Engine with interval air intake of inner column

Abstract

The engine comprises a shell and the inner column, one end of an annular channel is provided with at least one powder inlet channel, and the other end of the annular channel is open; an oxidant inlet is formed in one end, close to the powder inlet channel, of the inner column; the interior of the inner column is sequentially divided into an oxidant gas collection cavity, an expansion cavity and an oxidant injection cavity in the direction from the oxidant gas inlet to the closed end of the inner column; the inner column is located on the outer wall of the expansion cavity, and a circle of oxidant injection channels are uniformly arranged in the circumferential direction of the inner column and used for conveying an oxidant from the expansion cavity to the annular channel for communication; the inner column is located on the outer wall of the oxidizing agent injection cavity, and multiple circles of rotational flow injection holes are uniformly formed in the circumferential direction of the inner column and used for conveying an oxidizing agent from the oxidizing agent injection cavity to the annular channel for communication; a space for mixed combustion of powder fuel and an oxidizing agent is provided in the annular combustion chamber. The problems that an existing rotary detonation engine is single in injection structure, and propellant mixing is not uniform are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of aerospace engine structural design, and particularly relates to an engine with internal column spaced air intake.

Background Art

[0002] Almost all traditional piston, turbine, and rocket engine power propulsion devices are based on the deflagration combustion mode. The deflagration mode burns in an approximately isobaric manner, with a gentle chemical reaction and a relatively low flame propagation speed, generally on the order of meters per second. With the continuous development and improvement of engines, all aspects of traditional deflagration mode engines are relatively mature. To significantly improve the propulsion efficiency and performance of engines, it is necessary to explore new forms of combustion and thermodynamic cycle modes and develop new propulsion technologies with higher performance.

[0003] Detonation (also known as detonation shock) is a combustion process in which a shock wave induces a flame and uses the dual effects of combustion reaction and shock wave for stable propagation. During the detonation process, the energy released by combustion maintains the intensity of the shock wave advancing into the combustible, and at the same time, the shock wave compresses the combustible to generate high-temperature and high-pressure working medium for rapid chemical reaction, releasing a large amount of heat. Compared with deflagration, detonation is approximately isochoric combustion, with a propagation speed on the order of kilometers per second, and has the advantages of low entropy increase, self-pressurization characteristics, and high thermal cycle efficiency. Powder has the characteristics of high volume energy density, high transportation safety, and low price, which makes it have unique advantages as a fuel for engines.

[0004] The rotating detonation powder engine (PRDE) based on the detonation combustion mode has higher combustion efficiency, a fast heat release rate, and a more stable combustion process. For a rotating detonation powder engine, its combustion chamber generally adopts a coaxial ring structure, uses high-energy metal or non-metal powder as fuel, fluidizes the powder and transports it into the combustion chamber for mixing with the oxidizer. When the mixture fills the annular combustion chamber, a pre-detonation wave is injected tangentially through a pre-detonation tube to initiate the mixture, and the generated detonation wave continuously and stably rotates around the axis in the combustion chamber. The detonation products are ejected at high speed from the outlet end under the combined action of oblique shock waves and expansion waves and generate thrust. The rotating detonation engine has outstanding advantages such as only requiring one ignition initiation, fast combustion speed, easy control, self-compression, small volume, simple structure, multiple extinguishing and ignition capabilities, high thermal efficiency, large specific impulse, large thrust adjustment range, high thrust-to-weight ratio, and vector adjustment ability, and is an important development direction for future aerospace power.

[0005] Compared with traditional isobaric combustion powder engines, the PRDE needs to maintain a stable detonation state to enable the engine to operate continuously and stably. Compared with other types of powder engines and gas-phase rotating detonation engines, the PRDE puts forward higher requirements for the mixing effect of powder fuel and oxidizer. Therefore, there is an urgent need for a jet structure with good propellant mixing characteristics.

Summary of the Invention

[0006] The object of the present invention is to provide an engine with internal column spaced air intake to solve the problems of single injection structure and uneven propellant mixing in existing rotating detonation engines.

