JP2008111340A - Injector and combustor for rocket - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an injector for a rocket and a combustor for the rocket, capable of restraining amplification of combustion vibration in a combustion chamber caused by a standing wave from the injector for the rocket. <P>SOLUTION: Since this combustor has the combustion chamber 3 combustible by mixing an oxidizing agent with fuel and an inner cylinder 21 capable of injecting the oxidizing agent toward the combustion chamber 3 from an oxidizing agent flow passage 23 formed in a cylindrical shape and arranged inside and having a tip part 21a projected to the combustion chamber 3 side from an injection surface 31 of the combustion chamber 3 into which the fuel is injected, the amplification of the combustion vibration in the combustion chamber 3 caused by the standing wave from the injector for the rocket can be restrained. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rocket injector and a rocket combustor, and more particularly to a rocket injector and a rocket combustor applied to a rocket engine that obtains thrust by mixing and burning an oxidant and fuel. is there.

A conventional rocket combustor mounted on a rocket engine is composed of a number of injectors, combustion chambers, nozzles, and the like, and uses energy from the chemical reaction of fuel as a propellant. Thrust is obtained by converting into exhaust motion. That is, fuel (for example, hydrogen gas: GH ₂ ) and oxidant (for example, liquid oxygen: LOx) are injected and injected from the injector into the combustion chamber, and after ignition, the combustion gas generated in the combustion chamber is throttled by the nozzle. , Exhausted in the direction of combustion gas discharge, producing thrust.

  In such a rocket combustor, due to the recent demand for higher rocket engine efficiency, it is necessary to perform high load combustion with a very high energy density locally in the combustion chamber. Generation of combustion vibration that resonates with sound becomes a problem. In particular, in a combustor in which the inner diameter of the combustion chamber is constant, combustion vibration having a natural frequency occurs, which becomes a problem during combustion.

  In order to suppress such a resonance phenomenon in the combustion chamber, a conventional rocket combustor is equipped with a baffle blade (Baffle Blade) and a baffle hub (Baffle Hub) in the vicinity of the fuel and oxidant injection surfaces in the combustion chamber. Therefore, there are some which suppress the generation of the surface mode in the combustion chamber and suppress the combustion vibration.

  However, in this case, since the baffle blade and the baffle hub are inserted into the high-temperature combustion gas, it is necessary to cool them, and the combustor structure becomes complicated, and the cooling effect may cause a decrease in combustion efficiency. is there. Also, the mounting of the baffle blade and the baffle hub itself increases the weight of the rocket combustor, which is a factor against the demand for higher efficiency of the rocket engine.

  In response to this problem, for example, in the rocket injector described in Patent Document 1, the LOx post connected to the back surface of the wall on which the injection surface of the combustion chamber is formed, and the LOx flow provided in the LOx post In order to prevent resonance between the standing wave formed in the LOx post and the acoustic frequency of the surface mode of the combustion chamber, the frequency of the standing wave formed in the LOx post during combustion is combusted. The position of the orifice in the LOx post, the shape and member of the orifice, or the shock-absorbing member provided in the LOx post so as to detune from the acoustic frequency of the chamber surface mode or suppress the standing wave It is determined. As a result, the frequency of the standing wave from the rocket injector is deviated from the acoustic frequency of the surface mode in the combustion chamber, and the combustion vibration due to the standing wave from the rocket injector in the combustor is amplified. It is suppressed.

JP 2006-97639 A

By the way, in such a rocket combustor, an injector composed of a large number of injection tubes injects LOx and GH ₂ into the combustion chamber as described above, and finely mixes and combusts the rocket. It is one of the main factors that determine engine performance. And as such a conventional injector, for example, an annular outer gap is formed between the inner cylinder and the inner cylinder in which a flow path through which LOx passes at a speed of 10 to 20 m / S is formed, An outer cylinder that allows GH ₂ to pass through the gap at a speed about 10 times that of LOx is provided, and a recess is provided at the combustion chamber side end of the inner cylinder by making the inner cylinder shorter than the outer cylinder. In some cases, LOx and GH ₂ collide to promote atomization and mixing.

However, in such a conventional injector, the mixing of LOx and GH ₂ is disturbed at the injector outlet, thereby increasing the pressure fluctuation in the recess, and this pressure fluctuation is propagated into the inner cylinder and GH. _When a part of ₂ enters and exits the upstream side in the inner cylinder, the LOx flow rate in the inner cylinder fluctuates periodically. As a result, the standing wave of the natural frequency is excited in the LOx liquid column in the inner cylinder, and the standing wave and the acoustic frequency of the surface mode of the combustion chamber may resonate, thereby amplifying the combustion vibration. .

