Multi-mode combustion experiment device for plasma combustion supporting

Abstract

The invention discloses a multi-mode combustion experiment device for plasma combustion supporting. The multi-mode combustion experiment device comprises a laser incidence part, a combustion chamber and a material supply part. The laser incidence part is arranged at the top of the combustion chamber and used for guiding laser into the combustion chamber for ignition; the combustion chamber is composed of an end face connecting part and a combustion cavity, two symmetrical observation windows and a conduction window are formed in the outer wall of the combustion cavity, and the vertical face of the conduction window is perpendicular to the vertical faces of the observation windows. The material supply component is arranged at the bottom of the combustion chamber and used for guiding reactants into the combustion chamber. The material supply part is a water-gas balance box body or a material supply disc, and the water-gas balance box body can generate water vapor to create a water vapor environment required by an experiment. The experimental device has multiple experimental functions, dynamic or static combustion characteristics and influence factors of the metal fuel in different atmosphere environments with / without plasma injection can be better observed and researched, and powerful support is provided for research and innovation of multiple forms of plasma combustion-supporting technologies.

Description

Technical Field

[0001] The present application relates to a multi-mode combustion experimental device for plasma-assisted combustion, belonging to the field of combustion testing. Background Art

[0002] Combustion, as an important way of energy utilization, is widely used in many fields such as industry, transportation, and power generation. However, traditional combustion technology often has the problem of low combustion efficiency, especially in solid engines. The working environment of solid engines is harsh, and the propellant and the high-energy particles contained therein often cannot be burned efficiently and completely, thus affecting the overall engine performance. In order to improve combustion performance, various combustion enhancement technologies continue to emerge, and plasma-assisted combustion technology is one of the most promising technologies.

[0003] The application of plasma technology in the field of combustion provides a new approach to solving the above problems. Plasma is the fourth state of matter, containing a large number of highly active particles, such as electrons, ions, free radicals, etc. These particles can significantly affect the combustion chemical reaction process. Early plasma combustion-supported technologies were mainly based on non-thermal plasmas, such as corona discharge and dielectric barrier discharge. Although these technologies can improve combustion performance to a certain extent, they have problems such as insufficient energy injection and low concentration of active particles, which limit their effectiveness in practical applications.

[0004] However, the existing plasma combustion-supported experimental devices have many shortcomings, such as complex structure, inconvenient operation, high cost or unsatisfactory combustion-supporting effect, which greatly restricts the in-depth research of plasma combustion-supported technology and also restricts its further development and application. At present, in the field of plasma combustion-supported, there is a lack of an experimental device that can accurately control plasma parameters, monitor the combustion process in real time, and accurately evaluate the combustion-supporting effect. Traditional combustion experimental devices are difficult to meet the needs of in-depth research on the plasma combustion-supported mechanism and cannot provide strong support for the optimization and innovation of plasma combustion-supported technology.

[0005] With the in-depth understanding of the chemical reaction kinetics and thermodynamics in the combustion process, there is an urgent need for an experimental device that can simulate the plasma combustion-supporting effect under different working conditions to promote the development of this technology in practical applications. Summary of the invention

[0006] In order to solve the above problems, the present application proposes a multimodal combustion experimental device for plasma-assisted combustion, which can better observe and study the influencing factors and trends of multimodal combustion of metals or metal fuels with or without plasma injection under different gas components. This device can provide rich data support for optimizing the combustion process in multimodal combustion exploration, help analyze the specific effects of various gas components on reaction rate, efficiency and stability, thereby promoting combustion-related technological innovations.