[0007] The present invention adopts the following technical solutions: An engine with internal column spaced air intake includes a coaxially sleeved housing and an internal column. Both the housing and the internal column are hollow cylindrical bodies, and the gap between the housing and the internal column forms an annular channel; at least one powder inlet channel is provided at one end of the annular channel, and the other end is open; an oxidant inlet is provided at one end of the internal column close to the powder inlet channel, and the other end is closed;

[0008] Inside the internal column, along the direction from the oxidant inlet to its closed end, it is sequentially divided into an oxidant gas collection chamber, a diffusion chamber, and an oxidant injection chamber;

[0009] Among them, the outer wall diameters of the oxidant gas collection chamber and the oxidant injection chamber are the same, and the outer wall diameter of the diffusion chamber is larger than that of the oxidant gas collection chamber; on the outer wall of the internal column located in the diffusion chamber, a circle of oxidant injection channels is evenly arranged around its circumference. The oxidant injection channels are inclined and communicate with the annular channel for transporting the oxidant from the diffusion chamber to the annular channel; on the outer wall of the internal column located in the oxidant injection chamber, multiple circles of swirl injection holes are evenly arranged around its circumference for transporting the oxidant from the oxidant injection chamber to the annular channel.

[0010] According to the positions corresponding to the oxidant gas collection chamber, the diffusion chamber, and the oxidant injection chamber, the annular channel is sequentially divided into a powder fuel chamber, a contraction-expansion ring gap, and an annular combustion chamber; among them, the internal column is used to accommodate the oxidant and inject the oxidant into the annular combustion chamber through each swirl injection hole; the powder fuel chamber is used to accommodate the powder fuel; the contraction-expansion ring gap is used to exert an extrusion and acceleration effect on the powder; the annular combustion chamber is used to provide a space for the mixing and combustion of the powder fuel and the oxidant.

[0011] Further, on each annular cross-section of the internal column where a circle of swirl injection holes is provided, the central axis of each swirl injection hole is obtained by parallel offset from any center line of the annular cross-section, so that a swirl effect is formed inside the internal column when the oxidant is introduced through each swirl injection hole.

[0012] Further, at least three high-frequency piezoelectric pressure sensors are arranged around the position of the annular combustion chamber on the housing, and at least three high-frequency piezoelectric pressure sensors are evenly arranged along the axial direction on the outer wall of the housing.

[0013] Further, at least three piezoresistive pressure sensors are evenly arranged on the outer wall of the housing.

[0014] Further, a nozzle connection port is provided at the closed end of the internal column.

[0015] Further, a pre-detonation tube is provided at a position on the outer wall of the housing corresponding to the annular combustion chamber for igniting the mixture in the annular combustion chamber.

[0016] Further, there are three powder inlet channels arranged in an annular array about the central axis of the inner column.

[0017] The beneficial effects of the present invention are as follows: a rotating detonation powder engine with spaced air intakes in the inner column, wherein the powder fuel enters the annular combustion chamber through a converging-diverging annular gap under the entrainment of the fluidizing gas, and the oxidizer enters the annular combustion chamber twice through the oxidizer injection channels inclined at 45° in the gas collecting chamber and the swirling injection holes spaced on the outer wall of the inner column, forming a double mixing mechanism of "premixing first and then enhanced mixing", which meets the high-efficiency combustion requirements of the powder fuel, effectively solves the problem of uneven mixing of traditional RDE propellants, and has the characteristics of simple structure, uniform mixing, high detonation efficiency, and stable detonation wave propagation, significantly improving the mixing uniformity of the powder fuel and the oxidizer and enhancing the stability of detonation wave propagation.