  Therefore, an object of the present invention is to provide a rocket injector and a rocket combustor that can suppress amplification of combustion vibration in a combustion chamber caused by a standing wave from the rocket injector.

  In order to achieve the above object, a rocket injector according to a first aspect of the present invention includes a combustion chamber in which an oxidant and a fuel can be mixed and burned, and an oxidant flow path formed in a cylindrical shape and provided therein. And an inner cylinder having a tip protruding from the injection surface of the combustion chamber to which the fuel is injected and projecting toward the combustion chamber.

  In the rocket injector according to a second aspect of the present invention, the inner cylinder is set such that the protruding amount of the tip from the injection surface is at least larger than 0 and not more than 1.0 times the outer diameter of the inner cylinder. It is characterized by being.

  In the rocket injector according to a third aspect of the present invention, the tip of the inner cylinder has an inner diameter that decreases toward the combustion chamber.

  In a rocket injector according to a fourth aspect of the present invention, the outer periphery of the inner cylinder is covered and formed in a cylindrical shape, connected to the injection surface, and directed from the fuel flow path between the inner cylinder and the combustion chamber. An outer cylinder capable of injecting the fuel is provided.

  In a rocket injector according to a fifth aspect of the present invention, the tip of the fuel flow path has an outer diameter that decreases toward the combustion chamber.

  In a rocket injector according to a sixth aspect of the present invention, the tip of the fuel flow path has an inner diameter that decreases toward the combustion chamber.

  In order to achieve the above object, a combustor for a rocket according to a seventh aspect of the invention is provided with a combustion chamber in which an oxidizing agent and a fuel are mixed and burned to generate combustion gas, and is formed in a cylindrical shape and provided therein. An inner cylinder capable of injecting the oxidant from the oxidant flow path toward the combustion chamber and having a tip protruding from the injection surface of the combustion chamber to which the fuel is injected toward the combustion chamber; and the inner cylinder A plurality of injectors having a cylindrical shape that covers the outer periphery of the cylinder and is connected to the injection surface and capable of injecting the fuel from the fuel flow path between the inner cylinder and the combustion chamber toward the combustion chamber And a nozzle that is connected to the combustion chamber and raises thrust by narrowing an outlet of the combustion gas injected from the combustion chamber.

  According to the rocket injector of the first aspect of the present invention, the fuel is injected into the tip portion of the inner cylinder from which the oxidant can be injected toward the combustion chamber from the oxidant flow path formed in the cylinder and provided inside. Protruding from the injection surface of the combustion chamber to the combustion chamber side, the oxidant and the fuel are mixed in the combustion chamber having a relatively large volume, resulting in disturbance of the mixing of the oxidant and the fuel. As a result, pressure fluctuation is suppressed, and pressure fluctuation propagating into the inner cylinder is reduced and fuel is prevented from flowing into the upstream side of the inner cylinder. As a result, the standing wave of the natural frequency in the inner cylinder is suppressed. Therefore, amplification of combustion vibrations in the combustion chamber due to standing waves from the rocket injector can be suppressed.

  According to the rocket injector of the second aspect of the present invention, the amount of protrusion of the inner cylinder tip from the injection surface is set to be at least larger than 0 and not more than 1.0 times the outer diameter of the inner cylinder. The tip of the inner cylinder protrudes from the injection surface on which the fuel is injected toward the combustion chamber to reliably suppress pressure fluctuations caused by the turbulent mixing of the oxidant and the fuel, and the oxidant and the fuel in the combustion chamber. When these are mixed and burned, it is possible to prevent the tip portion of the inner cylinder from being burnt by this combustion.

  According to the rocket injector of the third aspect of the invention, the flow rate of the oxidant flowing in the vicinity of the inner wall surface of the inner cylinder tip is reduced by forming the inner diameter of the inner cylinder tip toward the combustion chamber. Therefore, it is possible to prevent the formation of a region where the flow rate of the oxidant is low in the inner cylinder and to make the flow rate of the oxidant in the inner cylinder uniform, thereby preventing the fuel from flowing back into the inner cylinder. It can be surely prevented.

  According to the rocket injector of the fourth aspect of the present invention, the outer cylinder is covered with the outer cylinder, is formed in a cylindrical shape, is connected to the injection surface, and fuel is supplied from the fuel flow path between the inner cylinder and the combustion chamber. Since the injectable outer cylinder is provided, a fuel flow path can be formed between the inner cylinder and the outer cylinder so as to cover the inner cylinder, and combustion is thereby performed from the oxidant flow path inside the inner cylinder. The oxidant injected toward the chamber and the fuel injected from the fuel flow path outside the inner cylinder toward the combustion chamber can be reliably contacted and mixed.