[0007] According to one aspect of the present application, a multi-mode combustion experimental device for plasma-assisted combustion is provided, comprising a laser incident component, a combustion chamber, and a material supply component;

[0008] The laser incident component is arranged at the top of the combustion chamber, and is used to introduce laser into the combustion chamber for ignition; the combustion chamber is composed of an end surface connection part and a combustion cavity, and the outer wall of the combustion cavity is provided with two symmetrical observation windows and a conduction window, and the vertical surface of the conduction window is perpendicular to the vertical surface of the observation window; the combustion cavity is a hollow cylindrical cavity, and the length ratio of the bottom diameter to the height is 1:3; the conduction window is arranged close to the bottom of the combustion cavity, and the plane where the conduction window is located is the front, and the front projection area of ​​the conduction window is 15%-18% of the front projection area of ​​the combustion cavity;

[0009] The material supply component is arranged at the bottom of the combustion chamber, and is used for introducing reactants into the combustion chamber; the material supply component is a water-gas balance box or a feed tray, and the water-gas balance box can generate water vapor to create a water vapor environment required for the experiment.

[0010] Optionally, taking the plane where the conduction window is located as the front, the front projection shape of the conduction window is a rectangle, and the central axis of the rectangle coincides with the central axis of the front projection of the combustion chamber.

[0011] Optionally, the length ratio of the base to the height of the rectangle is 1:2, and the upper base of the rectangle is set at 1 / 2 of the height of the combustion chamber, and the lower base is set between 1 / 4 and 1 / 6 of the height of the combustion chamber.

[0012] Optionally, each of the observation windows is composed of a plurality of independent windows that are evenly distributed along the axial direction.

[0013] Optionally, the length of the independent window cannot exceed half the wavelength of the microwave frequency.

[0014] Optionally, the outer wall of the combustion chamber is further provided with a plurality of gas transport holes and a pressure detection hole.

[0015] Optionally, four gas delivery holes are opened, wherein two gas delivery holes are arranged near the top of the combustion chamber, and two gas delivery holes are arranged near the bottom of the combustion chamber.

[0016] Optionally, the end surface connection portion includes a first connection portion and a second connection portion, the laser incident component is connected and fixed to the first connection portion, and the material supply component is connected and fixed to the second connection portion.

[0017] Optionally, the laser incident component includes an incident window end cover, a glass seal and a sealing flange which are connected in sequence, and the sealing flange is connected to the first connecting portion.

[0018] Optionally, the water-gas balance box includes several heating components and a water tank; the top of the water tank is connected to the second connecting part, and a propulsion boss is provided at the bottom of the water tank, and a through hole is provided on the top surface of the propulsion boss, and the propulsion boss is used to connect to an external propulsion device to transport reactants.

[0019] The beneficial effects of this application include but are not limited to:

[0020] 1. The multi-modal combustion experimental device for plasma-assisted combustion provided in the present application determines the shape and specific size ratio of the combustion chamber by using the Q factor (quality factor) obtained by microwave electromagnetic numerical simulation calculation, and at the same time uses electromagnetic simulation calculation to limit the position and size of the conduction window. The two are further optimized and designed at the same time. The final combustion chamber structure is most conducive to the input of microwave energy, effectively reduces the reflection and loss of microwave energy, and can also achieve precise control of plasma parameters.

[0021] 2. The multimodal combustion experimental device for plasma-assisted combustion provided in the present application can effectively prevent the leakage of microwave energy by limiting the length and distribution of the observation windows, and can also enable scientific researchers to observe and record the dynamic changes of the combustion process in real time during the experiment, and record key parameters, which is helpful to analyze the combustion performance of materials under different plasma conditions and provide real-time data support to optimize the experimental conditions; and the symmetrical observation windows on both sides adopt a split design, which not only ensures that the plasma energy input is not leaked, but also ensures sufficient optical imaging diagnosis space.

[0022] 3. The multi-modal combustion experimental device for plasma-assisted combustion provided in this application sets a water-gas balance box or a feed tray as a material supply component, and researchers can choose according to actual needs, which enables the device to easily switch to a pure water vapor combustion environment or a combination of other gases. Different gases and their different proportions and reactant types can be used. This "multi-modal" approach greatly enhances the controllability and adaptability of the experiment, and provides a wealth of options for experiments under different combustion conditions.

