阅读说明：本技术 一种中小推力火箭发动机高效稳定燃烧喷注器 (High-efficiency stable combustion injector of medium-small thrust rocket engine ) 是由 周思引 聂万胜 杨云帆 杨嘉煊 刘翔 闫康 张皓涵 于 2021-07-26 设计创作，主要内容包括：本发明公开了一种中小推力火箭发动机高效稳定燃烧喷注器,包括喷注面板、离心式等离子喷嘴和高压电源；离心式等离子喷嘴呈同心圆式均布设在喷注面板上,喷注面板为绝缘的单层喷注面板或双层喷注面板,能良好兼容多个等离子体喷嘴。绝缘外喷嘴的喷射端内壁面设有扩张角α；内、外喷嘴之间设有氧化剂通道；金属内喷嘴接地,且具有缩进距离L；金属环套设在外喷嘴喷射的外壁,且长度大于L,并连接高压电源；通过调整L和α,能调节雾化效果和燃烧效率。本发明通过将非平衡等离子体辅助燃烧技术与火箭发动机喷注器设计相结合,达到缩短甲烷等燃料的点火延迟,拓宽点火极限,扩散火焰更快达到稳定状态的效果,实现快速点火、高效稳定燃烧。(The invention discloses a high-efficiency stable combustion injector of a medium-small thrust rocket engine, which comprises an injection panel, a centrifugal plasma nozzle and a high-voltage power supply, wherein the injection panel is connected with the centrifugal plasma nozzle; the centrifugal plasma nozzles are uniformly distributed on the injection panel in a concentric circle manner, and the injection panel is an insulated single-layer injection panel or a double-layer injection panel and can be well compatible with a plurality of plasma nozzles. An expansion angle alpha is arranged on the inner wall surface of the injection end of the insulating outer nozzle; an oxidant channel is arranged between the inner nozzle and the outer nozzle; the metal inner nozzle is grounded and has a retraction distance L; the metal ring is sleeved on the outer wall sprayed by the outer nozzle, the length of the metal ring is larger than L, and the metal ring is connected with a high-voltage power supply; by adjusting L and α, the atomization effect and combustion efficiency can be adjusted. The invention combines the non-equilibrium plasma auxiliary combustion technology with the rocket engine injector design, thereby achieving the effects of shortening the ignition delay of the fuel such as methane and the like, widening the ignition limit, diffusing the flame to reach a stable state more quickly, and realizing quick ignition, high efficiency and stable combustion.)

1. The utility model provides a high-efficient stable combustion injector of medium and small thrust rocket engine which characterized in that: comprises an injection panel, a centrifugal plasma nozzle and a high-voltage power supply;

the centrifugal plasma nozzles are uniformly distributed on the injection panel in a concentric circle manner;

each centrifugal plasma nozzle comprises a metal inner nozzle, an insulating outer nozzle and a metal ring;

the insulating outer nozzle is coaxially sleeved on the periphery of the spraying end of the metal inner nozzle, and the inner wall surface of the spraying end of the insulating outer nozzle is provided with an expansion angle alpha; an oxidant channel is arranged between the insulating outer nozzle and the metal inner nozzle;

the center of the metal inner nozzle is provided with a fuel channel, and the injection end of the metal inner nozzle is retracted into L relative to the injection end of the insulating outer nozzle to form a propellant mixing chamber with the axial length of L;

the metal ring is coaxially sleeved on the outer side wall surface of the injection end of the insulating outer nozzle, and the axial length of the metal ring is greater than L;

the metal ring is electrically connected with a high-voltage power supply, and the metal inner nozzle is grounded through a lead;

and adjusting the L and the alpha to further adjust the atomization effect of the injector and the combustion efficiency of the engine.

2. The high efficiency stable combustion injector for medium and small thrust rocket engines according to claim 1, characterized in that: l =2mm, α =20 °.

3. The high efficiency stable combustion injector for medium and small thrust rocket engines according to claim 1, characterized in that: the combustion efficiency of the engine is adjusted by adjusting the distance and the number of the centrifugal plasma nozzles.

4. The high efficiency stable combustion injector for medium and small thrust rocket engines according to claim 3, characterized in that: the centrifugal plasma nozzle is in 2n +1 concentric circles on the injection panel, and is respectively a circle center plasma nozzle, a 1 st centrifugal plasma nozzle ring, a 2 nd centrifugal plasma nozzle ring, … … and a 2n centrifugal plasma nozzle ring from inside to outside; wherein n is more than or equal to 1 and is a positive integer.