  According to the rocket injector of the fifth aspect of the invention, the fuel flow path between the inner cylinder and the outer cylinder is formed by forming the outer diameter of the tip of the fuel flow path so as to become smaller toward the combustion chamber. Since the fuel injected from the fuel is injected toward the oxidant injected from the oxidant flow path inside the inner cylinder, atomization is promoted by the collision effect of the fuel and oxidant, and the fuel and oxidant are more separated. Can be mixed efficiently.

  According to the rocket injector of the sixth aspect of the invention, by forming the inner diameter of the tip of the fuel flow path so as to become smaller toward the combustion chamber, the fuel flow path between the inner cylinder and the outer cylinder is removed. Since the injected fuel can be more reliably injected toward the oxidant, the efficiency of mixing the fuel and the oxidant can be further improved.

  According to the rocket combustor of the seventh aspect of the present invention, combustion is performed from a combustion chamber in which an oxidant and fuel are mixed and burned to generate combustion gas, and a cylindrically formed oxidant flow path provided inside. An inner cylinder in which the oxidizer can be injected toward the chamber and the tip protrudes from the injection surface of the combustion chamber to which the fuel is injected, and the outer surface of the inner cylinder covers the outer periphery of the inner cylinder, and is formed in a cylindrical shape. And a plurality of injectors having an outer cylinder capable of injecting fuel from a fuel flow path between the inner cylinder and the inner cylinder toward the combustion chamber, and combustion connected to the combustion chamber and injected from the combustion chamber Since it has a nozzle that increases thrust by narrowing the gas outlet, oxidant and fuel injected from the injector toward the combustion chamber are mixed and burned in this combustion chamber, and combustion gas is generated. , Narrow the outlet of the combustion gas injected from the combustion chamber by the nozzle It is possible to increase the thrust, get a thrust in the. During this time, the tip of the inner cylinder that is capable of injecting oxidant from the oxidant flow path that is formed in the cylinder and is provided toward the combustion chamber is closer to the combustion chamber than the injection surface of the combustion chamber from which fuel is injected. By projecting, the oxidizer and the fuel are mixed in the combustion chamber having a relatively large volume, so that the pressure fluctuation caused by the turbulent mixing of the oxidizer and the fuel is suppressed. The pressure fluctuation propagating to the inner cylinder is reduced and the fuel is prevented from flowing into the upstream side of the inner cylinder. As a result, the standing wave of the natural frequency in the inner cylinder is prevented from being excited. Amplification of combustion vibrations in the combustion chamber due to standing waves from can be suppressed.

  Exemplary embodiments of a rocket injector and a rocket combustor according to the present invention will be described below in detail with reference to the accompanying drawings. In addition, this invention is not limited by this Example.

  FIG. 1 is a schematic cross-sectional view showing a schematic configuration of a rocket injector according to a first embodiment of the present invention, and FIG. 2 shows a rocket combustor to which the rocket injector according to the first embodiment of the present invention is applied. FIG. 3 is a schematic perspective view showing a schematic configuration of the rocket injector according to the first embodiment of the present invention, and FIG. 4 is a rocket injection according to the first embodiment of the present invention. It is a schematic diagram which shows an example of the CFD analysis result of the combustor for rockets which applied the combustor.

In this embodiment, as shown in FIGS. 2 and 3, the rocket combustor 1 includes a number of rocket injectors 2, a combustion chamber 3, and a nozzle 4. The thrust is obtained by converting the energy resulting from the chemical reaction of the fuel that is the propellant into the exhaust motion. That is, an oxidizing agent (for example, liquid oxygen, hereinafter referred to as “LOx”) and fuel (for example, hydrogen gas, hereinafter referred to as “GH ₂ ”) injected from the injector 2 toward the combustion chamber 3 are contained in the combustion chamber 3. The fuel is mixed and burned in order to generate combustion gas, and the thrust can be increased by narrowing the outlet of the combustion gas injected from the combustion chamber 3 by the nozzle 4 to obtain the thrust.

