Pulsation jet engine with double-layer combustion chamber

Abstract

The invention discloses a pulsating jet engine with a double-layer combustion chamber. The pulsating jet engine is composed of the double-layer combustion chamber, an air inlet channel, a tail pipe, an oil nozzle and the like. The engine combustion chamber is of a double-layer structure, the inner-layer wall face is the main structure of the engine combustion chamber, the size of the engine combustion chamber is controlled, and main combustion temperature of an engine is borne. And a certain space is formed between the outer-layer wall surface and the inner-layer wall surface for isolation. And the middle gap can be vacuumized and can also be filled with a non-metallic material with high temperature resistance and low thermal conductivity. The pulsating engine with the double-layer combustion chamber has the advantages that in the starting and working process of the engine, the heat loss of the wall face of the engine can be reduced, the temperature of fuel gas in the combustion chamber can be increased, the propelling efficiency of the engine can be improved, the working environment boundary of the engine can be widened, and the infrared stealth performance can be effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of aircraft technology, specifically relating to a pulse jet engine with a double-layer combustion chamber. Background Technology

[0002] Pulsed jet engines are a type of jet engine power unit. Currently, publicly available pulsed jet engines, both domestically and internationally, primarily employ valves or diaphragms to control the intake air into the combustion chamber. Valve-based structures, with their moving parts like valves, significantly reduce engine lifespan and reliability, and lack the ability for long-term storage and maintenance-free operation. Valveless pulsed jet engines, in their structural design, generally only consider whether the engine can start and operate normally, and whether the structural dimensions are reasonable, without in-depth research into their performance and thermal efficiency. Pulsed jet engines rely on the pressure changes of their own pulsed combustion to perform intake, compression, and exhaust cycles. However, the internal temperature of the engine combustion chamber reaches as high as 2000K, and the combustion chamber wall temperature is close to 1100K. Due to the high wall temperature, the engine experiences significant heat loss, which not only restricts the improvement of thermal efficiency but also affects the reliability of the engine's pulsed combustion cycle. Therefore, how to effectively and rapidly improve the reliability and performance of pulsed engines is a key aspect of pulsed engine research and a problem that urgently needs to be solved in engineering applications.

[0003] The dual-combustion chamber pulse jet engine is a novel engine structure currently under research. Its working principle is entirely based on the combustion principle and characteristics of pulse jet engines. It utilizes a structure with different intake and exhaust pipe lengths to generate pulsed combustion in the combustion chamber, producing thrust by expelling high-speed hot exhaust gas through the exhaust pipe. Structurally, the combustion chamber employs a dual-layer design, while the remaining structure is similar to that of a conventional pulse jet engine.

[0004] Currently available reports do not mention a pulse jet engine with a dual-combustion chamber. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention provides a pulsed jet engine with a double-layered combustion chamber, comprising a double-layered combustion chamber, an air intake, a tailpipe, and fuel injectors. The engine combustion chamber of this invention employs a double-layered structure. The inner wall forms the main structure of the combustion chamber, controlling its volume and bearing the engine's primary combustion temperatures. A certain spatial isolation exists between the outer and inner walls. This gap can be evacuated to a vacuum or filled with a high-temperature resistant, low-thermal-conductivity non-metallic material. The advantages of this pulsed jet engine with a double-layered combustion chamber are that during engine start-up and operation, it reduces heat loss from the engine walls, increases the internal combustion gas temperature, improves engine propulsion efficiency, expands the engine's operating environment boundaries, and effectively enhances infrared stealth performance.

[0006] The technical solution adopted by this invention to solve its technical problem is as follows: A pulse jet engine with a dual-combustion chamber includes a dual-combustion chamber, a fuel injector, an air inlet, and a tailpipe; the dual-combustion chamber includes an inner wall, an outer wall, and a middle layer. The rear end face of the double-layer combustion chamber is connected to the air intake and tailpipe; the air intake and tailpipe outlets both face the rear of the engine. The fuel injector is located in a double-layer combustion chamber; The intermediate layer is located between the inner wall and the outer wall. The intermediate layer is either vacuum-sealed or filled with non-metallic material.