5. The high efficiency stable combustion injector for medium and small thrust rocket engines according to claim 4, characterized in that: n =1, the spacing between two adjacent centrifugal plasma nozzle rings is 10mm, the total number of the centrifugal plasma nozzles is 19, the 1 st centrifugal plasma nozzle ring comprises 6 centrifugal plasma nozzles, and the 2 nd centrifugal plasma nozzle ring comprises 12 centrifugal plasma nozzles.

6. The high efficiency stable combustion injector for medium and small thrust rocket engines according to claim 4, characterized in that: the injection panel is an insulated single-layer injection panel, and an outer nozzle placing groove, a wire channel and an oxidant feeding channel are arranged in the single-layer injection panel; the number of the outer nozzle placing grooves is equal to that of the centrifugal plasma nozzles, and each outer nozzle placing groove can be used for placing an insulating outer nozzle sleeved with a metal ring;

the oxidant feeding channel is positioned on the top layer of the single-layer jetting panel and comprises an annular gas collecting cavity, a branch gas supply pipe and a gas inlet main pipe;

the number of the annular gas collecting cavities is n, one annular gas collecting cavity is arranged on a jetting panel between the 2n-1 th centrifugal plasma nozzle ring and the 2n th centrifugal plasma nozzle ring, and the annular gas collecting cavities are communicated with oxidant channels of each centrifugal plasma nozzle in the 2n-1 th centrifugal plasma nozzle ring and the 2n th centrifugal plasma nozzle ring through a branch gas supply pipe;

the air inlet main pipe is communicated with the oxidant channel of the circle center plasma nozzle and each annular gas collecting cavity;

the wire channel comprises an annular main wire, branch wires and a main inlet wire;

the number of the annular trunk lines is n, one annular trunk line is arranged on the injection panel between the 2n-1 th centrifugal plasma nozzle ring and the 2n th centrifugal plasma nozzle ring, and the annular trunk line cavities are electrically connected with the metal ring of each centrifugal plasma nozzle in the 2n-1 th centrifugal plasma nozzle ring and the 2n th centrifugal plasma nozzle ring through a branch line;

the main incoming line is electrically connected with the metal ring of the circle center plasma nozzle and each annular main line.

7. The high efficiency stable combustion injector for medium and small thrust rocket engines according to claim 6, characterized in that: the number of the air inlet main pipes is two, the air inlet main pipes are symmetrically distributed about the circle center plasma nozzle, and the two air inlet main pipes and the circle center plasma nozzle are positioned on the same diameter; the number of the main inlet wires is two, the main inlet wires are symmetrically distributed about the circle center plasma nozzle, and the two main inlet wires and the circle center plasma nozzle are also positioned on the same diameter.

8. The high efficiency stable combustion injector for medium and small thrust rocket engines according to claim 4, characterized in that: the jetting panel is a double-layer jetting panel and comprises an upper-layer insulating panel and a lower-layer metal panel which are coaxially arranged from top to bottom in sequence;

an inner nozzle placing groove and a fuel feeding channel are arranged in the upper insulating panel;

an outer nozzle placing groove and an oxidant feeding channel are arranged in the lower metal panel;

the number of the inner nozzle placing grooves is equal to that of the outer nozzle placing grooves and equal to that of the centrifugal plasma nozzles; the inner nozzle placing groove is used for placing the head of a metal inner nozzle in the centrifugal plasma nozzle, and the outer nozzle placing groove is used for placing an insulating outer nozzle and a metal ring and is in close contact with the metal ring; the lower metal panel is grounded through a lead;

the fuel feeding channel comprises an annular fuel collecting cavity, a branch liquid supply pipe and a liquid inlet main pipe;

the number of the annular fuel collecting cavities is n, an annular fuel collecting cavity is distributed on an injection panel between a 2n-1 th centrifugal plasma nozzle ring and a 2n th centrifugal plasma nozzle ring, and the annular fuel collecting cavities are communicated with fuel channels of each centrifugal plasma nozzle in the 2n-1 th centrifugal plasma nozzle ring and the 2n th centrifugal plasma nozzle ring through a branch liquid supply pipe;

the liquid inlet main pipe is communicated with the fuel channel of the circle center plasma nozzle and each annular liquid collecting cavity;

the oxidant supply channel comprises an annular gas collection cavity, a branch gas supply pipe and a gas inlet main pipe;

the number of the annular gas collecting cavities is n, one annular gas collecting cavity is arranged on a jetting panel between the 2n-1 th centrifugal plasma nozzle ring and the 2n th centrifugal plasma nozzle ring, and the annular gas collecting cavities are communicated with oxidant channels of each centrifugal plasma nozzle in the 2n-1 th centrifugal plasma nozzle ring and the 2n th centrifugal plasma nozzle ring through a branch gas supply pipe;

the air inlet main pipe is communicated with the oxidant channel of the circle center plasma nozzle and each annular gas collecting cavity.

