the present invention is to provide a combustion observation system for nano-thermite films and its application. By combining a high-speed camera with a lens, the combustion events of nano-thermite films at the micron level are recorded, thereby meeting the research needs on the cross-gap propagation capability of film combustion at different distances and angles.

[0004] To achieve the above-mentioned objectives, the present invention provides a combustion observation system for a nano-thermite film, comprising a high-speed camera, a lens, a macroscopic burning rate observation platform, and a cross-gap propagation observation platform. The macroscopic burning rate observation platform comprises a glass slide clamp, the glass slide clamp is provided with a glass slide slot, and compression adjustment knobs are respectively provided on both sides of the front end of the glass slide clamp. The cross-gap propagation observation platform comprises a guide rail base and a fixed angle platform and an adjustable angle platform arranged on the guide rail base. The nano-thermite film glass slide is mounted on the fixed angle platform and the adjustable angle platform.

[0005] Preferably, the fixed angle platform includes a slider, a fixed pad, and a glass cover. The slider is arranged on the guide rail base, a slider displacement adjustment knob is provided on the side of the slider, the fixed pad is arranged on the slider, the nano-thermite film glass slide is fixed to the fixed pad by a clamp, a glass cover is provided above the fixed pad, and the nano-thermite film glass slide is located in the gap between the glass cover and the fixed pad.

[0006] Preferably, the adjustable angle platform includes a slider, an adjustable pad, and an angle adjustment knob. The slider is arranged on the guide rail base, a slider displacement adjustment knob is arranged on the side of the slider, the adjustable pad is arranged on the slider, and the angle adjustment knob is arranged on the side of the adjustable pad.

[0007] The application of a nano-thermite film combustion observation system, including macroscopic burning rate test and cross-gap combustion propagation test,

[0008] Macroscopic burning rate test: Fix the prepared nanothermite film slide in the slide slot on the macroscopic burning rate observation platform, ignite the nanothermite film, conduct a macroscopic burning rate test, and calculate the macroscopic burning rate propagation rate;

[0009] Cross-gap combustion propagation test: The prepared nano-thermite film glass slides were placed on a fixed-angle platform and an adjustable-angle platform respectively, and the nano-thermite film was ignited. By setting the distance between the two films, the combustion propagation ability of the film under different gap widths was measured. By changing the angle between the two films, the effect of the angle on the cross-gap propagation between the films was tested. A high-speed camera was used to capture the particles sputtered by the film's combustion and measure their size and speed.

[0010] Preferably, the steps of preparing the nano-thermite film slide are as follows:

[0011] S1.1. Preparation of nano-thermite ink: First, a thickener and a binder are dissolved in an N,N-dimethylformamide solution, and then Al and a metal oxide are added to the solution. The thermite is uniformly mixed by magnetic stirring and mechanical stirring to prepare the thermite ink.

[0012] S1.2. Preparation of nano-thermite film glass slide: Place the glass slide on a heating platform at 80°C. Put thermite ink into a syringe and drop it on the glass slide. Use an applicator to evenly cover the thermite ink. After the thermite ink dries, add more thermite ink, apply and dry. Repeat this process three times to obtain a nano-thermite film of a specific thickness.

[0013] Preferably, the specific steps for performing the macro burning rate test are as follows:

[0014] S2.1. Direct the high-speed camera and lens toward the uncoated side of the nanothermite film slide. Adjust the zoom ring to focus the camera on the nanothermite film surface. Ignite the nanothermite film with a nickel-chromium resistance wire and begin recording a video of the combustion propagation.

[0015] S2.2. After shooting a set of combustion propagation videos, use video software to edit them. Calibrate a known distance in the video as a reference to obtain the actual length of each pixel.

[0016] S2.3. Select a point on the bright reaction front as the initial value, play the video, and after the reaction front propagates a certain distance, select another point on the reaction front corresponding to the same axis. Calculate the macroscopic burning rate propagation rate based on the number of pixels between the two points. The calculation formula is as follows:

[0017]

[0018] Where n is the number of pixels in the interval, t is the time, and a is the actual length corresponding to each pixel, in mm / pixel.