[0007] Preferably, the non-metallic material is a non-metallic material that is resistant to high temperatures and has a low thermal conductivity.

[0008] Preferably, the high-temperature resistant, low-thermal-conductivity non-metallic material is mullite needle-punched felt.

[0009] Preferably, the mullite needle-punched felt has a thermal conductivity of ≤0.15W / (mk) at room temperature, a thermal conductivity of ≤0.38W / (mk) at 600℃, and a high temperature resistance of over 1300℃.

[0010] Preferably, the high-temperature resistant, low-thermal-conductivity non-metallic material is a zirconium-containing ceramic fiber blanket.

[0011] Preferably, the thickness of the intermediate layer is 2-5 mm.

[0012] Preferably, the pulse jet engine further includes an ignition device; the ignition device can be installed at any position on the inner wall of the double-layer combustion chamber.

[0013] Preferably, the cross-section of the double-layer combustion chamber is circular.

[0014] Preferably, the cross-section of the double-layer combustion chamber is elliptical.

[0015] The beneficial effects of this invention are as follows: This invention utilizes a double-layer combustion chamber structure to effectively solve the heat loss problem caused by high-temperature heat conduction and radiation during engine operation. It increases the internal combustion gas temperature (inner wall temperature increases from 800℃ to 1200℃), improving the reliability of stable pulsed combustion (higher gas temperature facilitates ignition and combustion at the beginning of the next cycle in pulsed combustion), improving engine propulsion efficiency (increased thrust), effectively expanding the starting and operating flow rate boundaries (from the original 3g / s-5g / s to 2.5g / s-6g / s), and significantly increasing the operating altitude (from the original 3000m to 4000m). The engine of this invention features a simple structure, convenient use and maintenance, high overload resistance, long storage, and maintenance-free operation. Furthermore, its simple structural design and high reliability provide broader power for aircraft, expanding its application range. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the engine structure of the present invention.

[0017] Figure 2 This is a schematic diagram of the cross-section of the circular combustion chamber according to an embodiment of the present invention.

[0018] Figure 3 This is a schematic diagram of the cross-section of the elliptical combustion chamber according to an embodiment of the present invention.

[0019] Attached reference numerals: 1-Double-layer combustion chamber, 2-Fuel injector, 3-Air inlet, 4-Tailpipe, 5-Inner wall, 6-Outer wall, 7-Intermediate layer. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] This invention, based on existing pulsed jet engines, makes reasonable modifications to the combustion chamber structure. Specifically, it maintains the same structural dimensions of the main combustion chamber, ensuring reliable engine operation, by adding a wall structure to the outer wall of the combustion chamber. A certain gap is left between the inner and outer wall layers; this gap can be designed as a vacuum or filled with heat-insulating material. By improving the single-layer structure of the combustion chamber to a double-layer structure, heat loss during engine start-up and operation is effectively reduced, improving engine performance and reliability.

[0022] A pulse jet engine structure with a double-layer combustion chamber includes: a double-layer combustion chamber, a fuel injector, an air inlet, and a tailpipe; the double-layer combustion chamber consists of an inner wall, an outer wall, and a middle layer.

[0023] The double-layer combustion chamber is the main component of the engine. The inner wall of the double-layer combustion chamber forms the main body of the combustion chamber and is the primary cavity for fuel-air mixture combustion. Its structural dimensions directly determine the volume of the combustion chamber and also the engine's operating frequency. The outer and inner walls of the combustion chamber are spaced apart by a certain distance, forming an intermediate layer.

[0024] The intermediate layer can be designed as a vacuum or filled with a non-metallic material that is resistant to high temperatures and has low thermal conductivity.

[0025] The outer wall can be designed to have a different structural shape than the inner wall, and the gap between the outer and inner walls can be unequal, with a distance of 2-5mm.