9. The high efficiency stable combustion injector for medium and small thrust rocket engines according to claim 8, characterized in that: the number of the liquid inlet main pipes is two, the liquid inlet main pipes are symmetrically distributed about the circle center plasma nozzle, and the two liquid inlet main pipes and the circle center plasma nozzle are positioned on the same diameter; the number of the air inlet main pipes is two, the air inlet main pipes are symmetrically distributed about the circle center plasma nozzle, and the two air inlet main pipes and the circle center plasma nozzle are located on the same diameter.

10. The high efficiency stable combustion injector for medium and small thrust rocket engines according to claim 4, characterized in that: the centrifugal plasma nozzles in the 2 nth centrifugal plasma nozzle ring are all edge zone plasma nozzles, fuel is introduced into a fuel channel in each edge zone plasma nozzle, and an oxidant channel in each edge zone plasma nozzle is in a disconnected state and does not introduce oxidant.

Technical Field

The invention relates to the technical field of aerospace power devices, in particular to a high-efficiency stable combustion injector for a medium-small thrust rocket engine.

Background

The hydrocarbon fuel represented by methane and kerosene has the advantages of greenness, no toxicity, higher specific impulse, abundant reserves and the like, is the first choice of future space propulsion devices, and the posture and orbit control device of future carriers and spacecrafts using medium and small thrust liquid oxygen/methane rocket engines is increasingly paid attention by strong spacecrafts such as America and Russia. However, due to the severe space environment and the requirement for complex control tasks in the future, medium and small thrust liquid oxygen/methane rocket engines face a plurality of technical challenges such as reliable ignition at a low vacuum temperature, high-frequency pulse continuous ignition, stable combustion under variable working conditions and the like. Meanwhile, in order to ensure certain thrust and combustion efficiency, the pressure of a combustion chamber of the liquid oxygen-methane engine is generally higher, the combustion efficiency is improved by a high chamber pressure, a plurality of problems are caused, particularly, more severe requirements on ignition and combustion stability are provided, and the key for solving the problems lies in the design of an injector of the engine.

Injectors are one of the key components of liquid rocket engines and are usually composed of multiple nozzles. The main function of the device is to spray propellant into the combustion chamber according to the flow and mixing ratio of the designed working condition, realize the atomization and mixing of propellant components and organize the combustion in the combustion chamber. The liquid rocket engine has the typical structural characteristics that a plurality of spray holes or nozzles are arranged in a certain mode, the arrangement mode of the nozzles and the structural design of the injector have very important effects on the working performance of the liquid rocket engine, and the reasonable structural design and the nozzle arrangement not only can ensure that higher combustion efficiency is obtained, but also can effectively prevent any unstable combustion and reliably cool the combustion chamber.

Up to now, the variety of injectors has been quite varied, such as centrifugal, straight flow, shower head, two-strand counter-impact, two-strand self-impact, three-strand counter-impact, pin-lock, etc. In modern liquid rocket engines, the swirler finds a fairly wide range of applications, in particular the two-component swirler. The traditional design process generally adopts a method for changing structural parameters of the injector, but the method can only produce effects in limited working conditions, and meanwhile, because the spacecraft engine works in outer space with severe environment, the conditions of ignition failure or induced self-excitation instability and the like are easy to occur, and the requirements of variable working conditions, reusability and the like are difficult to meet.

Therefore, the injector is improved, the injectors for hydrocarbon fuels such as methane and the like are quickly ignited and efficiently and stably combusted, and important reference can be provided for the design of a future high-performance medium-low thrust rocket engine.

Disclosure of Invention

The invention aims to solve the technical problems in the prior art and provides a high-efficiency stable combustion injector of a medium-small thrust rocket engine, which combines a non-equilibrium plasma auxiliary combustion technology with a rocket engine injector design to exert the advantages of rapidness and flexibility of electric control combustion, shorten ignition delay time, widen ignition limit, promote flame to be rapid and stable and realize rapid ignition and high-efficiency stable combustion of the rocket engine.

In order to solve the technical problems, the invention adopts the technical scheme that:

a high-efficiency stable combustion injector for a medium-small thrust rocket engine comprises an injection panel, a centrifugal plasma nozzle and a high-voltage power supply.

The centrifugal plasma nozzles are uniformly distributed on the injection panel in a concentric circle manner.

Each centrifugal plasma nozzle includes a metal inner nozzle, an insulating outer nozzle, and a metal ring.

The insulating outer nozzle is coaxially sleeved on the periphery of the spraying end of the metal inner nozzle, and the inner wall surface of the spraying end of the insulating outer nozzle is provided with an expansion angle alpha; an oxidant channel is arranged between the insulating outer nozzle and the metal inner nozzle.

