Aluminum-containing solid fuel diffusion combustion characteristic test device and test system

Abstract

This application provides a testing device and system for testing the diffusion combustion characteristics of aluminum-containing solid fuel. The device includes an oxidizer supply unit, an ignition unit, and a reaction unit. The oxidizer supply unit stores oxidizer. The ignition unit has a laser emitting section and an angle adjustment section, the angle adjustment section being used to adjust the laser emission angle. The reaction unit has a covering section, a rectifying section, and aluminum solid fuel disposed in the rectifying section. The rectifying section is connected to the oxidizer supply unit, and the covering section is used to cover the aluminum solid fuel in the rectifying section. The observation unit can record the combustion process of the aluminum solid fuel. Through the coordinated design of the oxidizer supply unit, ignition unit, reaction unit, and observation unit, a testing device capable of simulating the diffusion combustion flow field environment of a solid-liquid rocket engine is constructed. The ignition unit is a combination of a carbon dioxide laser and a corner mirror, achieving non-contact precise ignition and avoiding interference with the flow field.

Description

Technical Field

[0001] This application relates to the field of aerospace technology, and in particular to a testing device and system for testing the diffusion combustion characteristics of aluminum-containing solid fuels. Background Technology

[0002] In the research of rocket engines or solid propulsion technology, visual combustion testing devices are commonly used to test the ignition and combustion performance of solid fuels. Taking a testing device disclosed in existing technology (refer to patent CN104596768 B) as an example, this device mainly consists of a laser, a pressure-resistant glass-enclosed reactor, a vacuum pump, and an external observation and acquisition system. Specifically, a fixed platform is set up inside the reactor to mount a solid fuel micro-thruster. The laser is positioned above the glass enclosure; the laser beam, after being reflected by a 45-degree reflector, ignites the solid fuel non-contactly through an opening at the top. The reactor base has a gas path connecting to the vacuum pump for regulating the internal pressure environment. During testing, a computer controls the laser, high-speed camera, high-speed thermometer, and fiber optic spectrometer to start synchronously via a synchronous trigger switch. This allows for real-time monitoring of the solid fuel combustion process and flame morphology, converting the collected analog quantities such as temperature, thrust, and specific impulse into digital signals and transmitting them to the computer. This enables the synchronous recording and analysis of macroscopic performance data such as ignition delay, combustion flame morphology, and thrust curves.

[0003] The existing structures described above cannot simulate the diffusion combustion flow field environment unique to solid-liquid rocket engines: they are only suitable for testing the premixed combustion characteristics of solid propellants with their own oxidizers. However, the core working mechanism of solid-liquid rocket engines is diffusion combustion, where an externally supplied oxidizer flows across the surface of the solid fuel, mixes with the fuel pyrolysis gases in the boundary layer, and reacts. Therefore, the aforementioned structures cannot establish a controllable and uniformly distributed oxidizer convection field on the solid fuel surface. Consequently, they cannot simulate and study the convective interaction between the oxidizer and the fuel surface, the diffusion mixing process within the boundary layer, or the flame stabilization mechanism under convective conditions, resulting in a fundamental difference between the experimental environment and the actual working environment of solid-liquid rocket engines.

[0004] In addition, there is a lack of in-situ, visual observation capabilities for the combustion process of micron-sized aluminum particles: the high-speed cameras used in existing technologies mainly record the overall flame morphology and cannot track the entire process of micron-sized aluminum particles agglomeration, detachment, and ignition during combustion.

[0005] Secondly, existing technologies are tested in a static environment, lacking the shearing and carrying effect of the oxidant flow field on the particles, which does not match the real working environment of solid-liquid rocket engines. Therefore, it is difficult to reveal the dynamic combustion behavior of aluminum particles under real diffusion combustion conditions.