[0023] 4. The multi-modal combustion experimental device for plasma-assisted combustion provided in the present application and the setting of the water-vapor balance box realize the circulation of water vapor in the experimental cavity, which solves the problem of water vapor condensation. At the same time, the matching design of the water tank and the combustion chamber can realize the rapid creation of a large-flow water atmosphere. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0025] Figure 1 This is a three-dimensional structural diagram of a multi-mode combustion experimental device for plasma-assisted combustion (the material supply component is a water-gas balance box) involved in Example 1 of the present application;

[0026] Figure 2 A three-dimensional structural diagram of a multi-mode combustion experimental device (excluding material supply components) for plasma-assisted combustion according to an embodiment of the present application;

[0027] Figure 3 This is a three-dimensional structural diagram of the water-gas balance box involved in Example 1 of the present application;

[0028] Figure 4 This is a front view of the water-gas balance box involved in Example 1 of the present application;

[0029] Figure 5 for Figure 4 Section view along AA direction;

[0030] Figure 6 A side view of a combustion chamber according to an embodiment of the present application;

[0031] Figure 7 for Figure 6 Side cross-sectional view after cutting along direction BB.

[0032] List of parts and reference numerals:

[0033] 1. Laser incident component; 2. Combustion chamber; 3. Material supply component; 4. First connecting part; 5. Combustion cavity; 6. Conduction window; 7. Rectangle; 8. Observation window; 9. Second connecting part; 10. Incident window end cover; 11. Sealing flange; 12. Pressure detection hole; 13. Air inlet; 14. Exhaust hole; 15. Propulsion boss; 16. Assembly flange; 17. Water inlet; 18. Water tank; 19. Independent window; 20. Reinforcement rib; 21. Through hole. DETAILED DESCRIPTION

[0034] In order to more clearly illustrate the overall concept of the present application, a detailed description is given below in an illustrative manner in conjunction with the accompanying drawings.

[0035] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0036] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited to the specific embodiments disclosed below.

[0037] In addition, in the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0038] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0039] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0040] In the present application, unless otherwise clearly specified and limited, a first feature "above" or "below" a second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more embodiments or examples.

[0041] The "multimodal" of this application refers to the fact that various forms of experiments can be conducted. First, different components of gas enter the experimental chamber through the air inlet. If there is a large proportion of water vapor in the gas components, a device containing a water-gas balance box is used, which can realize the circulation of water vapor and facilitate the creation of an experimental environment; secondly, by adjusting the speed of the external feed cylinder ejection, the combustion of metal particles at different speeds including static conditions can be achieved; finally, the entire experimental device can not only study the combustion of metal particles, but also change the metal particles into propellants for combustion experiments.

[0042] Example 1 (Material supply component is a water-gas balance box)

[0043] refer to Figure 1-Figure 2 , the embodiment of the present application discloses a multi-mode combustion experimental device for plasma-assisted combustion, comprising a laser incident component 1, a combustion chamber 2 and a material supply component 3;

[0044] The laser incident component 1 is arranged at the top of the combustion chamber 2, and is used to introduce laser into the combustion chamber 2 for ignition; the combustion chamber 2 is composed of an end face connection part and a combustion cavity 5, and the outer wall of the combustion cavity 5 is provided with two symmetrical observation windows and a conduction window 6, and the vertical surface of the conduction window 6 is perpendicular to the vertical surface of the observation window; the combustion cavity 5 is a hollow cylindrical cavity, and the length ratio of the bottom diameter to the height is 1:3; in this embodiment, the bottom diameter is 90mm, and the internal height of the combustion cavity 5 is 270mm.

[0045] The conduction window 6 is arranged near the bottom of the combustion chamber 5, with the plane where the conduction window 6 is located as the front. In this embodiment, the front projection area of ​​the conduction window 6 is 15%-18% of the front projection area of ​​the combustion chamber 5; the material supply component 3 is arranged at the bottom of the combustion chamber 2, and is used to introduce reactants into the combustion chamber 2; the material supply component 3 is a water-gas balance box or a supply tray, and the water-gas balance box can generate water vapor to create the water vapor environment required for the experiment.

[0046] refer to Figure 7 As an implementation method, the plane where the conduction window 6 is located is the front, and the front projection of the conduction window 6 is a rectangle 7, and the central axis of the rectangle 7 coincides with the central axis of the front projection of the combustion chamber 5. The front projection inside the combustion chamber 5 is equivalent to a large rectangle, and the front projection position of the conduction window 6 needs to be in the middle in the horizontal direction and below the middle in the vertical direction.