The center of the metal inner nozzle is provided with a fuel channel, and the injection end of the metal inner nozzle is retracted L relative to the injection end of the insulating outer nozzle to form a propellant mixing chamber with the axial length of L.

The metal ring is coaxially sleeved on the outer side wall surface of the injection end of the insulating outer nozzle, and the axial length of the metal ring is larger than L.

The metal ring is electrically connected with a high-voltage power supply, and the metal inner nozzle is grounded through a lead.

And adjusting the L and the alpha to further adjust the atomization effect of the injector and the combustion efficiency of the engine.

L＝2mm，α＝20°。

The combustion efficiency of the engine is adjusted by adjusting the distance and the number of the centrifugal plasma nozzles.

The centrifugal plasma nozzle is in 2n +1 concentric circles on the injection panel, and is respectively a circle center plasma nozzle, a 1 st centrifugal plasma nozzle ring, a 2 nd centrifugal plasma nozzle ring, … … and a 2n centrifugal plasma nozzle ring from inside to outside; wherein n is more than or equal to 1 and is a positive integer.

n is 1, the spacing between two adjacent centrifugal plasma nozzle rings is 10mm, the total number of the centrifugal plasma nozzles is 19, the 1 st centrifugal plasma nozzle ring comprises 6 centrifugal plasma nozzles, and the 2 nd centrifugal plasma nozzle ring comprises 12 centrifugal plasma nozzles.

The injection panel is an insulated single-layer injection panel, and an outer nozzle placing groove, a wire channel and an oxidant feeding channel are arranged in the single-layer injection panel; the quantity of outer nozzle standing groove equals with centrifugal plasma nozzle's quantity, and every outer nozzle standing groove all can place the insulating outer nozzle that the cover was equipped with the becket.

The oxidant supply channel is positioned on the top layer of the single-layer injection panel and comprises an annular gas collecting cavity, a branch gas supply pipe and a gas inlet main pipe.

The number of the annular gas collecting cavities is n, one annular gas collecting cavity is arranged on a gas injection panel between the 2n-1 st centrifugal plasma nozzle ring and the 2n nd centrifugal plasma nozzle ring, and the annular gas collecting cavities are communicated with oxidant channels of each centrifugal plasma nozzle in the 2n-1 st centrifugal plasma nozzle ring and the 2n nd centrifugal plasma nozzle ring through a branch gas supply pipe.

The air inlet main pipe is communicated with the oxidant channel of the circle center plasma nozzle and each annular gas collecting cavity.

The wire passage includes a ring trunk, branch lines, and a main incoming line.

The number of the annular mainlines is n, one annular mainline is arranged on the injection panel between the 2n-1 st centrifugal plasma nozzle ring and the 2n nd centrifugal plasma nozzle ring, and the annular mainline cavities are electrically connected with the metal ring of each centrifugal plasma nozzle in the 2n-1 st centrifugal plasma nozzle ring and the 2n nd centrifugal plasma nozzle ring through a branch line.

The main incoming line is electrically connected with the metal ring of the circle center plasma nozzle and each annular main line.

The number of the air inlet main pipes is two, the air inlet main pipes are symmetrically distributed about the circle center plasma nozzle, and the two air inlet main pipes and the circle center plasma nozzle are positioned on the same diameter; the number of the main inlet wires is two, the main inlet wires are symmetrically distributed about the circle center plasma nozzle, and the two main inlet wires and the circle center plasma nozzle are also positioned on the same diameter.

The injection panel is a double-layer injection panel and comprises an upper-layer insulating panel and a lower-layer metal panel which are coaxially arranged from top to bottom in sequence.

The upper insulating panel is provided with an inner nozzle placing groove and a fuel supply channel.

An outer nozzle placing groove and an oxidant supply channel are arranged in the lower metal panel.

The number of the inner nozzle placing grooves is equal to that of the outer nozzle placing grooves and equal to that of the centrifugal plasma nozzles; the inner nozzle placing groove is used for placing the head of a metal inner nozzle in the centrifugal plasma nozzle, and the outer nozzle placing groove is used for placing an insulating outer nozzle and a metal ring and is in close contact with the metal ring; the lower metal panel is grounded through a lead.

The fuel feed passage includes an annular fuel collection chamber, a branch feed pipe and a liquid inlet manifold.

The number of the annular fuel collecting cavities is n, an annular fuel collecting cavity is arranged on an injection panel between the 2n-1 st centrifugal plasma nozzle ring and the 2n nd centrifugal plasma nozzle ring, and the annular fuel collecting cavities are communicated with the fuel channels of each centrifugal plasma nozzle in the 2n-1 st centrifugal plasma nozzle ring and the 2n nd centrifugal plasma nozzle ring through a branch liquid supply pipe.