[0019] Preferably, the specific steps of performing the cross-gap combustion propagation test are as follows:

[0020] S3.1. Assemble two glass slides with nanothermite films, designated slide A and slide B. Secure slide A to the fixed pad of a fixed-angle platform, and slide B to the adjustable pad of an adjustable-angle platform. Use the fixed and adjustable pads to maintain slides A and B at the same height.

[0021] S3.2. Set the high-speed camera to low-light mode and illuminate the gaps in the film with a light source, allowing light to pass through the gaps and enter the lens. Adjust the zoom ring to focus the camera on the edge of the nanothermite film and set appropriate high-speed camera parameters.

[0022] S3.3. Use the slider adjustment knob to set the gap between the two films with an adjustment accuracy of 1 μm. Ignite the nanothermite film, turn off low-light mode, and begin recording a combustion video. Measure the combustion propagation capability of the films at different gap widths. Calculate the sputtering rate of the sputtered particles based on the combustion video.

[0023] S3.4. Turn the angle adjustment knob to set slide B to different set angles (0°, 30°, 60°, and 90°). Ignite the nanothermite film at each angle. Turn off low-light mode and start recording the combustion video to test the effect of angle on propagation across the gap between films.

[0024] S3.5. In the combustion video, capture a frame with clear light spots of the sputtering particles. On the same frame, select two points with different diameters of the sputtering particles. Calculate the size of the sputtering particles based on the number of pixels between the two points.

[0025] Therefore, the present invention adopts a nano-thermite film combustion observation system and its application with the above-mentioned structure and steps, uses an observation platform with adjustable spacing and angle to adjust the condition parameters during the combustion and propagation process of the nano-thermite film, captures the combustion propagation and cross-gap combustion process based on a high-speed camera and lens, and performs accurate combustion rate calculations, which helps promote the research on the mechanism of combustion propagation.

[0026] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of a process for preparing nano-thermite ink according to Example 1 of a combustion observation system for a nano-thermite film of the present invention;

[0028] Figure 2 Schematic diagram of the structure of a cross-gap propagation observation platform according to embodiment 2 of the present invention;

[0029] Figure 3 This is a schematic structural diagram of a macroscopic burning rate observation platform according to Example 1 of the present invention;

[0030] Figure 4 This is a picture of the reaction front propagation process in the macroscopic burning rate test of Example 1 of the present invention;

[0031] Figure 5 This is a picture of particle sputtering in the cross-gap propagation test of Example 2 of the present invention.

[0032] Reference numerals

[0033] 1. High-speed camera; 2. Lens; 3. Guide rail base; 4. Fixed-angle platform; 5. Adjustable-angle platform; 6. Slider; 7. Slider displacement adjustment knob; 8. Fixed pad; 9. Nano-thermite film slide; 10. Glass cover; 11. Adjustable pad; 12. Angle adjustment knob; 13. Slide clamp; 14. Slide slot; 15. Compression adjustment knob. DETAILED DESCRIPTION

[0034] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0035] Example 1

[0036] A combustion observation system for a nano-thermite film includes a high-speed camera 1 (Phantom VEO710L), a lens 2, a macroscopic burning rate observation platform, and a cross-gap propagation observation platform.

[0037] The application of the combustion observation system based on the nano-thermite film mentioned above includes macroscopic burning rate test and cross-gap combustion propagation test. Before the test, it is necessary to prepare the nano-thermite film glass slide 9, and the steps are as follows:

[0038] S1.1, Preparation of nano-thermite ink: First, dissolve a thickener (such as polyvinylidene fluoride, PVDF) and a binder (such as hydroxypropyl methylcellulose, HPMC) in N,N-dimethylformamide (DMF) solution, then add Al and metal oxide (such as copper oxide, CuO) to the above solution, and perform magnetic stirring and mechanical stirring to uniformly mix the thermite to prepare the thermite ink. The process is as follows Figure 1 shown.