[0006] Therefore, there is an urgent need for a testing device and system for testing the diffusion combustion characteristics of aluminum-containing solid fuels, which can, to some extent, solve the problems existing in the current technology. Summary of the Invention

[0007] The purpose of this application is to provide a testing device and system for testing the diffusion combustion characteristics of aluminum-containing solid fuels. By constructing a uniform and controllable oxidizer supply unit to simulate the working environment of solid-liquid rocket engines, and combining non-contact laser ignition with high-speed microscopic photography, the combustion behavior of aluminum particles can be directly captured and visualized for diagnosis.

[0008] This application provides a device for testing the diffusion combustion characteristics of aluminum-containing solid fuels, comprising: An oxidant supply unit that stores oxidant and is capable of supplying oxidant to the outside; The ignition unit has a laser emitting part and an angle adjustment part. The laser emitting part is capable of emitting laser light, and the angle adjustment part is used to adjust the emission angle of the laser light so that the laser light can be focused on the reaction unit. The reaction unit includes a covering section, a rectifier section, and aluminum solid fuel disposed in the rectifier section; the rectifier section is connected to the oxidant supply unit, and the covering section is used to cover the aluminum solid fuel in the rectifier section; and The observation unit is capable of recording the combustion process of the aluminum solid fuel.

[0009] In the above technical solution, the oxidant supply unit further includes: High-pressure oxygen cylinder, containing the aforementioned oxidant; and The main supply pipeline is connected at both ends to the high-pressure oxygen cylinder and the reaction unit, respectively, and the oxidant can be supplied to the reaction unit through the main supply pipeline.

[0010] In the above technical solution, further, a first pressure gauge, a first pressure reducer, a first manual valve and a first check valve are sequentially arranged on the main supply pipeline from the high-pressure oxygen cylinder to the reaction unit.

[0011] In the above technical solution, the aluminum-containing solid fuel diffusion combustion characteristic testing device further includes a quenching unit, which includes: High-pressure nitrogen cylinder, which stores nitrogen gas; and An auxiliary supply pipeline is connected at both ends to the high-pressure nitrogen cylinder and the reaction unit, respectively, and nitrogen can be supplied to the reaction unit through the auxiliary supply pipeline.

[0012] In the above technical solution, further, a second pressure gauge, a second pressure reducer, a second manual valve and a second check valve are sequentially arranged on the auxiliary supply pipeline from the high-pressure nitrogen cylinder to the reaction unit.

[0013] In the above technical solution, the laser emitting part is a carbon dioxide laser, and the angle adjustment part is a corner mirror; The carbon dioxide laser and the corner mirror are arranged at intervals, and the axis of the carbon dioxide laser and the axis of the corner mirror are at a preset angle; The carbon dioxide laser is capable of emitting laser light that extends along a first direction; The corner lens can adjust the laser extending in the first direction to extend in the second direction and focus it on the reaction unit.

[0014] In the above technical solution, the ignition unit further includes: A housing surrounding a mounting cavity for mounting the carbon dioxide laser, wherein the laser emitted by the carbon dioxide laser can pass through the housing and extend along the first direction; and The cooling water tank is connected to the housing via two hoses and is used to introduce circulating cold water into the mounting cavity to cool the carbon dioxide laser.

[0015] In the above technical solution, the rectifier is further defined as a rectifier device, and the lower air inlet of the rectifier device is connected to the main supply pipeline and the auxiliary supply pipeline respectively through a venturi tube; the aluminum solid fuel is mounted on the rectifier device through a support frame. The cover is a protective cover, which is used to cover the aluminum solid fuel on the rectifier; the protective cover has an optical window for the laser to pass through.

[0016] In the above technical solution, the observation unit further includes: A standard high-speed camera is mounted on one side of the protective cover to capture the macroscopic flame structure of the aluminum solid fuel; A high-speed microscopic camera is disposed on one side of the protective cover and spaced apart from the conventional high-speed camera. The high-speed microscopic camera is used to capture the combustion behavior of micro-aluminum solid fuel in an oxidant atmosphere; and A high-speed thermometer is located on one side of the protective cover and is arranged at intervals with the high-speed microscopic camera. The high-speed thermometer is used to photograph the temperature field distribution of the surface of the aluminum solid fuel and the flame.