[0026] The rear end face of the double-layer combustion chamber connects to the air intake and tailpipe. The outlet directions of both the air intake and tailpipe face the rear of the engine, which helps to increase thrust during operation.

[0027] For a pulse jet engine with a double combustion chamber to operate normally, it also needs an ignition device. The ignition device can be installed at any position on the inner wall of the combustion chamber of the pulse engine. The output of the ignition device should have a certain temperature and energy to ignite the fuel-air mixture in the combustion chamber.

[0028] Example: Reference Figure 1 This invention designs a small pulse jet engine with a diameter of 80mm, and the layout of its dual-layer combustion chamber, air intake, and tailpipe is shown in the figure. (Refer to...) Figure 2 , Figure 3 The double-layer combustion chamber can be designed with a concentric circle outer structure based on the basic structure of the combustion chamber, or it can be designed with an irregular structure, such as an elliptical structure, depending on the allowable space of the aircraft structure, that is, the gap interval is a variable form.

[0029] A double-layer combustion chamber is generally a double-layer metal structure. The middle layer can be filled with a non-metallic, high-temperature resistant, low-thermal-conductivity insulation material, or designed as a vacuum, thereby reducing the thermal conductivity of the inner and outer walls and increasing the internal temperature of the combustion chamber.

[0030] The double-layer combustion chamber can also be designed with an inner wall made of metal and an outer wall and middle layer made of non-metallic material.

[0031] The dual-chamber pulse jet engine of the present invention can effectively reduce the heat loss of engine combustion, improve engine performance, expand the engine working boundary, and increase the engine working height by simply optimizing the combustion chamber structure.

[0032] Mullite needle-punched felt can be used as insulation material, with a thermal conductivity of ≤0.15W / (mk) at room temperature, ≤0.38W / (mk) at 600℃, and a temperature resistance of over 1300℃. Zirconium-containing ceramic fiber blankets can also be selected as insulation materials.

Claims

1. A pulse jet engine with a dual-chamber combustion chamber, characterized in that, It includes a double-layer combustion chamber, fuel injectors, air intake, and tailpipe; the double-layer combustion chamber includes an inner wall, an outer wall, and a middle layer; The rear end face of the double-layer combustion chamber is connected to the air intake and tailpipe; the air intake and tailpipe outlets both face the rear of the engine. The fuel injector is located in a double-layer combustion chamber; The intermediate layer is located between the inner wall and the outer wall. The intermediate layer is either vacuum-sealed or filled with non-metallic material.

2. The pulse jet engine with a double-layer combustion chamber according to claim 1, characterized in that, The non-metallic material is a non-metallic material that is resistant to high temperatures and has a low thermal conductivity.

3. A pulse jet engine with a double-layer combustion chamber according to claim 2, characterized in that, The high-temperature resistant, low-thermal-conductivity non-metallic material is mullite needle-punched felt.

4. A pulse jet engine with a double-layer combustion chamber according to claim 3, characterized in that, The mullite needle-punched felt has a thermal conductivity of ≤0.15W / (mk) at room temperature, ≤0.38W / (mk) at 600℃, and can withstand high temperatures of over 1300℃.

5. A pulse jet engine with a double-layer combustion chamber according to claim 2, characterized in that, The high-temperature resistant, low-thermal-conductivity non-metallic material is a zirconium-containing ceramic fiber blanket.

6. A pulse jet engine with a double-layer combustion chamber according to claim 1, characterized in that, The thickness of the intermediate layer is 2-5 mm.

7. A pulse jet engine with a double-layer combustion chamber according to claim 1, characterized in that, The pulse jet engine also includes an ignition device; the ignition device can be installed at any position on the inner wall of the double-layer combustion chamber.

8. A pulse jet engine with a double-layer combustion chamber according to claim 1, characterized in that, The cross-section of the double-layer combustion chamber is circular.

9. A pulse jet engine with a double-layer combustion chamber according to claim 1, characterized in that, The cross-section of the double-layer combustion chamber is elliptical.

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