[0047] Specifically, the combustion chamber 5 is made of 304 stainless steel, which has good resistance to high temperature and water vapor corrosion.

[0048] Further, the length ratio of the base to the height of the rectangle 7 formed by the front projection of the conduction window 6 is 1:2, and the upper base of the rectangle 7 is set at 1 / 2 of the height of the combustion chamber 5, and the lower base is set between 1 / 4 and 1 / 6 of the height of the combustion chamber 5. In this embodiment, the base of the rectangle 7 is 43.2 mm and the height is 86.4 mm.

[0049] refer to Figure 6 Each observation window 8 is composed of a number of independent windows 19 evenly distributed along the axial direction. Further, the length of the independent window 19 cannot exceed half the wavelength of the microwave frequency.

[0050] In this embodiment, two observation windows 8 with an overall size of 130×30 mm are arranged symmetrically, and the independent windows 19 are distributed in sections in the axial direction. There are 3 independent windows 19 in total, and each section is 5 mm apart. Each independent window 19 is 40 mm long, which is smaller than the half wavelength (about 60 mm) of the commonly used experimental microwave frequency. It can prevent the leakage of microwave energy and facilitate the observation of the combustion experiment, and comprehensively considers the limitations and needs of both.

[0051] As an embodiment, the outer wall of the combustion chamber 5 is also provided with four gas transport holes and a pressure detection hole 12. The four circular holes for gas injection and discharge on the combustion chamber 2 are arranged near the top and bottom of the combustion chamber 5, two at the bottom and two at the top, respectively. The two at the bottom are air inlet holes 13, and the two at the top are air exhaust holes 14, both with an inner diameter of 4 mm. The inner diameter of the pressure detection hole 12 is 2 mm, and it is arranged near the top of the combustion chamber 5.

[0052] As an embodiment, the end face connection part includes a first connection part 4 and a second connection part 9, the laser incident component 1 is connected and fixed to the first connection part 4, and the material supply component 3 is connected and fixed to the second connection part 9; the laser incident component 1 includes an incident window end cover 10, a glass seal and a sealing flange 11 connected in sequence, and the sealing flange 11 is connected to the first connection part 4.

[0053] The first connecting part 4 and the second connecting part 9 are flanges of the same specification. The laser incident window end cover 10 has a thickness of 10 mm and a through hole 21 in the middle. The inner surface through hole 21 has a diameter of 52 mm and an outer surface diameter of 40 mm. Eight M5 bolt holes are reserved thereon. The sealing flange 11 is provided with a truncated cone and is fixed to the laser incident window end cover 10 by bolts. A 24 mm high space is reserved in the middle for loading quartz glass with a diameter of 52 mm and a height of 23 mm and a matching sealing gasket (glass seal). The lower surface of the sealing flange 11 is fixed to the flange of the first connecting part 4 by eight M10 bolts. At the same time, a limit groove and an O-ring groove are provided at the connection to keep the experimental device coaxial and sealed.

[0054] refer to Figure 3-Figure 5As an embodiment, the water-gas balance box includes four heating components and a water tank 18; the top of the water tank 18 is connected to the second connecting portion 9, and a propulsion boss 15 is provided at the bottom of the water tank 18. A through hole 21 is provided on the top surface of the propulsion boss 15, and the propulsion boss 15 is used to connect to an external propulsion device to transport reactants.

[0055] Specifically, the heating component is a heating rod (not shown in the figure) and an external power supply. Five assembly flanges 16 are set on the upper surface of the water tank 18. The middle assembly flange 16 is fixed to the flange of the second connecting part 9 of the combustion chamber 5 by 8 M10 bolts. At the same time, the connection is equipped with a limit groove and an O-ring groove to keep the experimental device coaxial and sealed.