[0017] This application also provides a system for testing the diffusion combustion characteristics of aluminum-containing solid fuels, including the aforementioned device for testing the diffusion combustion characteristics of aluminum-containing solid fuels.

[0018] Compared with the prior art, this application has the following beneficial effects: This application provides a device for testing the diffusion combustion characteristics of aluminum-containing solid fuels, comprising: An oxidant supply unit that stores oxidant and is capable of supplying oxidant to the outside; The ignition unit has a laser emitting part and an angle adjustment part. The laser emitting part is capable of emitting laser light, and the angle adjustment part is used to adjust the emission angle of the laser light so that the laser light can be focused on the reaction unit. The reaction unit includes a covering section, a rectifier section, and aluminum solid fuel disposed in the rectifier section; the rectifier section is connected to the oxidant supply unit, and the covering section is used to cover the aluminum solid fuel in the rectifier section; and The observation unit is capable of recording the combustion process of the aluminum solid fuel.

[0019] In summary, this application comprises four interconnected parts: an oxidant supply unit, an ignition unit, a reaction unit, and an observation unit. Oxygen enters the reaction unit after passing through a series of piping components, while aluminum-containing solid fuel is fixed at the center of the rectifier. A transparent quartz glass protective cover is positioned above the rectifier, with an optical window at its top that serves as both an exhaust and light path. A carbon dioxide laser is horizontally mounted, and the laser beam, after being refracted by a corner mirror, is vertically focused downwards through the optical window onto the end face of the aluminum solid fuel.

[0020] A standard high-speed camera, a high-speed thermometer, and a high-speed microscopic camera are placed on the side of the protective cover. The standard high-speed camera is used to photograph the macroscopic flame structure, the high-speed thermometer is used to photograph the temperature field distribution of the sample surface and the flame, and the high-speed microscopic camera can capture the combustion behavior of micron-sized aluminum particles in an oxidant atmosphere.

[0021] At the start of the experiment, oxygen, after being pressure-reduced and flow-limited by a fixed venturi tube, enters the rectifier, where it is rectified into a uniform upward oxidant flow field that encapsulates the aluminum-containing solid fuel, creating a diffusion combustion flow field environment. The carbon dioxide laser activates upon receiving a pulse signal, and the laser beam ignites the aluminum-containing solid fuel end face non-contactly. During this process, the high-speed observation module is simultaneously triggered, microscopically recording the entire ignition and combustion process. When the experiment ends or requires emergency interruption, nitrogen is injected by the purging module to safely extinguish the flame.

[0022] This application also provides a system for testing the diffusion combustion characteristics of aluminum-containing solid fuels, including the aforementioned device for testing the diffusion combustion characteristics of aluminum-containing solid fuels. Therefore, it possesses all the beneficial effects of the aforementioned device for testing the diffusion combustion characteristics of aluminum-containing solid fuels, which will not be elaborated upon here. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 A schematic diagram of the structure of the aluminum-containing solid fuel diffusion combustion characteristic testing device provided in this application; Figure 2 A schematic diagram of the oxidant supply unit in the aluminum-containing solid fuel diffusion combustion characteristic testing device provided in this application.