The liquid inlet main pipe is communicated with the fuel channel of the circle center plasma nozzle and each annular liquid collecting cavity.

The oxidant supply passage includes an annular gas collection chamber, a branch gas supply pipe and a gas inlet manifold.

The number of the annular gas collecting cavities is n, one annular gas collecting cavity is arranged on a gas injection panel between the 2n-1 st centrifugal plasma nozzle ring and the 2n nd centrifugal plasma nozzle ring, and the annular gas collecting cavities are communicated with oxidant channels of each centrifugal plasma nozzle in the 2n-1 st centrifugal plasma nozzle ring and the 2n nd centrifugal plasma nozzle ring through a branch gas supply pipe.

The air inlet main pipe is communicated with the oxidant channel of the circle center plasma nozzle and each annular gas collecting cavity.

The number of the liquid inlet main pipes is two, the liquid inlet main pipes are symmetrically distributed about the circle center plasma nozzle, and the two liquid inlet main pipes and the circle center plasma nozzle are positioned on the same diameter; the number of the air inlet main pipes is two, the air inlet main pipes are symmetrically distributed about the circle center plasma nozzle, and the two air inlet main pipes and the circle center plasma nozzle are located on the same diameter.

The centrifugal plasma nozzles in the 2 nth centrifugal plasma nozzle ring are all edge zone plasma nozzles, fuel is introduced into a fuel channel in each edge zone plasma nozzle, and an oxidant channel in each edge zone plasma nozzle is in a disconnected state and does not introduce oxidant.

The invention has the following beneficial effects:

(1) the traditional mechanical control atomization mode is changed, the efficient and stable combustion injector of the whole medium and small thrust rocket engine fully utilizes the structural characteristics of a double-component centrifugal nozzle and the structural characteristics of an injection panel of the medium and small thrust liquid rocket engine, a dielectric barrier discharge electrode is integrated into the injector, the injection panel propellant channel and a wire channel are reasonably designed, the device is high in modularization degree, compact in structure and good in stability, the electrodes can continuously run for a long time, and the power consumption is very low.

(2) The invention adopts the annular array type nonequilibrium state plasma exciter group, can generate abundant active groups in large volume and release certain heat, can also promote the mixing of fuel and oxidant by utilizing the pneumatic benefit of the plasma, and is beneficial to realizing the high-efficiency stable combustion of medium and small thrust rocket engines.

(3) The high-efficiency stable combustion injector for the medium-small thrust rocket engine can realize excitation in different modes and strengths by adjusting power supply parameters or replacing high-voltage power supply types, has quick response, no moving mechanical parts, adjustable excitation parameters, various types and wide range, and can effectively control propellant jet flow.

Drawings

Fig. 1 shows a schematic diagram of an efficient stable combustion injector (without an injection panel) of a medium-small thrust rocket engine.

Fig. 2 shows a schematic view of the structure of the metallic inner nozzle of the present invention.

Fig. 3 shows a schematic view of the structure of the insulated outer nozzle according to the present invention.

FIG. 4 shows a schematic view of the arrangement of the centrifugal plasma nozzle on the injection faceplate in the present invention.

FIG. 5 is a schematic view showing the installation of a center plasma nozzle and a single-layered injection panel according to the present invention.

Fig. 6 shows a schematic view of the structure of the oxidizer supply channel of fig. 5.

Fig. 7 shows a schematic view of the structure of the wire passage in fig. 5.

FIG. 8 is a view illustrating the installation of the center plasma nozzle and the double-layered injection panel according to the present invention.

Fig. 9 shows a schematic view of the structure of the fuel feed channel in fig. 8.

FIG. 10 shows a simulated distribution of the temperature of O atoms participating in multi-step reactive combustion in a combustion chamber.

Among them are:

1. an injection panel;

10. a single layer injection panel;

11. an oxidant feed passage; 111. an annular gas collection chamber; 112. a branched gas supply pipe; 113. a main air inlet pipe;

12. a wire passage; 121. an annular trunk line; 122. a branch line; 123. a main incoming line;

13. an outer nozzle placement groove;

20. a double-layer injection panel;

21. an upper insulating panel; 22. a lower metal panel;

23. a fuel feed passage;

231. an annular fuel plenum; 232. a branched liquid supply tube; 233. a total liquid inlet pipe; 234. an inner nozzle placing groove;

30. a centrifugal plasma nozzle;

31. a metallic inner nozzle;

311. a metal rod; 312. an inner nozzle swirl chamber; 313. a fuel tangential bore; 314. an inner nozzle flange; 315. an inner nozzle;

32. an insulating outer nozzle;

321. an outer nozzle swirl chamber; 322. oxidant tangential holes; 323. an outer nozzle; 324. an outer nozzle flange; 325. a threaded hole;

33. a metal ring;

34. a propellant blending chamber; 35. a circle center plasma nozzle; 36. a border region plasma nozzle;

40. a high voltage power supply.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific preferred embodiments.