[0039] S1.2. Preparation of nano-thermite thin film glass slide 9: Place the glass slide on a heating platform at 80°C. Put thermite ink into a syringe and drop it on the glass slide. Use an applicator to evenly cover the thermite ink. After the thermite ink dries, add more thermite ink, apply and dry. Repeat this process three times to obtain a nano-thermite film of a specific thickness.

[0040] On the basis of the prepared nano-thermite film glass slide 9, a macroscopic burning rate test was conducted through a macroscopic burning rate observation platform. When conducting the macroscopic burning rate test, a Tokina lens was used.

[0041] like Figure 3 As shown, the macroscopic burning rate observation platform includes a slide holder 13, which is provided with a slide slot 14. Two front ends of the slide holder 13 are provided with compression adjustment knobs 15 for clamping the nanothermite film slide 9 placed in the slide slot 14. The macroscopic burning rate observation platform is used to observe the state of the uninterrupted combustion of the nanothermite film.

[0042] The specific steps for conducting a macro burning rate test are as follows:

[0043] S2.1. Direct high-speed camera 1 and lens 2 toward the uncoated surface of nanothermite film slide 9. Adjust the zoom ring to focus camera 1 on the surface of the nanothermite film. Set the aperture to f / 2.8 and the camera to focus on the surface of the nanothermite film. Set the camera exposure time to 5 μs, the sampling rate to 18,000 fps, and the resolution to 512 × 512 pixels. Ignite the nanothermite film with a nickel-chromium resistance wire at a current of 4 A, and begin recording a video of the combustion propagation.

[0044] S2.2. After shooting a set of combustion propagation videos, use PCC software to edit them. Calibrate a known distance in the video as a reference to obtain the actual length of each pixel.

[0045] S2.3. Select a point on the bright reaction front as the initial value, play the video, and after the reaction front propagates a certain distance, select another point on the reaction front corresponding to the same axis. Calculate the macroscopic burning rate propagation rate based on the number of pixels between the two points. The calculation formula is as follows:

[0046]

[0047] Where n is the number of pixels in the interval, t is the time, and a is the actual length corresponding to each pixel, in units of mm / pixel. Figure 4 (a) and (b) correspond to the positions of the reaction front at different times, respectively. The combustion propagates upward, and the calculated propagation rate is 19 mm / s.

[0048] Example 2

[0049] The difference between this embodiment and embodiment 1 is that the cross-gap propagation test is performed through a cross-gap propagation observation platform.

[0050] like Figure 2 As shown, the fixed-angle platform 4 includes a slider 6, a fixed pad 8, and a glass cover 10. The slider 6 is mounted on the guide rail base 3. A slider displacement adjustment knob 7 is provided on the side of the slider 6, which can be used to adjust the position of the slider 6 on the guide rail base 3. The fixed pad 8 is mounted on the slider 6, and a nanothermite film glass slide 9 is fixed to the fixed pad 8 via a clamp. The angle of the fixed pad 8 cannot be adjusted. A glass cover 10 spans above the fixed pad 8. The nanothermite film glass slide 9 is located in the gap between the glass cover 10 and the fixed pad 8. The glass cover 10 is located at the end of the fixed-angle platform 4 near the adjustable-angle platform 5. The glass cover 10 semi-encloses the combustion transmission end of the nanothermite film glass slide 9, forcing the flame to propagate only from the side toward the adjustable-angle platform 5, while also preventing the flame from rising and damaging the lens.

[0051] The adjustable angle platform 5 includes a slider 6, an adjustable pad 11, and an angle adjustment knob 12. The slider 6 is arranged on the guide rail base 3. The slider displacement adjustment knob 7 is arranged on the side of the slider 6. The adjustable pad 11 is arranged on the slider 6. The angle adjustment knob 12 is arranged on the side of the adjustable pad 11. By rotating the angle adjustment knob 12, the rotation angle of the adjustable pad 11 can be changed, thereby changing the angle between the glass slide on the adjustable pad 11 and the glass slide on the fixed pad 8.