[0025] Reference numerals: 1-Oxidant supply unit; 101-High-pressure oxygen cylinder; 102-Main supply pipeline; 103-First pressure gauge; 104-First pressure reducer; 105-First manual valve; 106-First check valve; 107-High-pressure nitrogen cylinder; 108-Auxiliary supply pipeline; 109-Second pressure gauge; 110-Second pressure reducer; 111-Second manual valve; 112-Second check valve; 113-Power supply; 201-Laser emitting unit; 202-Angle adjustment unit; 203-Housing; 204-Carbon dioxide laser; 205-Corner mirror; 206-Mounting cavity; 207-Cooling water tank; 208-Hose; 301 - Enclosure; 302 - Rectifier; 303 - Aluminum solid fuel; 304 - Rectifier device; 305 - Venturi tube; 306 - Protective cover; 307 - Optical window; 402 - Ordinary high-speed camera; 403 - Microscopic high-speed camera; 404 - High-speed thermometer; 405 - Computer. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0027] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0028] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0029] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0030] The following disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. Additionally, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0031] This application provides a testing device for the diffusion combustion characteristics of aluminum-containing solid fuel, aiming to simulate the diffusion combustion process under the real working environment of solid-liquid rocket engines and achieve in-situ, visualized observation of the combustion behavior of micron-sized aluminum particles. Existing technologies, such as the testing device disclosed in CN104596768 B, are mainly suitable for testing the premixed combustion of solid propellants. Their structure includes a laser, a pressure-resistant glass-enclosed reactor, a vacuum pump, and an external observation and acquisition system. However, this device cannot establish a controllable and uniformly distributed oxidizer convection field on the surface of the solid fuel, thus making it difficult to simulate the diffusion mixing process of oxidizer and fuel pyrolysis gases within the boundary layer in solid-liquid rocket engines. Furthermore, existing technologies lack the ability to capture the microscopic behavior of micron-sized aluminum particles during combustion, failing to track their aggregation, detachment, ignition, and other dynamic processes. Moreover, the testing environment is static or quasi-static, lacking the shearing and carrying effect of the oxidizer flow field on the particles, leading to significant deviations between experimental results and real-world conditions. To address the aforementioned issues, this application provides a testing device for the diffusion combustion characteristics of aluminum-containing solid fuels that more closely resembles a real combustion environment by constructing a testing device with uniform and controllable oxidant supply capability and combining non-contact laser ignition with high-speed microscopic photography technology.

[0032] Combination Figure 1As shown, the aluminum solid fuel diffusion combustion characteristic testing device provided in this application mainly includes an oxidant supply unit 1, an ignition unit, a reaction unit, and an observation unit. The oxidant supply unit 1 stores oxidant and can stably supply oxidant to the outside. The ignition unit has a laser emitting section 201 and an angle adjustment section 202. The laser emitting section 201 emits a laser, and the angle adjustment section 202 adjusts the laser emission angle so that the laser can be accurately focused on the aluminum solid fuel 303 in the reaction unit. The reaction unit has a covering section 301, a rectifying section 302, and aluminum solid fuel 303 disposed in the rectifying section 302. The rectifying section 302 is connected to the oxidant supply unit 1, and the covering section 301 covers the aluminum solid fuel 303 inside the rectifying section 302, forming a relatively closed combustion environment. The observation unit records the combustion process of the aluminum solid fuel 303, including the macroscopic flame structure, microscopic particle behavior, and temperature field distribution. With the above structure, this application can simulate the process of oxidant flowing along the fuel surface and undergoing diffusion combustion in solid-liquid rocket engines, filling the gap in the existing technology for observing the behavior of aluminum particles under convective diffusion combustion environment.

[0033] In practical applications, the stability and controllability of the oxidant supply are crucial factors affecting combustion experiment results. Existing technologies often employ a single gas source, making it difficult to achieve precise flow field adjustment and redundancy. To address this issue, this application proposes an alternative implementation method, such as... Figure 2 As shown, the oxidant supply unit 1 includes a high-pressure oxygen cylinder 101 and a main supply pipeline 102. The high-pressure oxygen cylinder 101 stores oxidant. The two ends of the main supply pipeline 102 are connected to the high-pressure oxygen cylinder 101 and the reaction unit, respectively, allowing the oxidant to be supplied to the reaction unit. To further improve the safety and adjustment accuracy of the gas supply system, a first pressure gauge 103, a first pressure reducer 104, a first manual valve 105, and a first check valve 106 are sequentially installed on the main supply pipeline 102 from the high-pressure oxygen cylinder 101 to the reaction unit. The first pressure gauge 103 is used to monitor the pipeline pressure, the first pressure reducer 104 is used to reduce the pressure of the high-pressure oxygen to the working pressure required for the experiment, the first manual valve 105 is used to control the opening and closing of the gas path, and the first check valve 106 is used to prevent high-temperature gas from the reaction unit from flowing back into the gas supply pipeline, ensuring system safety. In addition, the gas supply pipeline can also use a mass flow controller to replace the combination of manual valve and pressure regulator, so as to achieve closed-loop precise control of oxidant flow, which is suitable for experimental scenarios that are sensitive to flow fluctuations.