Specifically, as described above, each rocket injector 2 is for injecting LOx and GH ₂ into the combustion chamber 3, and includes an LOx post 21 as an inner cylinder and a sleeve 22 as an outer cylinder. Is provided. The LOx post 21 is formed in a cylindrical shape, and an LOx channel 23 as an oxidant channel is formed therein. The LOx post 21 can take in LOx supplied from the supply device into the LOx flow path 23 from one end side and inject the taken LOx toward the combustion chamber 3 from the other end side. Further, an orifice 24 is provided inside the LOx post 21, that is, on one end side of the LOx flow path 23, and the LOx taken into the LOx flow path 23 can be rectified by the orifice 24.

  Further, a sleeve mounting portion 25 and a recess 26 are provided on the outer peripheral surface of the LOx post 21. The sleeve mounting portion 25 is formed in a disk shape protruding outward from the LOx post 21. The sleeve mounting portion 25 is formed perpendicular to the axial direction of the LOx post 21. The recess 26 is formed on the downstream side of the sleeve mounting portion 25 with respect to the flow direction of LOx flowing through the LOx flow path 23, that is, on the combustion chamber 3 side. The recess 26 is a cylindrical portion formed by setting the outer diameter of the LOx post 21 to be smaller than the outer diameter on the upstream side of the sleeve mounting portion 25, and extends to the end on the combustion chamber 3 side. Yes.

The sleeve 22 is formed in a cylindrical shape substantially coaxial with the LOx post 21 and is provided so as to cover the outer periphery of the LOx post 21. Specifically, the sleeve 22 has one end abutting against the sleeve mounting portion 25 and the other end connected to an injection surface 31 of the combustion chamber 3 described later (see also FIG. 1). The sleeve 22 covers the recess 26 provided on the outer peripheral surface of the LOx post 21 on the inner peripheral surface thereof with a gap, thereby forming a GH ₂ flow path 27 between the sleeve 22 and the LOx post 21. The GH ₂ channel 27 has an annular channel cross section. The sleeve 22 is formed with a plurality of introduction ports 28 extending from the outer peripheral surface thereof to the GH ₂ flow path 27. The sleeve 22 allows the introduction of the GH ₂ supplied by the supply device. uptake in GH ₂ flow path 27 through, toward the combustion chamber 3 from the GH ₂ passage 27 can be injected to the loaded GH ₂ between LOx post 21. Incidentally, with respect to the LOx passage 23 of the flow rate of LOx injected into the combustion chamber 3 is, for example, about 10 to 20 m / S, GH ₂ injected into the combustion chamber 3 from GH ₂ flow path 27 of LOx It is injected at a flow rate of about 10 times.

The combustion chamber 3 is one in which LOx and GH ₂ injected from the rocket injector 2 and atomized and mixed are combusted, and is defined by an injection surface 31 and a partition wall 32. The partition wall 32 of the combustion chamber 3 is formed in a cylindrical shape, and is provided with an injection surface 31 at one end and a nozzle 4 at the other end. The combustion chamber 3 is formed such that the inner diameter of the partition wall 32 is substantially constant on the injection surface 31 side and the radial cross-sectional area decreases toward the nozzle 4. The injection surface 31 of the combustion chamber 3 is connected to the sleeve 22 of the rocket injector 2 on the back side thereof, so that GH ₂ directed from the rocket injector 2 to the combustion chamber 3 is injected from the injection surface 31. (See also FIG. 1). Depending on the thrust of the rocket engine, hundreds of rocket injectors 2 are generally circumferential on the back side of the injection surface 31 of the combustion chamber 3 with respect to the central axis in the thrust direction of the rocket combustor 1. It arrange | positions so that it may become uniform in a direction. The nozzle 4 is formed continuously with the partition wall 32 of the combustion chamber 3 and communicates with the combustion chamber 3 inside. In addition, the nozzle 4 is formed in a conical shape that tapers toward the combustion chamber 3, thereby narrowing the outlet cross section of the combustion gas generated in the combustion chamber 3.

Rocket combustor configured as described above 1, LOx is injected into the combustion chamber 3 through the LOx passage 23 of rocket injector 2, GH ₂ into the combustion chamber 3 through the GH ₂ passage 27 Is injected. The LOx and GH ₂ injected into the combustion chamber 3 are atomized and mixed in the combustion chamber 3. The LOx and GH ₂ mixed in the combustion chamber 3 are ignited by the ignition means and then combusted in the combustion chamber 3. As a result, combustion gas is generated. And this combustion gas is injected from the combustion chamber 3 through the nozzle 4, and at this time, since the exit cross section of the combustion gas is narrowed down by this nozzle 4, the thrust by the injection of the combustion gas is improved and the thrust is obtained. be able to.