[0018] In the design of traditional rotating detonation engines, the injection holes are usually symmetrically distributed circumferentially, and the central axis of the injection holes coincides with the center line of the annular cross-section. This symmetric layout is considered to simplify the flow field distribution and reduce the processing difficulty. Designers often give priority to structural symmetry to balance the force and flow uniformity. The present invention adopts the "eccentric" concept contrary to the conventional design concept. The eccentric hole design breaks through the traditional symmetric injection thinking mode, and through the coupling of geometric offset and dynamic flow field, realizes the coordinated optimization of the swirling intensity and mixing efficiency.

[0019] The asymmetric flow field generated by the eccentric injection can break the laminar separation zone that may be formed by the traditional symmetric injection, reducing the local lean combustion or rich combustion phenomenon. In the rotating detonation engine of powder fuel, the swirling enhances the turbulent mixing, shortens the combustion reaction time, enables the powder fuel to release energy more quickly under high temperature and high pressure, and significantly improves the detonation efficiency and specific impulse. The design of the eccentric hole significantly improves the mixing uniformity, detonation stability and energy release efficiency, and becomes the key innovation point to solve the bottleneck of the traditional RDE configuration.

Description of the Drawings

[0020] Figure 1 It is a three-dimensional structure schematic diagram of an engine with spaced air intakes in the inner column of the present invention;

[0021] Figure 2 It is a front view of an engine with spaced air intakes in the inner column of the present invention;

[0022] Figure 3 It is for Figure 2 the schematic diagram of the A-A cross-section of

[0023] Figure 4 It is forFigure 2 Schematic diagram of the B-B cross-section;

[0024] Figure 5 is Figure 3 Schematic diagram of the H-H cross-section.

[0025] Wherein, 1. housing, 2. inner column, 3. pre-detonation tube welding joint, 4-1. first high-frequency piezoelectric pressure sensor interface, 4-2. second high-frequency piezoelectric pressure sensor interface, 4-3. third high-frequency piezoelectric pressure sensor interface, 4-4. fourth high-frequency piezoelectric pressure sensor interface, 4-5. fifth high-frequency piezoelectric pressure sensor interface, 5-1. first piezoresistive pressure sensor interface, 5-2. second piezoresistive pressure sensor interface, 5-3. third piezoresistive pressure sensor interface, 6. powder fuel chamber, 7. powder inlet channel, 8. oxidant collecting chamber, 9. oxidant inlet, 10. swirl injection hole, 11. annular combustion chamber, 12. expansion chamber, 13. oxidant injection chamber, 14. contraction-expansion annular gap, 15. nozzle connection port, 16. inner column flange, 17. front housing flange, 18. rear housing flange, 19. oxidant injection channel.

Specific embodiments

[0026] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0027] The present invention provides an engine with interval air intake of the inner column, as Figures 1 to 5 shown, including a coaxially sleeved housing 1 and an inner column 2. Both the housing 1 and the inner column 2 are hollow cylindrical bodies. The gap between the housing 1 and the inner column 2 forms an annular channel; one end of the annular channel is provided with a powder inlet channel 7, and the other end is open; one end of the inner column 2 close to the powder inlet channel 7 is provided with an oxidant inlet 9, and the other end is closed.

[0028] Inside the inner column 2, along the direction from the oxidant inlet 9 to its closed end, it is sequentially divided into an oxidant collecting chamber 8, an expansion chamber 12, and an oxidant injection chamber 13;

[0029] Wherein, the outer wall diameters of the oxidant collecting chamber 8 and the oxidant injection chamber 13 are the same, and the outer wall diameter of the expansion chamber 12 is larger than the outer wall diameter of the oxidant collecting chamber 8; on the outer wall of the inner column 2 where the expansion chamber 12 is located, a circle of oxidant injection channels 19 is evenly arranged around its circumference. The oxidant injection channels 19 are inclined and communicate with the annular channel for transporting the oxidant from the expansion chamber 12 to the annular channel; on the outer wall of the inner column 2 where the oxidant injection chamber 13 is located, multiple circles of swirl injection holes 10 are evenly arranged around its circumference for transporting the oxidant from the oxidant injection chamber 13 to the annular channel.

