JP2002004947A - Blow-back controlling mechanism in high altitude combustion test equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blow-back controlling mechanism in high altitude combustion test equipment capable of reducing the damage and the melting loss of an engine, a measuring instrument or the like, and reducing the cost by lowering a flow velocity and a flow rate of the blow-back generated in cutting off the engine. SOLUTION: In the high altitude combustion test equipment executing the combustion test of the engine 1 by jetting a combustion gas 5 of the rocket engine 1 in a test chamber 2 from a nozzle skirt 4 into a cylindrical body 3, an openable and closeable hatch 7 is mounted between the nozzle skirt 4 of the engine 1 and the cylindrical body 3, and a vacuum tank 10 is communicated with an outer peripheral part of the cylindrical body 3 through an opening and closing valve 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blow-back suppression mechanism of a high-altitude combustion test facility for suppressing blow-back that is generated specifically during a high-altitude combustion test of a rocket engine on the ground.

[0002]

2. Description of the Related Art FIG. 7 shows the configuration of a conventional general high altitude combustion test facility (HATS). During the steady combustion shown in FIG. 7A, the pressure in the test chamber (low-pressure chamber) 53 is reduced by the ejector 52 that ejects the high-speed steam gas 51 on the equipment side, but the engine 54 is ignited and started. Then, an ejector effect (self-ejector) is further generated by the combustion gas 55, and the degree of vacuum in the test chamber 53 is further increased. Therefore, when the engine 54 is cut off (combustion stopped), as shown in FIG. 7B, the ejector effect by the engine combustion gas 55 is instantaneously lost, and the combustion gas 55 is transferred to the low-pressure test chamber 53 as shown by the arrow. It comes back. This is called blowback 56.

[0003]

However, in the above-described conventional high-altitude combustion test facility, the engine 54 and the measuring device 57 may be damaged by the blowback 56 at the time of cut-off of the engine 54. In particular, the end of the nozzle skirt 58 located on the upstream side is highly likely to be damaged, melted, or the like, and has a problem in durability, resulting in an increase in cost due to replacement of parts or use of a dummy nozzle skirt. It has the defect of.

The present invention has been made in view of the above circumstances, and an object of the present invention is to reduce the flow rate and flow rate of blowback generated at the time of engine cutoff, thereby damaging or melting an engine, measuring equipment, or the like. An object of the present invention is to provide a blow-back suppressing mechanism in a high-altitude combustion test facility capable of reducing loss and the like and reducing costs.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the prior art, according to the present invention, a high altitude test is performed in which a combustion test of an engine in a test chamber is injected from a nozzle into a cylinder to perform a combustion test of the engine. In the combustion test facility, an openable and closable hatch is provided between the nozzle of the engine and the cylindrical body, and a vacuum chamber communicating with the hatch is provided on an outer peripheral portion of the cylindrical body via an open / close valve.

Further, according to the present invention, the hatch is formed of upper and lower divided hatch pieces, and is provided at an upstream end of the cylindrical body, and when the engine is cut off, the hatch pieces are moved up and down to blow. The back channel is configured to expand.

Further, according to the present invention, the hatch is provided so as to be movable in a plurality of openings formed in the outer peripheral surface of the cylindrical body, and when the engine is cut off, the hatch is moved to open the opening. The blowback flow path is configured to branch off. Moreover, the present invention provides the above-described cylinder, wherein the hatch is formed in a ring shape and is provided movably on an outer peripheral surface of an upstream end portion of the cylindrical body. An opening formed in the outer peripheral surface of the body is opened, so that the flow path of the blowback is branched. Further, the present invention is characterized in that the hatch is movably provided in a plurality of openings in an end face of a flange formed on an outer periphery of an upstream end of the cylindrical body. It is configured such that the part is opened and the flow path of the blowback branches off.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on illustrated embodiments. Here, FIG. 1 is a basic configuration diagram of a high-altitude combustion test facility in which blowback suppression measures are taken according to an embodiment of the present invention, and FIGS. 2 to 5 are hatches of various types provided in the high-altitude combustion test facility of the present embodiment. FIG. 6 is a timing chart of opening the hatch and the valve. The high altitude combustion test facility according to the embodiment of the present invention is used for the high altitude combustion test of the rocket engine 1 on the ground.
A test chamber (low-pressure chamber) 2 in which a rocket engine 1 for performing a combustion test is installed, and a tubular body (diffusion cylinder) 3 whose upstream end 3a is connected to the test chamber 2 are provided.

A nozzle skirt 4 is provided at the rear end (downstream end) of the rocket engine 1 as shown in FIG. The combustion gas 5 is injected. A hatch 7 is provided between the nozzle skirt 4 and the cylindrical body 3 to open and close a hatch 7 for releasing a blowback 6 of the combustion gas 5 flowing backward into the test chamber 2 to the outside of the nozzle skirt 4. On the other hand, the cylindrical body 3 extends in a horizontal direction from one side surface of the housing 2a constituting the test chamber 2, and jets a high-speed steam gas 8 during steady combustion into a downstream portion of the upstream end 3a. An ejector 9 is provided, and the ejector 9 reduces the pressure in the test chamber 2. Further, a vacuum chamber 10 communicating with the inside of the cylindrical body 3 is provided via an opening / closing valve 11 on an outer peripheral portion located near the upstream end 3a of the cylindrical body 3. The structure is such that the blowback 6 is sucked into the airbag. That is, the blowback suppression mechanism of the present embodiment is mainly configured by the vacuum chamber 10 including the hatch 7 and the opening / closing valve 11.