In the description of the present invention, it is to be understood that the terms "left side", "right side", "upper part", "lower part", etc., indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and that "first", "second", etc., do not represent an important degree of the component parts, and thus are not to be construed as limiting the present invention. The specific dimensions used in the present example are only for illustrating the technical solution and do not limit the scope of protection of the present invention.

As shown in figures 1 and 4, the efficient stable combustion injector for the medium and small thrust rocket engine comprises an injection panel 1, a centrifugal plasma nozzle 30 and a high-voltage power supply 40.

As shown in fig. 4, 6 and 7, the centrifugal plasma nozzles are preferably uniformly arranged on the injection panel in the form of 2n +1 concentric circles. 2n +1 concentric circles which are respectively a circle center plasma nozzle 35, a 1 st centrifugal plasma nozzle ring, a 2 nd centrifugal plasma nozzle ring, … … and a 2n centrifugal plasma nozzle ring from inside to outside; wherein n is more than or equal to 1 and is a positive integer. The combustion efficiency of the engine is adjusted by adjusting the distance and the number of the centrifugal plasma nozzles.

In the present invention, the radial plasma nozzles in the 2 n-th centrifugal plasma nozzle ring are all the edge zone plasma nozzles 36, and the area of the radial plasma nozzle located inside the edge zone plasma nozzle is referred to as a center zone plasma nozzle.

The arrangement of the plasma nozzles in the central area can fully mix the fuel and the oxidant, generate thrust and prevent unstable combustion. The edge zone plasma nozzle is intended to provide reliable cooling of the combustion chamber wall. In the embodiment, the fuel channel in each edge zone plasma nozzle is filled with fuel, the oxidant channel in each edge zone plasma nozzle is in a disconnected state, no oxidant is filled, namely, no oxygen is filled, so that the residual oxygen coefficient of the edge zone plasma nozzle is reduced, and a better inner cooling liquid film is ensured. Alternatively, each of the edge zone plasma nozzles may be only a single component swirler.

In this embodiment, preferably, n is 1, the spacing between two adjacent centrifugal plasma nozzle rings is 10mm, the total number of centrifugal plasma nozzles is 19, the 1 st centrifugal plasma nozzle ring includes 6 centrifugal plasma nozzles, and the 2 nd centrifugal plasma nozzle ring includes 12 centrifugal plasma nozzles.

As shown in fig. 1, each of the centrifugal plasma nozzles includes a metal inner nozzle 31, an insulating outer nozzle 32, and a metal ring 33.

The insulating outer nozzle is coaxially sleeved on the periphery of the spraying end of the metal inner nozzle, and the inner wall surface of the spraying end of the insulating outer nozzle is provided with an expansion angle alpha; an oxidant channel is arranged between the insulating outer nozzle and the metal inner nozzle. The material of the insulating outer nozzle is preferably polytetrafluoroethylene (teflon), ceramic, quartz, or polyimide (Kapton), and in this embodiment, ceramic is preferable in view of the temperature range near the nozzle outlet after forming the flame and the difficulty of machining.

As shown in FIG. 3, the insulated outer nozzle includes, in order from the head to the tip, an outer nozzle flange 324, an outer nozzle swirl chamber 321, and an outer nozzle 323. Wherein, oxidant tangential holes 322 communicated with the oxidant channel are uniformly arranged along the circumferential direction of the outer nozzle swirl chamber. The outer nozzle flange 324 is circumferentially provided with a threaded bore 325.

The center of the metal inner nozzle is provided with a fuel channel, and as shown in fig. 2, the metal inner nozzle comprises a metal rod 311, an inner nozzle swirl chamber 312, an inner nozzle flange 314 and an inner nozzle 315 in sequence from the head to the spray end. Wherein, the inner nozzle swirl chamber is evenly provided with fuel tangential holes 313 communicated with the fuel channel along the circumferential direction. The inner nozzle flange 314 and the outer nozzle flange 324 are in threaded sealing connection through bolts and threaded holes.

The spray end of the metallic inner nozzle is set back L relative to the spray end of the insulated outer nozzle to form a propellant blending chamber 34 of axial length L.

The metal ring is coaxially sleeved on the outer side wall surface of the injection end of the insulating outer nozzle, and the axial length of the metal ring is larger than L.

The metal ring is electrically connected with a high-voltage power supply, and the metal inner nozzle is grounded through a lead. The metal ring and the metal inner nozzle are both preferably made of stainless steel materials.