[0056] The four outer assembly flanges 16 are connected with four industrial fixed-value heating rods using six M5 bolts to heat the water in the water tank 18 to produce a corresponding gas environment for the experiment. The surface is provided with an O-ring of matching size for sealing. The cavity size of the water tank 18 is 390×390×200mm, with an overall thickness of 5mm. Two 12mm thick reinforcing ribs 20 are provided on the internal upper surface to ensure the support of the upper cavity cover and other two parts.

[0057] A water inlet 17 with an inner diameter of 15 mm is provided on the side of the water tank 18 cavity. The thrust boss 15 is a 100 mm diameter concave cylinder for connecting a long-stroke small cylinder to deliver reactants. There is a coaxial through hole 21 with an inner diameter of 15 mm, which is the channel for transporting reactants. In the experiment, the water in the water tank 18 is heated by the heating rod to become water vapor and fill into the combustion cavity 5, creating the water vapor environment required for the experiment.

[0058] If the device needs to be connected to an external fuel supply device for conducting experiments, after the experimental environment is created, the fuel supply device uses a small long-stroke cylinder to push the reactants into the combustion chamber 5. The ambient gas is provided by a gas cylinder, and the gas cylinder is injected from the lower air inlet of the above-mentioned combustion chamber 5 through a pressure sensor, a gas valve and a flow sensor. The two air inlets can study the combustion environment of a mixture of different gas components, and the gas is discharged from the exhaust hole 14 on the upper side of the above-mentioned combustion chamber 5 through an electric valve.

[0059] Example 2

[0060] The difference between this embodiment and embodiment 1 is that the material supply component 3 adopts a supply tray (not shown in the figure), and the supply tray is directly bolted and fixed to the bottom of the combustion chamber 2 and the external fuel supply device.

[0061] Experimental example

[0062] In order to more clearly illustrate the application of this experimental device in the combustion test, the following entire experimental process is given for understanding. Except for this experimental device, other equipment can be purchased and assembled by technical personnel in the field on the market, and this experimental example will not explain this any more.

[0063] This experimental example uses the device of Example 1 to conduct experiments, using laser ignition. The external laser igniter emits laser, which is adjusted in angle by the emission lens and enters the combustion chamber 5 through the laser incident component 1 to ignite the reactants.

[0064] The diagnostic means used in this experimental example include imaging diagnostic systems such as pressure sensors and high-speed cameras, and non-contact diagnostic means such as transmission spectroscopy and infrared thermometers; wherein the pressure sensor is installed in the pressure detection hole 12 opened on the above-mentioned combustion chamber 5; the high-speed camera and the laser are placed on both sides of the combustion chamber 2, and are arranged in a straight line with the lens and the observation window 8 on the combustion chamber 5 to facilitate the light path; non-contact diagnostic means such as transmission spectroscopy and infrared thermometers perform diagnosis through the observation window 8.

[0065] To conduct a combustion experiment, first assemble the experimental device and various parts, place the metal particles on the top of the cylinder of the propulsion boss 15, place the O-ring on the O-ring groove, bolt the combustion chamber 2 to the upper and lower flanges, install the waveguide, observation window cover, conduction window 6 cover, and laser incident window end cover 10, and use a gasket to contact and seal the glass and window contact surfaces. Connect the two air inlets through the flow sensor and the corresponding supporting pipelines of the electric valve, install the pressure sensor at the same time, and install the electric valve at the exhaust port. The pressure sensor installed on the combustion chamber 5 is also sealed with raw tape.

[0066] Before the experiment, close the two air outlets and one air inlet, and introduce argon into the combustion chamber 5 through the other air inlet until the pressure reaches the pressure set for this experiment, then close the argon inlet electric valve, wait for a while, and see if the pressure sensor value fluctuates. If the pressure value drops, it means that the airtightness of the combustion chamber 5 does not meet the standard, and it is necessary to reinstall the experimental device and repeat the above operations. If there is no fluctuation in the pressure value and the airtightness of the tester is good, open the two air outlets, close the air inlet, turn on the heating rod on the water tank 18, heat the water to create an atmosphere for the reaction between metal and water, close the exhaust valve after a period of time, open the air inlet valve, and introduce the preset gas components of the experiment into the combustion chamber 5 in proportion, and continue to inject water vapor to reach the required ambient gas pressure.