Here, in such a rocket combustor 1, due to the recent demand for higher efficiency of rocket engines, it is necessary to perform high-load combustion with a very high energy density locally in the combustion chamber. The generation of combustion vibrations that resonate with surface mode acoustics is a problem. In particular, in a combustor in which the inner diameter of the combustion chamber is constant, combustion vibration having a natural frequency as shown in the following equation (1) occurs, which becomes a problem during combustion.

f = (S _rn × C ₀ × 12) / (2π × R _c ) (1)

f; natural frequency C ₀ ; speed of sound R _c ; inner diameter of combustion chamber S _rn ; natural _{value of} surface mode

By the way, in a normal rocket injector, for example, a LOx post as an inner cylinder is made shorter than an outer cylinder sleeve so that a recess is provided at the end of the LOx post on the combustion chamber side. there is to promote the atomization and mixing by GH ₂ and collide.

However, in such a normal injector, the mixing of LOx and GH ₂ is disturbed in the recess at the outlet of the injector, and this causes a large pressure fluctuation in the recess having a small volume compared to the combustion chamber. The pressure fluctuation propagates into the LOx post and a part of GH ₂ enters and exits the upstream side of the LOx post, so that the LOx flow rate in the LOx post periodically fluctuates. As a result, the LOx There is a possibility that a standing wave having a natural frequency is excited in the LOx liquid column in the post, and the standing wave and the acoustic frequency of the surface mode of the combustion chamber resonate to amplify the combustion vibration.

Therefore, in the present embodiment, as shown in FIG. 1, the tip portion 21 a of the LOx post 21 is protruded from the injection surface 31 of the combustion chamber 3 toward the combustion chamber 3, so that the pressure fluctuation propagating into the LOx post 21 is generated. In addition, the GH ₂ is suppressed from flowing into the upstream side in the LOx post 21 and the amplification of combustion vibration in the combustion chamber 3 due to the standing wave from the rocket injector 2 is suppressed.

Specifically, the LOx post 21 is provided such that the tip 21 a protrudes toward the combustion chamber 3 from the injection surface 31 of the combustion chamber 3. Ejection face 31 of the combustion chamber 3, as described above, the sleeve 22 is connected to the back side, which is a surface GH ₂ passage 27 GH ₂ which has been flowing is injected toward the combustion chamber 3.

FIG. 4 is a schematic diagram showing an example of a result of numerical fluid analysis, so-called CFD analysis, for the rocket combustor 1 to which the rocket injector 2 according to the present embodiment is applied. In this figure, the CFD analysis results at predetermined time intervals (Δt = 0.24 ms) of the portion indicated by the dotted line in FIG. 1 are arranged in time series. In the figure, the hatched area is the LOx area, and the other areas are areas other than LOx (GH ₂ , a mixture of atomized GH ₂ and LOx, etc.).

By providing the tip end portion 21a of the LOx post 21 so as to protrude from the injection surface 31 of the combustion chamber 3 toward the combustion chamber 3, the LOx and GH ₂ are, for example, the conventional LOx post described above as shown in FIG. Since the mixing is performed in the combustion chamber 3 having a larger volume than the recess provided at the end portion on the combustion chamber side, the pressure fluctuation due to the disturbance of the mixing of LOx and GH ₂ is suppressed. As a result, the pressure fluctuation propagating to the LOx passage 23 in the LOx post 21 is reduced, and a part of GH ₂ injected from the GH ₂ passage 27 is prevented from flowing into the upstream side of the LOx passage 23. Is done.

That is, by suppressing a part of GH _{2 from} entering and exiting the upstream side in the LOx flow path 23, the LOx flow rate in the LOx flow path 23 does not periodically change, and as a result, Since the standing wave of the natural frequency is suppressed in the LOx liquid column of the LOx flow path 23, the standing wave from the rocket injector 2 and the acoustic frequency of the surface mode of the combustion chamber 3 resonate. Neither does it amplify the combustion vibration.

Here, as shown in FIG. 1, the LOx post 21 has a protruding amount L of the tip 21a from the injection surface 31 that is at least larger than 0, and an outer diameter D (axial direction) of the tip 21a of the LOx post 21. The projected area is set to 1.0 times or less. More preferably, the protrusion amount L of the distal end portion 21a is set to 0.5 times or less of the outer diameter D. Thus, by setting the protrusion amount L of the tip 21a from the ejection surface 31 to [0 <L ≦ 1.0 × D], more preferably [L≈0.5], LOx and GH ₂ When the LOx and GH ₂ are mixed and combusted in the combustion chamber 3, the tip portion 21 a of the LOx post 21 is prevented from being burned by this combustion. Is done.