[0034] In another optional embodiment, this application further includes a purge unit, which comprises a high-pressure nitrogen cylinder 107 and an auxiliary supply pipeline 108. The high-pressure nitrogen cylinder 107 stores nitrogen gas. The auxiliary supply pipeline 108 is connected at both ends to the high-pressure nitrogen cylinder 107 and the reaction unit, respectively, allowing nitrogen gas to be supplied to the reaction unit. Along the auxiliary supply pipeline 108, from the high-pressure nitrogen cylinder 107 to the reaction unit, a second pressure gauge 109, a second pressure reducer 110, a second manual valve 111, and a second check valve 112 are sequentially arranged. When the test ends or an emergency interruption is required, the auxiliary pipeline can safely purge the nitrogen.

[0035] The ignition unit is a key module for achieving non-contact ignition of solid fuel. In solid-liquid rocket engines, the ignition process often needs to be carried out in the presence of an oxidizer flow field. Traditional electric heating wire ignition methods are prone to interfering with the flow field and are difficult to achieve precise timing control. To address this issue, this application adopts a laser ignition method. In one specific embodiment, the laser emitting unit 201 uses a carbon dioxide laser 204 (powered by power supply 113), and the angle adjustment unit 202 uses a corner mirror 205. The carbon dioxide laser 204 and the corner mirror 205 are arranged at intervals, and the axis of the carbon dioxide laser 204 forms a preset angle with the axis of the corner mirror 205. The carbon dioxide laser 204 can emit laser light extending in a first direction, and the corner mirror 205 can adjust the laser light extending in the first direction to extend in a second direction and focus it on the surface of the aluminum solid fuel 303 in the reaction unit. The advantage of using a corner mirror instead of a plane mirror is that the corner mirror has higher reflection accuracy and optical path stability, which can reduce the energy loss of the laser during transmission and ensure the positional accuracy of the focal point. In one extended embodiment, the angle adjustment unit 202 may also employ a two-dimensional scanning galvanometer system. By controlling the deflection angle of the galvanometer, the laser focus can be moved in two dimensions, thereby enabling ignition at different positions on the fuel surface or simultaneous ignition at multiple points. This is suitable for studying the influence of ignition position on combustion propagation characteristics.

[0036] Lasers generate a large amount of heat during operation. If this heat is not dissipated in time, it will affect the stability of the laser output and its lifespan. Therefore, in one optional embodiment of this application, the ignition unit further includes a housing 203 and a cooling water tank 207. The housing 203 surrounds a mounting cavity 206 for mounting a carbon dioxide laser 204. The laser emitted by the carbon dioxide laser 204 can pass through the housing 203 and extend along a first direction. The cooling water tank 207 is connected to the housing 203 via two flexible hoses 208, used to introduce circulating cold water into the mounting cavity 206 to cool the carbon dioxide laser 204. After absorbing heat, the cooling water flows back to the cooling water tank 207, is cooled, and then recycled, forming a closed-loop cooling system. In an extended embodiment, the cooling system can also employ a combination of semiconductor cooling chips and air cooling, suitable for experimental scenarios under waterless conditions, or for precision experiments requiring higher laser temperature control. In addition, a temperature sensor and temperature control module can be installed in the cooling water tank 207 to monitor the water temperature in real time and automatically adjust the cooling water flow to ensure that the laser always works within the optimal temperature range.