[0030] According to the positions corresponding to the oxidizer gas collection chamber 8, the expansion chamber 12, and the oxidizer injection chamber 13, the annular channel is sequentially divided into a powdered fuel chamber 6, a converging-diverging annular slit 14, and an annular combustion chamber 11. Among them, the inner column 2 is used to accommodate the oxidizer and inject the oxidizer into the annular combustion chamber 11 through each swirl injection hole 10. The powdered fuel chamber 6 is used to accommodate the powdered fuel. The converging-diverging annular slit 14 is used to exert a squeezing effect on the powder so that the powdered fuel accelerates into the annular combustion chamber 11, and the annular combustion chamber 11 is used to mix the powdered fuel and the oxidizer.

[0031] In some embodiments, on each annular cross-section where a circle of swirl injection holes 10 is arranged on the inner column 2, the central axis of each swirl injection hole 10 is obtained by parallel offset from any center line of the annular cross-section, so that a swirl effect is formed inside the inner column 2 when the oxidizer is introduced through each swirl injection hole 10. The offset distance is determined according to factors such as the size of the inner column 2, the desired swirl intensity, and the properties of the introduced oxidizer, etc., to achieve the best swirl effect.

[0032] In some embodiments, at least three high-frequency piezoelectric pressure sensors are arranged around the position corresponding to the annular combustion chamber 11 on the housing 1, and on the outer wall of the housing 1, at least three high-frequency piezoelectric pressure sensors are evenly arranged along its axis direction, which are used to measure the pressure of the rotating detonation wave, so as to obtain the propagation characteristics of the rotating detonation wave.

[0033] In some embodiments, at least three piezoresistive pressure sensors are evenly arranged on the outer wall of the housing 1, which are used to measure the pressure inside the housing 1.

[0034] In some embodiments, a nozzle connection port 15 is arranged at the closed end of the inner column 2, which is used to connect a plug nozzle.

[0035] In some embodiments, a pre-detonation tube is arranged at the position on the outer wall of the housing 1 corresponding to the annular combustion chamber 11, which is used to ignite the mixture in the annular combustion chamber 11.

[0036] In some embodiments, there are three powder inlet channels 7 arranged in an annular array with respect to the central axis of the inner column 2.

[0037] The usage method of an engine with internal column spaced air intake of the present invention is as follows:

[0038] The powdered fuel is carried by the fluidizing gas through the powdered fuel chamber 6 and the convergent-divergent annular slit 14 and enters the annular combustion chamber 11; the oxidant passes through the oxidant gas collecting chamber 8 and then enters the annular combustion chamber 11 through the oxidant injection channel 19 arranged at a 45° inclination. This stage is the premixing of the powdered fuel and the oxidant; then the oxidant continues to move towards the oxidant injection chamber 13 and enters the annular combustion chamber 11 again through the swirling injection holes 10 arranged at intervals on the outer wall of the inner column 2. This stage is the enhanced mixing of the powdered fuel and the oxidant.

[0039] Finally, the powdered fuel in the annular combustion chamber 11 is ignited through the pre-detonation tube, and then the pre-detonation wave detonates the uniformly mixed powdered fuel and oxidant in the annular combustion chamber 11, generating a stable detonation wave that continuously and stably rotates around the axis in the combustion chamber. The detonation products are ejected at high speed from the outlet end under the combined action of the oblique shock wave and the expansion wave and generate a continuous and stable axial thrust.

[0040] In summary, the structural setting of the present invention is novel, providing a dual mixing mechanism of "premixing first and then enhanced mixing", which meets the high-efficiency combustion requirements of powdered fuel, effectively solves the problem of uneven mixing of traditional RDE propellants, and has the characteristics of simple structure, uniform mixing, high detonation efficiency, and stable detonation wave propagation, significantly improving the mixing uniformity of the powdered fuel and the oxidant and enhancing the stability of detonation wave propagation.