[0052] The specific steps for conducting a cross-gap combustion propagation test are as follows:

[0053] S3.1. Let two glass slides with nano-thermite films be glass slide A and glass slide B, respectively. The thickness of the nano-thermite films is 500 μm. Fix glass slide A on the fixed pad 8 of the fixed angle platform 4, and fix glass slide B on the adjustable pad 11 of the adjustable angle platform 5. Use the fixed pad 8 and the adjustable pad 11 to keep glass slide A and glass slide B at the same height.

[0054] S3.2. Use a K2 DistaMax lens with a CF-4 objective lens and an NTX tube at maximum aperture. Set high-speed camera 1 to low-light mode and illuminate the gap in the film with a light source, allowing light to pass through the gap and enter the lens. Adjust the zoom ring to focus high-speed camera 1 on the edge of the nanothermite film. The lens working distance is approximately 5.4 mm, the camera exposure time is 390 μs, the sampling rate is 2500 fps, and the captured image is 512 × 512 pixels with a resolution of approximately 1.7 μm / pixel.

[0055] S3.3. Use the slider displacement adjustment knob 7 to set the spacing between the two films with an adjustment accuracy of 1 μm. Ignite the nanothermite film, turn off the low-light mode and take photos. Measure the combustion propagation ability of the film under different gap widths. The speed measurement method used is the same as the macroscopic burning rate process. The calculated particle sputtering rate is 1.3 m / s.

[0056] S3.4. Turn the angle adjustment knob 12 to adjust slide B to different set angles (0°, 30°, 60°, and 90°). Ignite the nanothermite film at each angle to test the effect of angle on the propagation of particles across the gap between films. As the angle increases, the area of ​​slide B receiving the sputtered particles from slide A increases, resulting in a faster combustion propagation rate.

[0057] S3.5. In the combustion video, capture a frame with a clear light spot of the sputtering particles. On the same frame, select two points with different diameters of the sputtering particles. Calculate the size of the sputtering particles based on the number of pixels between the two points. Figure 5 As shown, (a), (b), (c), and (d) are particle sputtering images taken at different times, and the particle size can be measured to be about 64 μm (half of the light spot diameter is taken as the particle diameter).

[0058] Therefore, the present invention adopts a nano-thermite film combustion observation system and its application with the above-mentioned structure and steps, uses an observation platform with adjustable spacing and angle to adjust the condition parameters during the combustion and propagation process of the nano-thermite film, captures the combustion propagation and cross-gap combustion process based on a high-speed camera and lens 2, and performs accurate combustion rate calculations, which helps promote the research on the mechanism of combustion propagation.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An application of a combustion observation system for a nano-thermite film, characterized in that: The combustion observation system includes a high-speed camera, a lens, a macroscopic burning rate observation platform, and a cross-gap propagation observation platform. The macroscopic burning rate observation platform includes a glass slide fixture, which is provided with a glass slide slot. The front ends of the glass slide fixture are respectively provided with compression adjustment knobs. The cross-gap propagation observation platform includes a guide rail base and a fixed angle platform and an adjustable angle platform provided on the guide rail base. The guide rail base is arranged horizontally, and the lens is vertically facing the gap between the fixed angle platform and the adjustable angle platform. The nano-thermite film glass slide is mounted on the fixed angle platform and the adjustable angle platform. Applications of combustion observation systems include macroscopic burning rate testing and cross-gap combustion propagation testing. Macroscopic burning rate test: Fix the prepared nanothermite film slide in the slide slot on the macroscopic burning rate observation platform, ignite the nanothermite film, conduct a macroscopic burning rate test, and calculate the macroscopic burning rate propagation rate; The specific steps for conducting a macro burning rate test are as follows: S2.

1. Direct the high-speed camera and lens toward the uncoated side of the nanothermite film slide. Adjust the zoom ring to focus the camera on the nanothermite film surface. Ignite the nanothermite film with a nickel-chromium resistance wire and begin recording a video of the combustion propagation. S2.