[0037] The reaction unit is the core area for constructing the oxidant flow field and for fuel combustion. To form a uniform and stable oxidant flow field on the solid fuel surface, in one specific embodiment of this application, the rectifying section 302 employs a rectifying device 304. The lower air inlet of the rectifying device 304 is connected to the main supply line 102 and the auxiliary supply line 108 via a venturi tube 305. The venturi tube 305 can limit and stabilize the incoming airflow, reducing airflow pulsation and improving the uniformity of the flow field. The aluminum solid fuel 303 is mounted above the rectifying device 304 via a support frame, exposing its end face to the oxidant flow field. The covering section 301 employs a protective cover 306, which covers the aluminum solid fuel 303 above the rectifying device 304, forming a relatively enclosed combustion chamber. The protective cover 306 has an optical window 307 for laser transmission. This window is made of an infrared-transmitting material, such as zinc selenide or zinc sulfide, to ensure that the laser can efficiently pass through and focus on the fuel surface. In one extended design, the rectifier 304 can employ a honeycomb rectifier or a porous media rectifier to further optimize the uniformity of the flow field and the intensity of turbulence, simulating the flow field characteristics under different engine operating conditions. The protective cover 306 can also be designed as a sandwich structure, with a cooling medium circulated in the inner layer to withstand the thermal shock of high-temperature combustion products and extend its service life. Furthermore, an exhaust channel can be provided on the top of the protective cover 306 to discharge combustion products and maintain pressure stability within the combustion chamber. A back pressure valve can be installed on the exhaust channel to simulate the combustion environment at different altitudes.

[0038] The observation unit is crucial for achieving visualized diagnosis of the combustion process. In existing technologies, high-speed cameras are mainly used to record the overall flame morphology, making it difficult to capture the combustion behavior of micron-sized aluminum particles. To address this issue, in one specific embodiment of this application, the observation unit includes a conventional high-speed camera 402, a microscopic high-speed camera 403, and a high-speed thermometer 404. The conventional high-speed camera 402 is positioned on one side of the protective cover 306 and is used to photograph the macroscopic flame structure of the aluminum solid fuel 303, recording macroscopic parameters such as flame propagation speed and flame height. The microscopic high-speed camera 403 is positioned on one side of the protective cover 306 and is spaced apart from the conventional high-speed camera 402. The microscopic high-speed camera 403 is equipped with a long working distance microscope lens, capable of capturing the combustion behavior of micron-sized aluminum particles in an oxidant atmosphere, including the entire process of particle aggregation, detachment, ignition, combustion, and extinguishing. A high-speed thermometer 404 is positioned on one side of the protective cover 306 and is spaced apart from the high-speed microscopic camera 403. The high-speed thermometer 404 employs infrared thermal imaging technology to capture the temperature field distribution on the surface of the aluminum solid fuel 303 and the flame, obtaining temperature change curves during combustion. In an extended embodiment, the observation unit can also integrate a spectrometer for real-time acquisition of flame emission spectra. By inverting the types and concentrations of combustion products through characteristic spectral lines, the combustion reaction mechanism can be further revealed. The high-speed microscopic camera 403 can be equipped with an electrically adjustable focusing mechanism to achieve automatic focusing and imaging of combustion zones at different depths. The high-speed thermometer 404 can employ dual-color temperature measurement technology to reduce the impact of changes in fuel surface emissivity on measurement accuracy.

[0039] To facilitate the synchronous acquisition and analysis of experimental data, this application also includes a computer 405 in one optional embodiment. The computer 405 is connected to a carbon dioxide laser 204, a conventional high-speed camera 402, a high-speed microscope camera 403, and a high-speed thermometer 404 via a synchronous trigger signal, enabling synchronous startup and data acquisition of multiple devices. During the experiment, the computer 405 records combustion images, temperature data, and parameters such as pressure and flow rate in real time, and performs post-processing analysis using dedicated software to extract key characteristic parameters such as ignition delay time, combustion rate, and flame structure evolution. In an extended embodiment, the computer 405 can also integrate machine learning algorithms to automatically identify and classify a large number of combustion images, recognizing the combustion patterns and abnormal behaviors of aluminum particles, thereby improving the efficiency and accuracy of data analysis. Furthermore, the computer 405 can remotely operate the gas supply system, ignition system, and observation system via a remote control module, enhancing the safety and convenience of the experiment.