[0041] Embodiment

[0042] Refer to Figures 1 to 3 , a rotating detonation powdered engine with internal column spaced air intake, comprising a housing 1 and an internal column 2. A pre-detonation tube welding interface 3 is arranged on the housing 1, and five high-frequency piezoelectric pressure sensors are respectively installed at the first high-frequency piezoelectric pressure sensor interface 4-1, the second high-frequency piezoelectric pressure sensor interface 4-2, the third high-frequency piezoelectric pressure sensor interface 4-3, the fourth high-frequency piezoelectric pressure sensor interface 4-4, and the fifth high-frequency piezoelectric pressure sensor interface 4-5; three piezoresistive pressure sensors are also arranged and respectively installed at the first piezoresistive pressure sensor interface 5-1, the second piezoresistive pressure sensor interface 5-2, and the third piezoresistive pressure sensor interface 5-3.

[0043] The housing 1 and the internal column 2 are connected by means of the internal column flange 16 and the front housing flange 17. Among them, the internal column flange 16 and the front housing flange 17 are evenly provided with 16 holes with a diameter of 9 mm along the circumference for flange bolt connection. The annular chamber 11 between the housing 1 and the internal column 2 forms the annular combustion chamber 11 of the rotating detonation engine. The outer diameter of the annular combustion chamber 11 is 110 mm, the inner diameter is 82 mm, and the length is 180 mm.

[0044] A pre-detonation tube welding interface 3 is formed by a tangential opening on the housing 1, with a diameter of 4 mm, and a pre-detonation tube can be welded.

[0045] Five high-frequency piezoelectric pressure sensor interfaces and three piezoresistive pressure sensor interfaces are formed by diametrically opening on the housing 1, with a hole diameter of 5 mm for welding the pressure measuring seats of the corresponding sensors.

[0046] Among them, the first high-frequency piezoelectric pressure sensor interface 4-1, the second high-frequency piezoelectric pressure sensor interface 4-2, and the third high-frequency piezoelectric pressure sensor interface 4-3 are evenly spaced circumferentially, with an included angle of 120°.

[0047] The first high-frequency piezoelectric pressure sensor interface 4-1, the fourth high-frequency piezoelectric pressure sensor interface 4-4, and the fifth high-frequency piezoelectric pressure sensor interface 4-5 are axially distributed with a spacing of 30 mm. The high-frequency piezoelectric pressure sensors are used to measure the instantaneous propagation speed of the detonation wave.

[0048] The first piezoresistive pressure sensor interface 5-1, the second piezoresistive pressure sensor interface 5-2, and the third piezoresistive pressure sensor interface 5-3 are axially distributed with a spacing of 30 mm. The piezoresistive pressure sensors are used to measure the average pressure in the combustion chamber.

[0049] During the working process, the powder feeding channel 7 is connected to the powder fluidizing gas. The powdered fuel is carried by the fluidizing gas and passes through the powdered fuel chamber 6 and enters the annular combustion chamber 11 through the converging-diverging annular slit. The powder feeding channel 7 has a total of three powder feeding holes, which are evenly distributed along the circumference with a diameter of 98 mm to achieve uniform filling of the powdered fuel. The oxidizer inlet 9 is connected to the oxygen-rich air source, and oxygen-rich air is introduced into the oxidizer gas collecting chamber 8 through the oxidizer inlet 9. The oxygen-rich air first passes through the 45° inclined swirl injection holes 10 in the oxidizer gas collecting chamber 8 to mix with the powdered fuel and enter the annular combustion chamber 11. These inclined holes are 1 mm small holes evenly distributed along the circumference; secondly, the oxygen-rich air enters the annular combustion chamber 11 in a swirling manner through the swirl injection holes 10 axially spaced 30 mm apart on the inner column 2 and mixes with the powdered fuel again to form a "pre-mixing first and then enhanced mixing" dual mixing mechanism, thereby effectively improving the mixing characteristics of the propellant and enhancing the detonation efficiency and the propagation stability of the detonation wave of the rotating detonation powder engine. Among them, the swirl injection holes 10 are 1 mm swirling small holes evenly distributed along the circumference.