Thus, in the rocket injector 2 and the rocket combustor 1 of the present embodiment, the combustion chamber 3 in which LOx and GH ₂ are mixed and combusted, and the cylinder is formed and provided inside. LOx can be injected from the LOx flow path 23 toward the combustion chamber 3, and a tip portion 21 a protrudes from the injection surface 31 of the combustion chamber 3 from which GH ₂ is injected to the combustion chamber 3 side.

Therefore, the injection surface 31 of the combustion chamber 3 on which GH ₂ is injected from the tip 21 a of the LOx post 21 that is capable of injecting LOx toward the combustion chamber 3 from the LOx flow path 23 that is formed in a cylindrical shape. By projecting more toward the combustion chamber 3 side, LOx and GH ₂ are mixed in the combustion chamber 3 having a relatively large volume, so that pressure fluctuation due to disturbance of mixing of LOx and GH ₂ is suppressed. As a result, the pressure fluctuation propagating into the LOx flow path 23 is reduced and the GH ₂ is suppressed from flowing into the upstream side of the LOx flow path 23. As a result, the natural frequency in the LOx flow path 23 is constant. Since the excitation of the wave is prevented, the amplification of the combustion vibration in the combustion chamber 3 caused by the standing wave from the rocket injector 2 can be suppressed.

  Further, for example, in order to suppress the occurrence of the surface mode in the combustion chamber 3, the combustion gas having a higher temperature than that in the case where a baffle blade (Baffle Blade) and a baffle hub (Baffle Hub) are mounted in the combustion chamber 3. Therefore, the structure of the rocket combustor 1 is not complicated, and the cooling effect of the baffle blade and the baffle hub does not reduce the combustion efficiency. . Furthermore, the weight of the rocket combustor 1 is not increased by mounting the baffle blade and the baffle hub. That is, according to the rocket injector 2 and the rocket combustor 1 of this embodiment, it is possible to contribute to higher efficiency of the rocket engine.

Further, in the rocket injector 2 and the rocket combustor 1 of the present embodiment, the GH ₂ flow between the LOx post 21 and the cylindrical shape is formed so as to cover the outer periphery of the LOx post 21 and is connected to the injection surface 31. A sleeve 22 capable of injecting GH ₂ from the passage 27 toward the combustion chamber 3 is provided. Therefore, the GH ₂ flow path 27 can be formed between the LOx post 21 and the sleeve 22 so as to cover the LOx post 21, and thereby the fuel is injected from the inside of the LOx post 21 toward the combustion chamber 3. LOx and GH ₂ injected toward the combustion chamber 3 from the outside of the LOx post 21 can be reliably brought into contact with each other and mixed.

Further, in the rocket injector 2 and the rocket combustor 1 of the present embodiment, the LOx post 21 has a protruding amount L of the tip portion 21a from the injection surface 31 that is at least larger than 0, and is outside the LOx post 21. It is set to 1.0 times or less of the diameter D. Therefore, the tip end portion 21a of the LOx post 21 protrudes toward the combustion chamber 3 side from the injection surface 31 on which GH ₂ is injected, thereby reliably suppressing pressure fluctuations caused by mixing disturbance of LOx and GH ₂ and the combustion chamber. When the LOx and GH ₂ are mixed and combusted in the combustion chamber 3, it is possible to prevent the tip portion 21a of the LOx post 21 from being burned by this combustion. As a result, the life of the rocket injector 2 and the rocket combustor 1 can be extended.

  FIG. 5 is a schematic cross-sectional view showing a schematic configuration of a rocket injector according to Embodiment 2 of the present invention. The rocket injector according to the second embodiment has substantially the same configuration as the rocket injector according to the first embodiment, but the inner shape of the inner cylinder tip is different from the rocket injector according to the first embodiment. In addition, about the structure, effect | action, and effect which are common in Example 1, while overlapping description is abbreviate | omitted as much as possible, the same code | symbol is attached | subjected.

  As shown in FIG. 5, the LOx post 21 as the inner cylinder of the rocket injector 202 according to the second embodiment is formed so that the inner diameter R <b> 1 of the tip 21 a decreases toward the combustion chamber 3. Specifically, the tip end portion 21a of the LOx post 21 of the present embodiment has a post-inside tapered surface 229 formed on the inner surface thereof. The post post taper surface 229 is formed by gradually increasing the wall thickness of the LOx post 21 toward the combustion chamber 3 at the tip 21a. As a result, the radial sectional area of the LOx flow path 23 formed inside the LOx post 21 gradually decreases toward the combustion chamber 3, and the LOx flow path 23 is narrowed in the axial direction of the LOx post 21. .