According to the invention, the atomization effect of the injector and the combustion efficiency of the engine are further adjusted by adjusting L and alpha. In the present embodiment, L is preferably 2mm, and α is preferably 20 °.

In the present invention, the injection panel preferably adopts two structures:

single-layer injection panel with insulating injection panel

As shown in fig. 5, the single-layered injection panel is provided therein with an outer nozzle placement groove 13, a wire passage 12, and an oxidizer supply passage 11; the quantity of outer nozzle standing groove equals with centrifugal plasma nozzle's quantity, and every outer nozzle standing groove all can place the insulating outer nozzle that the cover was equipped with the becket. At the moment, the metal inner nozzle is coaxially inserted into the outer nozzle except the inner nozzle, other parts of the metal inner nozzle are exposed outside the single-layer injection panel, and the metal rod is connected with a high-voltage power supply through a wire.

As shown in fig. 6, the oxidant feed channels are located in the top layer of the single-layer injector panel and include an annular gas collection chamber 111, branch gas supply tubes 112 and a gas inlet manifold 113.

The number of the annular gas collecting cavities is n, one annular gas collecting cavity is arranged on a gas injection panel between the 2n-1 st centrifugal plasma nozzle ring and the 2n nd centrifugal plasma nozzle ring, and the annular gas collecting cavities are communicated with oxidant channels of each centrifugal plasma nozzle in the 2n-1 st centrifugal plasma nozzle ring and the 2n nd centrifugal plasma nozzle ring through a branch gas supply pipe.

In this embodiment, since n ═ 1, the oxidant feed channel includes only one annular gas collection chamber.

The air inlet main pipe is communicated with the oxidant channel of the circle center plasma nozzle and each annular gas collecting cavity. Preferably, the number of the air inlet main pipes is two, the air inlet main pipes are symmetrically distributed about the circle center plasma nozzle, and the two air inlet main pipes and the circle center plasma nozzle are located on the same diameter. Thus, the number of external pipelines can be reduced, and air inlet can be facilitated. The propellant is filled in the gas collecting cavity and then enters the nozzle, and the air inflow is consistent and uniform.

As shown in fig. 7, the wire passage includes a ring trunk wire 121, branch wires 122, and a trunk wire 123.

The number of the annular mainlines is n, one annular mainline is arranged on the injection panel between the 2n-1 st centrifugal plasma nozzle ring and the 2n nd centrifugal plasma nozzle ring, and the annular mainline cavities are electrically connected with the metal ring of each centrifugal plasma nozzle in the 2n-1 st centrifugal plasma nozzle ring and the 2n nd centrifugal plasma nozzle ring through a branch line.

The main incoming line is electrically connected with the metal ring of the circle center plasma nozzle and each annular main line. The number of the main inlet wires is two, the main inlet wires are symmetrically distributed about the circle center plasma nozzle, and the two main inlet wires and the circle center plasma nozzle are also positioned on the same diameter. The other ends of the two main incoming lines are grounded through wires respectively.

The second and injection panel is a double-layer injection panel

As shown in fig. 8, the double-layer injection panel comprises an upper insulating panel 21 and a lower metal panel 22 which are coaxially arranged from top to bottom.

The upper insulating panel is provided therein with an inner nozzle placement groove 234 and a fuel supply passage 23.

As shown in fig. 9, the fuel supply passage includes an annular fuel header 231, a branch supply pipe 232, and an inlet manifold 233.

The number of the annular fuel collecting cavities is n, an annular fuel collecting cavity is arranged on an injection panel between the 2n-1 st centrifugal plasma nozzle ring and the 2n nd centrifugal plasma nozzle ring, and the annular fuel collecting cavities are communicated with the fuel channels of each centrifugal plasma nozzle in the 2n-1 st centrifugal plasma nozzle ring and the 2n nd centrifugal plasma nozzle ring through a branch liquid supply pipe.

The liquid inlet main pipe is communicated with the fuel channel of the circle center plasma nozzle and each annular liquid collecting cavity. The number of the liquid inlet main pipes is two, the liquid inlet main pipes are symmetrically distributed about the circle center plasma nozzle, and the two liquid inlet main pipes and the circle center plasma nozzle are located on the same diameter. The double-layer structure can place the whole nozzle into the jetting panel, and compared with a single-layer panel, the double-layer structure is provided with more fuel liquid collecting cavities, and meanwhile, the nozzle is convenient to replace. The number of external pipelines can be reduced, and air inlet can be facilitated. The propellant is filled in the gas collecting cavity and then enters the nozzle, and the air inflow is consistent. The lower panel is made of metal materials, so that the whole body can be grounded, a wire channel is not required to be arranged, the cost is saved, and the processing difficulty is reduced.