[0040] This application also provides a testing system for the diffusion combustion characteristics of aluminum-containing solid fuels, including the testing device for the diffusion combustion characteristics of aluminum-containing solid fuels described in any of the above embodiments. This testing system can simulate the diffusion combustion process under the real working environment of solid-liquid rocket engines, achieving comprehensive diagnosis of the combustion behavior of aluminum fuels. It is suitable for applications such as solid rocket propulsion technology research, fuel formulation optimization, and combustion mechanism exploration. In an extended embodiment, the testing system can also integrate a fuel supply unit for online preparation or replacement of aluminum-containing solid fuels with different formulations, improving experimental efficiency. The fuel supply unit can employ extrusion molding or casting molding processes to achieve precise control over the size, shape, and aluminum powder content of fuel samples. Furthermore, the testing system can be configured with an environmental simulation unit to adjust the initial temperature, pressure, and humidity within the combustion chamber, studying the combustion characteristics of fuels under different environmental conditions. The environmental simulation unit can be implemented using a combination of heating belts, cooling coils, and humidifiers, or by placing the entire reaction unit within a small environmental chamber to achieve a wider range of environmental parameter adjustments.

[0041] In summary, this application constructs a test device capable of simulating the diffusion combustion flow field environment of a solid-liquid rocket engine through the collaborative design of an oxidizer supply unit, an ignition unit, a reaction unit, and an observation unit. The oxidizer supply unit adopts a dual-path gas supply structure, combined with pressure and flow control elements, to achieve precise adjustment and safety redundancy of the oxidizer flow field. The ignition unit uses a combination of a carbon dioxide laser and a corner mirror to achieve non-contact, precise ignition, avoiding interference with the flow field. The reaction unit forms a uniform flow field and a closed combustion space through a rectifier and a protective shield, ensuring the stability and repeatability of the combustion process. The observation unit integrates macroscopic, microscopic, and thermal imaging equipment to achieve simultaneous recording of the combustion process across multiple scales and physical fields. The modules are coordinated and controlled by a computer for data acquisition, forming a complete combustion characteristic testing platform. Compared with existing technologies, this application can achieve in-situ observation of the combustion behavior of aluminum particles under convective diffusion combustion conditions, filling a gap in this field and providing important experimental means for the research and development of solid-liquid rocket engine fuels and combustion mechanisms.

[0042] In one extended embodiment, the testing apparatus of this application can also be used to study the combustion characteristics of other metallic fuels such as boron- and magnesium-containing fuels, simply by changing the fuel sample and adjusting the oxidizer supply parameters. The modular design of the testing apparatus gives it excellent scalability and adaptability, capable of meeting the testing needs of different fuel types and combustion conditions. Furthermore, the protective cover and rectifier of this application can be made of high-temperature alloy materials, suitable for experimental scenarios with higher combustion temperatures. The observation window can be designed to be replaceable to adapt to the optical observation requirements of different wavelengths. The gas supply pipeline can be made of stainless steel or polytetrafluoroethylene to withstand the chemical corrosiveness of different oxidizers. All components in contact with high-temperature gases can be designed with a water-cooled structure to improve the durability and safety of the apparatus.

[0043] In summary, the aluminum-containing solid fuel diffusion combustion characteristic testing device and system provided in this application, through reasonable structural design and functional integration, effectively solves the problems of existing technologies, such as the inability to simulate diffusion combustion flow fields and the inability to capture the microscopic combustion behavior of aluminum particles, providing an advanced experimental platform for solid rocket propulsion technology research. The technical solution of this application not only has high practical value but also lays a technical foundation for in-depth research in related fields.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A device for testing the diffusion combustion characteristics of aluminum-containing solid fuels, characterized in that, include: An oxidant supply unit that stores oxidant and is capable of supplying oxidant to the outside; The ignition unit has a laser emitting part and an angle adjustment part. The laser emitting part is capable of emitting laser light, and the angle adjustment part is used to adjust the emission angle of the laser light so that the laser light can be focused on the reaction unit. as well as The reaction unit includes a covering section, a rectifier section, and aluminum solid fuel disposed in the rectifier section; the rectifier section is connected to the oxidant supply unit, and the covering section is used to cover the aluminum solid fuel in the rectifier section. The observation unit is capable of recording the combustion process of the aluminum solid fuel.