  In the rocket injector 202 configured as described above, the flow velocity of LOx at the wall of the LOx flow path 23 tends to be low due to the post-inner tapered surface 229 provided inside the tip portion 21a of the LOx post 21. Is increased.

Thus, in the rocket injector 202 of the present embodiment, the tip 21 a of the LOx post 21 has an inner diameter R 1 that decreases toward the combustion chamber 3. Therefore, since the flow velocity of LOx flowing near the inner wall surface at the tip 21a of the LOx post 21 is increased, it is possible to prevent a region where the flow velocity of LOx is low in the LOx post 21 from being formed, and Since the flow velocity can be made uniform, the backflow of GH ₂ to the LOx flow path 23 can be reliably prevented.

  FIG. 6 is a schematic cross-sectional view showing a schematic configuration of a rocket injector according to Embodiment 3 of the present invention. The rocket injector according to the third embodiment has substantially the same configuration as the rocket injector according to the second embodiment, but the inner shape of the tip of the outer cylinder is different from the rocket injector according to the second embodiment. In addition, about the structure, effect | action, and effect which are common in Example 2, while omitting the overlapping description as much as possible, the same code | symbol is attached | subjected.

As shown in FIG. 6, the tip 322 a of the GH ₂ flow path 27 of the rocket injector 302 according to the third embodiment is formed so that the outer diameter R < _b > ₂ becomes smaller toward the combustion chamber 3. In other words, the outer diameter R2 of the GH ₂ flow path 27 formed in an annular shape is the inner diameter of the sleeve 22. That is, the sleeve 22 as an outer cylinder is formed so that the inner diameter of the tip end portion 322 a becomes smaller toward the combustion chamber 3. Specifically, the tip end portion 322a has a sleeve inner tapered surface 330 formed on the inner surface thereof. The sleeve inner tapered surface 330 is formed by gradually increasing the thickness of the wall surface of the sleeve 22 toward the combustion chamber 3 at the distal end portion 322a. As a result, the radial cross-sectional area of the GH ₂ flow path 27 formed in an annular cross section inside the sleeve 22 gradually decreases toward the combustion chamber 3, and the GH ₂ flow path 27 is the axis of the sleeve 22. Squeezed in the direction.

In rocket injector 302 constructed as described above, at the distal end 322a, the sleeve tapered surface 330 provided on the inside, axial GH ₂ sleeve 22 through the GH ₂ passage 27, i.e., LOx Injected in the direction of LOx injected from the post 21.

Thus, in the rocket injector 302 of this embodiment, the outer diameter R2 of the tip 322a of the GH ₂ flow path 27 decreases toward the combustion chamber 3. Therefore, since GH ₂ injected from the GH ₂ flow passage 27 between the LOx post 21 and the sleeve 22 is injected toward the LOx ejected from LOx post 21 inside the LOx flow path 23, GH ₂ and LOx As a result, the atomization is promoted by the collision effect, and GH ₂ and LOx can be mixed more efficiently.

  FIG. 7 is a schematic cross-sectional view showing a schematic configuration of a rocket injector according to Embodiment 4 of the present invention. The rocket injector according to the fourth embodiment has substantially the same configuration as that of the rocket injector according to the third embodiment, but the outer shape of the tip of the inner cylinder is different from the rocket injector according to the third embodiment. In addition, about the structure, effect | action, and effect which are common in Example 3, while overlapping description is abbreviate | omitted as much as possible, the same code | symbol is attached | subjected.

As shown in FIG. 7, the tip 322 a of the sleeve 22 of the rocket injector 402 according to the fourth embodiment is formed so that the inner diameter R <b> 3 becomes smaller toward the combustion chamber 3. In other words, the inner diameter R3 of the GH ₂ flow path 27 formed in an annular shape is the outer diameter of the LOx post 21. That is, the LOx post 21 as an inner cylinder is formed so that the outer diameter of the tip 21 a becomes smaller toward the combustion chamber 3. Specifically, the tip 21a of the LOx post 21 of this embodiment is formed with a bent portion 431 in place of the post-internal tapered surface 229 (see FIG. 5) of the second embodiment. In the bent portion 431, the wall thickness of the wall surface of the LOx post 21 does not change at the distal end portion 21 a, but the wall surface is bent in the axial direction of the LOx post 21, so The inner diameter R3 of the GH ₂ flow path 27 is also reduced toward the combustion chamber 3 while decreasing toward the combustion chamber 3. Thereby, the radial cross-sectional area of the LOx flow path 23 formed inside the LOx post 21 gradually decreases toward the combustion chamber 3, and the LOx flow path 23 is narrowed in the axial direction of the LOx post 21. Further, the radial cross section of the GH ₂ flow path 27 formed in an annular cross section inside the sleeve 22 gradually narrows in the axial direction toward the combustion chamber 3.