The lower metal panel is provided therein with an outer nozzle placement groove 13 and an oxidizer supply passage 11.

The number of the inner nozzle placing grooves is equal to that of the outer nozzle placing grooves and equal to that of the centrifugal plasma nozzles; in the embodiment, only the metal rod in the metal inner nozzle is exposed out of the inner nozzle placing groove and is connected with a high-voltage power supply through a lead.

The outer nozzle placing groove is used for placing the insulating outer nozzle and the metal ring and is tightly contacted with the metal ring; the lower metal panel is grounded through a lead.

The oxidant supply passage includes an annular gas collection chamber, a branch gas supply pipe and a gas inlet manifold. The specific layout method is the same as that in embodiment 1, and is not described herein again.

The setting of double-deck spouting panel can solve when adopting the individual layer to spout the panel, and the naked hourglass of nozzle is outside at the individual layer spouting panel in the metal, and inconvenient supply with methane, and the pre-buried wire degree of difficulty is big, the technical problem of inconvenient processing and connection.

In this embodiment, the metal inner nozzle and the high voltage power supply form a high voltage electrode, the metal ring is grounded to form a ground electrode, the insulating outer nozzle is an insulating dielectric barrier layer, and the metal inner nozzle, the insulating outer nozzle, the metal ring and the high voltage power supply together form a dielectric barrier discharge exciter. Assuming that the ambient pressure is P1 atm, the applied voltage U10 kV, and the relative dielectric constant ε of the gas_gAbout.1.0 (1.0000585 for air and 1.00051 for oxygen at 0 ℃), relative dielectric constant ε of insulated outer nozzle_d10.0 (at 20 ℃), the minimum value min (eg) of the air gap field intensity at the inner wall surface (r ═ 5mm) of the nozzle immediately outside the plasma air gap space is about: 7.0X 106V/m, at this timeWherein Eg is the electric field intensity of the air gap space before discharge; the non-equilibrium plasma generating condition is met, the upper limit of the pressure capable of generating the plasma is 23.02atm, and the working pressure range of a combustion chamber of a general medium-small thrust rocket engine is covered.

In this embodiment, the fuel is preferably methane and the oxidant is preferably oxygen.

The centrifugal plasma nozzle has the advantages that under typical working conditions (the parameters of a high-voltage power supply are fixed, namely the high-voltage frequency f is 200Hz, and the duty ratio C is 50%), the discharge power is lower than 30W, and the cost-efficiency ratio is very low (lower than 1% under the optimized parameters).

In addition, with the increase of the excitation voltage, the discharge phenomenon is more obvious, the concentration of plasma discharge particles is increased, the discharge intensity is enhanced, the temperature is increased, and the discharge power is increased.

The invention carries out combustion simulation aiming at methane and oxygen, and the parameters of the methane and the oxygen are set as follows:

1. a methane inlet: the Velocity value (Velocity magnetic) was set to 1m/s, the turbulence definition Method (Specification Method) selected the turbulence Intensity and Hydraulic Diameter (Intensity and Hydraulic Diameter), and the calculated turbulence Intensity was set to 0.8% for the methane inlet and the Hydraulic Diameter was 1 mm. The temperature was maintained at a default setting of 300K, setting the mass fraction of methane to 1 and the mass fraction of the other components to 0.

2. An oxygen inlet: the Velocity value (Velocity magnetic) was set to 3m/s, the turbulence definition Method (Specification Method) selected the turbulence Intensity and the Hydraulic Diameter (Intensity and Hydraulic Diameter), and the calculated turbulence Intensity for setting the oxygen inlet to 0.8% and the Hydraulic Diameter to 1 mm. The temperature is maintained at a default setting of 300K, the mass fraction of oxygen is set to 1, and the mass fraction of the other components is set to 0.

3. A pressure outlet: the Pressure value (Gauge Pressure) was set to 101325Pa, the turbulence definition Method (Specification Method) selected turbulence Intensity and Hydraulic Diameter (Intensity and Hydraulic Diameter), and the calculated turbulence Intensity was set to 1% at the outlet and Hydraulic Diameter was 60 mm.

In the combustion simulation, the flame with the time of 0.5s is selected for comparison and analysis in the results, and under the multi-step elementary reaction combustion with the participation of O atoms, the jet flow generates an obvious gradient after being sprayed out, which indicates that the mixing of liquid oxygen and methane is slowed down.

Although the preferred embodiments of the present invention have been described in detail, the present invention is not limited to the details of the embodiments, and various equivalent modifications can be made within the technical spirit of the present invention, and the scope of the present invention is also within the scope of the present invention.