[0050] The rear flange 18 of the housing can be used to connect the airtight detection component to detect the airtightness of the engine system before ignition; the engine is provided with a nozzle connection port 15, which can be connected to the corresponding plug nozzle.

Claims

1. An engine with inner column interval intake, characterized in that: The invention comprises a coaxially mounted shell (1) and an inner column (2), wherein the shell (1) and the inner column (2) are both hollow cylindrical bodies, and the gap between the shell (1) and the inner column (2) forms an annular channel; at least one powder inlet channel (7) is provided at one end of the annular channel, and the other end is open; an oxidant air inlet (9) is provided at one end of the inner column (2) close to the powder inlet channel (7), and the other end is closed; The interior of the inner column (2) is divided into an oxidant gas collecting chamber (8), an expansion chamber (12) and an oxidant injection chamber (13) in sequence along the direction from the oxidant gas inlet (9) to its closed end; The outer wall diameters of the oxidant collecting chamber (8) and the oxidant injection chamber (13) are the same, and the outer wall diameter of the expansion chamber (12) is larger than the outer wall diameter of the oxidant collecting chamber (8); on the outer wall of the expansion chamber (12) located on the inner column (2), a circle of oxidant injection channels (19) are evenly arranged around the circumference thereof, and the oxidant injection channels (19) are inclinedly arranged and connected to the annular channel, and are used to transport the oxidant from the expansion chamber (12) to the annular channel for communication; on the outer wall of the oxidant injection chamber (13) located on the inner column (2), a plurality of circles of swirl injection holes (10) are evenly arranged around the circumference thereof, and are used to transport the oxidant from the oxidant injection chamber (13) to the annular channel for communication; According to the positions corresponding to the oxidant collecting chamber (8), the expansion chamber (12) and the oxidant injection chamber (13), the annular channel is divided into a powder fuel chamber (6), a contraction-expansion annular gap (14) and an annular combustion chamber (11) in sequence; wherein the inner column (2) is used to accommodate the oxidant and inject the oxidant into the annular combustion chamber (11) through each swirl injection hole (10); the powder fuel chamber (6) is used to accommodate the powder fuel; the contraction-expansion annular gap (14) is used to produce an extrusion acceleration effect on the powder; and the annular combustion chamber (11) is used to provide a space for the mixed combustion of the powder fuel and the oxidant.

2. An engine with inner column spaced intake as claimed in claim 1, characterized in that: On each annular cross-section of a circle of swirl injection holes (10) arranged on the inner column (2), the central axis of each swirl injection hole (10) is obtained by being offset in parallel with any center line of the annular cross-section, so that when the oxidant is introduced through each swirl injection hole (10), a swirl effect is formed inside the inner column (2).

3. An engine with inner column spaced intake as claimed in claim 1 or 2, characterized in that: At least three high-frequency piezoelectric pressure sensors (4) are arranged around the position of the shell (1) corresponding to the annular combustion chamber (11), and at least three high-frequency piezoelectric pressure sensors (4) are evenly arranged on the outer wall of the shell (1) along its axial direction.

4. An engine with inner column spaced intake as claimed in claim 1 or 2, characterized in that: At least three piezoresistive pressure sensors (5) are evenly arranged on the outer wall of the housing (1).

5. An engine with inner column spaced intake as claimed in claim 1 or 2, characterized in that: A nozzle connection port (15) is provided at the closed end of the inner column (2).

6. An engine with inner column spaced intake as claimed in claim 1 or 2, characterized in that: A pre-detonation tube is provided at a position on the outer wall of the shell (1) corresponding to the annular combustion chamber (11), and is used to ignite the mixture in the annular combustion chamber (11).

7. An engine with inner column spaced intake as claimed in claim 1 or 2, characterized in that: The powder inlet channels (7) are three arranged in a circular array about the central axis of the inner column (2).

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