2. After shooting a set of combustion propagation videos, use video software to edit them. Calibrate a known distance in the video as a reference to obtain the actual length of each pixel. S2.

3. Select a point on the bright reaction front as the initial value, play the video, and after the reaction front propagates a certain distance, select another point on the reaction front corresponding to the same axis. Calculate the macroscopic burning rate propagation rate based on the number of pixels between the two points. The calculation formula is as follows: Where n is the number of pixels in the interval, t is the time, and a is the actual length corresponding to each pixel, in mm / pixel; Cross-gap combustion propagation test: The prepared nanothermite film slides were placed on a fixed-angle platform and an adjustable-angle platform, respectively. The nanothermite film was ignited, and the spacing between the two films was set to measure the combustion propagation ability of the film under different gap widths. By changing the angle between the two films, the effect of the angle on the cross-gap propagation between the films was tested. A high-speed camera was used to capture the particles sputtered by the film combustion and measure their size and velocity. The specific steps for conducting a cross-gap combustion propagation test are as follows: S3.

1. Assemble two glass slides with nanothermite films, designated slide A and slide B. Secure slide A to the fixed pad of a fixed-angle platform, and slide B to the adjustable pad of an adjustable-angle platform. Use the fixed and adjustable pads to maintain slides A and B at the same height. S3.

2. Set the high-speed camera to low-light mode. Use a light source to illuminate the gaps in the film, allowing light to pass through the gaps and enter the lens. Adjust the zoom ring to focus the camera on the edge of the nanothermite film. Set appropriate high-speed camera parameters. S3.

3. Use the slider adjustment knob to set the gap between the two films with an adjustment accuracy of 1 μm. Ignite the nanothermite film, turn off low-light mode, and begin recording a combustion video. Measure the combustion propagation capability of the films at different gap widths. Calculate the sputtering rate of the sputtered particles based on the combustion video. S3.

4. Turn the angle adjustment knob to set slide B at different set angles (0°, 30°, 60°, and 90°). Ignite the nanothermite film at each of these angles. Turn off low-light mode and begin recording combustion videos to test the effect of angle on propagation across the gap between films. S3.

5. In the combustion video, capture a frame with clear light spots of the sputtering particles. On the same frame, select two points with different diameters of the sputtering particles. Calculate the size of the sputtering particles based on the number of pixels between the two points.

2. The use of a nano-thermite film combustion observation system according to claim 1, characterized in that: The fixed angle platform includes a slider, a fixed pad, and a glass cover. The slider is arranged on the guide rail base. A slider displacement adjustment knob is arranged on the side of the slider. The fixed pad is arranged on the slider. The nano-thermite film glass slide is fixed on the fixed pad by a clamp. A glass cover is arranged above the fixed pad. The nano-thermite film glass slide is located in the gap between the glass cover and the fixed pad.

3. The use of a nano-thermite film combustion observation system according to claim 1, characterized in that: The adjustable angle platform includes a slider, an adjustable pad, and an angle adjustment knob. The slider is set on the guide rail base, and a slider displacement adjustment knob is set on the side of the slider. The adjustable pad is set on the slider, and the angle adjustment knob is set on the side of the adjustable pad.

4. The use of a nano-thermite film combustion observation system according to claim 1, characterized in that: The steps for preparing nano-thermite film slides are as follows: S1.

1. Preparation of nano-thermite ink: First, a thickener and a binder are dissolved in an N,N-dimethylformamide solution, and then Al and a metal oxide are added to the solution. The thermite is uniformly mixed by magnetic stirring and mechanical stirring to prepare the thermite ink. S1.

2. Preparation of nano-thermite film glass slide: Place the glass slide on a heating platform at 80°C. Put thermite ink into a syringe and drop it on the glass slide. Use an applicator to evenly cover the thermite ink. After the thermite ink dries, add more thermite ink, apply and dry. Repeat this process three times to obtain a nano-thermite film of a specific thickness.

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