In rocket injector 402 configured as described above, the bent portion 431 provided at the distal end portion 21a of the LOx post 21, the axial direction of the GH ₂ sleeve 22 through the GH ₂ passage 27, i.e., LOx post 21 It is reliably injected toward the direction of LOx injected from.

Thus, in the rocket injector 402 of this embodiment, the inner diameter R3 of the tip 322a of the GH ₂ flow path 27 becomes smaller toward the combustion chamber 3. Therefore, it is possible to more reliably ejected toward the LOx the GH ₂ injected from the GH ₂ flow passage 27 between the LOx post 21 and the sleeve 22, further improving the efficiency of mixing of the GH ₂ and LOx can do.

  The rocket injector and the rocket combustor according to the present invention suppress amplification of combustion vibration in the combustion chamber caused by the standing wave from the rocket injector. It can also be applied to a combustor.

It is a typical sectional view showing a schematic structure of a rocket injector concerning Example 1 of the present invention. It is a typical perspective view which shows schematic structure of the combustor for rockets which applied the rocket injector which concerns on Example 1 of this invention. It is a typical perspective view which shows schematic structure of the rocket injector which concerns on Example 1 of this invention. It is a schematic diagram which shows an example of the CFD analysis result of the combustor for rockets which applied the injector for rockets which concerns on Example 1 of invention. It is typical sectional drawing which shows schematic structure of the rocket injector which concerns on Example 2 of this invention. It is typical sectional drawing which shows schematic structure of the rocket injector which concerns on Example 3 of this invention. It is typical sectional drawing which shows schematic structure of the rocket injector which concerns on Example 4 of this invention.

Explanation of symbols

1 Rocket combustor 2, 202, 302, 402 Rocket injector 3 Combustion chamber 4 Nozzle 21 LOx post (inner cylinder)
21a Tip 22 Sleeve (outer cylinder)
23 LOx channel (oxidant channel)
24 Orifice 25 Sleeve mounting portion 26 Recessed portion 27 GH ₂ flow path (fuel flow path)
28 Inlet 31 Injection surface 32 Bulkhead 229 Post-inner taper surface 322a Tip portion 330 Sleeve inner taper surface 431 Bending portion D LOx post outer diameter L Tip protrusion amount R1 LOx post tip inner diameter R2 GH ₂ Flow path tip outer diameter R3 GH ₂ flow path tip inner diameter

Claims (7)

A combustion chamber in which an oxidant and fuel can be mixed and burned,
The oxidant can be injected into the combustion chamber from an oxidant flow path formed in a cylindrical shape and provided at the tip from the injection surface of the combustion chamber where the fuel is injected. And an inner tube protruding to
Rocket injector. The inner cylinder is set such that a protruding amount of the tip portion from the injection surface is at least larger than 0 and 1.0 times or less of an outer diameter of the inner cylinder.
The rocket injector according to claim 1. The tip of the inner cylinder has an inner diameter that decreases toward the combustion chamber.
The rocket injector according to claim 1 or 2. An outer cylinder that covers the outer periphery of the inner cylinder, is formed in a cylindrical shape, is connected to the injection surface, and is capable of injecting the fuel from the fuel flow path between the inner cylinder and the combustion chamber. Features
The rocket injector according to any one of claims 1 to 3. The tip of the fuel flow path has an outer diameter that decreases toward the combustion chamber,
The rocket injector according to claim 4. The tip of the fuel flow path has an inner diameter that decreases toward the combustion chamber,
The rocket injector according to claim 4 or 5. A combustion chamber in which oxidant and fuel are mixed and burned to generate combustion gas;
The oxidant can be injected into the combustion chamber from an oxidant flow path formed in a cylindrical shape and provided at the tip from the injection surface of the combustion chamber where the fuel is injected. An inner cylinder projecting from the inner cylinder, and a cylindrical shape covering the outer periphery of the inner cylinder, connected to the injection surface, and capable of injecting the fuel from the fuel flow path between the inner cylinder and the combustion chamber A plurality of injectors having an outer cylinder;
A nozzle that is connected to the combustion chamber and raises thrust by narrowing an outlet of the combustion gas injected from the combustion chamber;
Rocket combustor.

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