[0067] Set up optical diagnostic equipment, non-contact diagnostic equipment such as infrared thermometers, and laser ignition systems, turn on high-speed cameras and other diagnostic equipment, turn on plasma generators, turn on laser igniters to ignite metal particles, and after combustion is completed, wait for the experimental device to cool down, first open the exhaust valve to release the pressure, open the first connection part 4 flange to take out the combustion products, perform electron microscope scanning analysis, energy spectrum analysis, etc. on the combustion products, and further obtain more detailed information such as the morphological characteristics and composition structure of the combustion products, thereby achieving the experimental purpose.

[0068] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0069] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A multi-mode combustion experimental device for plasma-assisted combustion, characterized in that: It includes laser incident components, combustion chamber and material supply components; The laser incident component is arranged at the top of the combustion chamber, and is used to introduce laser into the combustion chamber for ignition; The combustion chamber is composed of an end surface connection part and a combustion cavity. The outer wall of the combustion cavity is provided with two symmetrical observation windows and a conduction window, and the vertical surface of the conduction window is perpendicular to the vertical surface of the observation window. The combustion cavity is a hollow cylindrical cavity, and the length ratio of the bottom diameter to the height is 1:

3. The conduction window is arranged close to the bottom of the combustion cavity, and the plane where the conduction window is located is taken as the front, and the front projection area of ​​the conduction window is 15%-18% of the front projection area of ​​the combustion cavity. The material supply component is arranged at the bottom of the combustion chamber, and is used for introducing reactants into the combustion chamber; the material supply component is a water-gas balance box or a feed tray, and the water-gas balance box can generate water vapor to create a water vapor environment required for the experiment.

2. The multi-mode combustion experimental device for plasma-assisted combustion according to claim 1, characterized in that: Taking the plane where the conduction window is located as the front, the front projection shape of the conduction window is a rectangle, and the central axis of the rectangle coincides with the central axis of the front projection of the combustion chamber.

3. The multi-mode combustion experimental device for plasma-assisted combustion according to claim 2, characterized in that: The length ratio of the base to the height of the rectangle is 1:2, and the upper base of the rectangle is set at 1 / 2 of the height of the combustion chamber, and the lower base is set between 1 / 4 and 1 / 6 of the height of the combustion chamber.

4. The multi-mode combustion experimental device for plasma-assisted combustion according to claim 1, characterized in that: Each of the observation windows is composed of a number of independent windows that are evenly distributed along the axial direction.

5. The multi-mode combustion experimental device for plasma-assisted combustion according to claim 4, characterized in that: The length of the independent window cannot exceed half the wavelength of the microwave frequency.

6. The multi-mode combustion experimental device for plasma-assisted combustion according to claim 1, characterized in that: The outer wall of the combustion chamber is also provided with a plurality of gas transport holes and a pressure detection hole.

7. The multi-mode combustion experimental device for plasma-assisted combustion according to claim 6, characterized in that: Four gas delivery holes are provided, wherein two gas delivery holes are provided near the top of the combustion chamber, and two gas delivery holes are provided near the bottom of the combustion chamber.

8. The multi-mode combustion experimental device for plasma-assisted combustion according to claim 1, characterized in that: The end surface connection part includes a first connection part and a second connection part, the laser incident component is connected and fixed to the first connection part, and the material supply component is connected and fixed to the second connection part.

9. The multi-mode combustion experimental device for plasma-assisted combustion according to claim 1, characterized in that: The laser incident component comprises an incident window end cover, a glass seal and a sealing flange which are connected in sequence, and the sealing flange is communicated with the first connecting portion.

10. The multi-mode combustion experimental device for plasma-assisted combustion according to claim 8, characterized in that: The water-gas balance box includes a number of heating components and a water tank; The top of the water tank is communicated with the second connection part, and a propulsion boss is arranged at the bottom of the water tank. A through hole is arranged on the top surface of the propulsion boss, and the propulsion boss is used to connect with an external propulsion device to transport reactants.

Images