2. The device for testing the diffusion combustion characteristics of aluminum-containing solid fuels according to claim 1, characterized in that, The oxidant supply unit includes: High-pressure oxygen cylinder, containing the aforementioned oxidant; and The main supply pipeline is connected at both ends to the high-pressure oxygen cylinder and the reaction unit, respectively, and the oxidant can be supplied to the reaction unit through the main supply pipeline.

3. The apparatus for testing the diffusion and combustion characteristics of aluminum-containing solid fuels according to claim 2, characterized in that, The main supply pipeline is provided with a first pressure gauge, a first pressure reducer, a first manual valve, and a first check valve in sequence from the high-pressure oxygen cylinder to the reaction unit.

4. The apparatus for testing the diffusion combustion characteristics of aluminum-containing solid fuels according to claim 2, characterized in that, The aluminum-containing solid fuel diffusion combustion characteristic testing device further includes a quenching unit, which comprises: High-pressure nitrogen cylinder, which stores nitrogen gas; and An auxiliary supply pipeline is connected at both ends to the high-pressure nitrogen cylinder and the reaction unit, respectively, and nitrogen can be supplied to the reaction unit through the auxiliary supply pipeline.

5. The apparatus for testing the diffusion and combustion characteristics of aluminum-containing solid fuels according to claim 4, characterized in that, The auxiliary supply pipeline is provided with a second pressure gauge, a second pressure reducer, a second manual valve, and a second check valve in sequence from the high-pressure nitrogen cylinder to the reaction unit.

6. The apparatus for testing the diffusion combustion characteristics of aluminum-containing solid fuels according to claim 1, characterized in that, The laser emitting part is a carbon dioxide laser, and the angle adjustment part is a corner mirror; The carbon dioxide laser and the corner mirror are arranged at intervals, and the axis of the carbon dioxide laser and the axis of the corner mirror are at a preset angle; The carbon dioxide laser is capable of emitting laser light that extends along a first direction; The corner lens can adjust the laser extending in the first direction to extend in the second direction and focus it on the reaction unit.

7. The apparatus for testing the diffusion and combustion characteristics of aluminum-containing solid fuels according to claim 6, characterized in that, The ignition unit further includes: A housing surrounding a mounting cavity for mounting the carbon dioxide laser, wherein the laser emitted by the carbon dioxide laser can pass through the housing and extend along the first direction; and The cooling water tank is connected to the housing via two hoses and is used to introduce circulating cold water into the mounting cavity to cool the carbon dioxide laser.

8. The apparatus for testing the diffusion and combustion characteristics of aluminum-containing solid fuels according to claim 4, characterized in that, The rectifier section is a rectifier device, and the lower air inlet of the rectifier device is connected to the main supply pipeline and the auxiliary supply pipeline respectively through a venturi tube; the aluminum solid fuel is mounted on the rectifier device through a support frame; The cover is a protective cover, which is used to cover the aluminum solid fuel on the rectifier; the protective cover has an optical window for the laser to pass through.

9. The apparatus for testing the diffusion and combustion characteristics of aluminum-containing solid fuels according to claim 8, characterized in that, The observation unit includes: A standard high-speed camera is mounted on one side of the protective cover to capture the macroscopic flame structure of the aluminum solid fuel; A high-speed microscopic camera is disposed on one side of the protective cover and spaced apart from the conventional high-speed camera. The high-speed microscopic camera is used to capture the combustion behavior of micro-aluminum solid fuel in an oxidant atmosphere; and A high-speed thermometer is located on one side of the protective cover and is arranged at intervals with the high-speed microscopic camera. The high-speed thermometer is used to photograph the temperature field distribution of the surface of the aluminum solid fuel and the flame.

10. A testing system for the diffusion combustion characteristics of aluminum-containing solid fuels, characterized in that, The apparatus includes the aluminum-containing solid fuel diffusion combustion characteristic testing device as described in any one of claims 1-9.

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