As the hatch 7 of the present embodiment, a hatch 7a of an enlarged flow path as shown in FIG. 2 and a hatch 7b to 7d of a branched flow path as shown in FIGS. 3 to 5 are provided. . That is, as shown in FIG. 2, the enlarged channel type hatch 7 a is formed by semi-circular hatch pieces 12 and 13 having an upper and lower divided structure, and is provided at the tip of the upstream end 3 a of the cylindrical body 3. In addition, sealing members 14 for preventing the combustion gas 5 from leaking when the hatch 7a is closed are fixed to the opposing overlapping portions of the hatch pieces 12 and 13, respectively. Moreover,
Actuators 15 each having an extendable operating rod 15a are provided between the outer peripheral portions of the hatch pieces 12, 13 and the upper and lower inner wall surfaces of the housing 2a. Piece 12,1
3 is opened and closed by moving it up and down, so that the flow path of the blowback 6 expands and the flow path of the combustion gas 5 becomes constant. The actuator 1
The number of arrangements 5 is determined according to the shape and weight of the hatch 7.

As shown in FIG. 3, the flow path branch type hatch 7b is movably provided in a plurality of openings 16 formed on the outer peripheral surface of the upstream end 3a of the tubular body 3. A hatch 7b is provided on the outer periphery of the
A sealing member 14 is fixed to prevent the combustion gas 5 from leaking in the closed state. A telescopic operating rod 1 is provided between each hatch 7b and the upper and lower inner wall surfaces of the housing 2a.
The two actuators 15 having the actuator 5a are installed at intervals in the axial direction, and the opening 16 is opened and closed by moving the hatch 7b in and out by the expansion and contraction of the operating rod 15a. The passage is branched so that the flow path of the combustion gas 5 is constant.

As shown in FIG. 4, the other flow path branching type hatch 7c is formed in a ring shape having an inner diameter substantially equal to the outer diameter of the cylindrical body 3 and an outer diameter larger than that of the cylindrical body 3. It is provided movably on the outer peripheral surface of the upstream end 3a of the tubular body 3. On the other hand, an opening 17 is formed on the outer peripheral surface of the upstream end 3a of the tubular body 3, and the inner periphery of the hatch 7c or the periphery of the opening 17 is provided with the combustion gas 5 in the closed state of the hatch 7c. A sealing member 14 is fixed to prevent leakage. A pair of upper and lower actuators 15 having telescopic operating rods 15a are respectively provided between the hatch 7c and the inner wall surface on the downstream side of the housing 2a, and the hatch 7c is moved along the axial direction by the expansion and contraction of the operating rod 15a. The opening 17 is opened and closed by moving the blow-back 6, the flow path of the blowback 6 is branched, and the flow path of the combustion gas 5 is configured to be constant.

Further, another flow path branching type hatch 7d is:
As shown in FIG. 5, a plurality of openings 19 pierced at intervals in the circumferential direction are provided on the upstream end surface of the flange portion 18 so as to be movable, and the flange portion 18 is located on the upstream side of the cylindrical body 3. It is formed to protrude on the outer periphery of the end 3a. Moreover,
The outer periphery of the hatch 7d or the periphery of the opening 19 has a hatch 7
A sealing member 14 for preventing the combustion gas 5 from leaking in the closed state of d is fixed. A telescopic operating rod 15a is provided between the hatch 7d and the outer peripheral surface of the cylindrical body 3.
And a pair of upper and lower actuators 15 each having a hatch.
The opening 19 is opened and closed by moving d in the radial direction, the flow path of the blowback 6 is branched, and the flow path of the combustion gas 5 is configured to be constant.

Such a hatch 7 and an opening / closing valve 11
Are controlled by a controller (not shown), and are opened and closed at the timing shown in FIG. That is, combustion of the rocket engine 1 is started when the hatch 7 and the opening / closing valve 11 are closed, and the hatch 7 and the opening / closing valve 11 are opened when the engine is cut off. The opening timing X seconds from the engine cutoff to the opening of the hatch 7 and the opening / closing valve 11 is adjusted according to the actual engine characteristics.

On the other hand, an opening 21 for introducing the atmosphere 20 into the test chamber 2 is provided on an upper wall surface of the housing 2a of the test chamber 2 above the rocket engine 1, as shown in FIG. The opening 21 is provided with an upper hatch 22 that can be opened and closed, and the upper hatch 22 is configured to open and close the opening 21. By opening the opening 21 and introducing the atmosphere 20, the upper hatch 22 does not cause the nozzle skirt 4 to buckle (a phenomenon in which the external pressure becomes larger than the inside of the nozzle skirt and the nozzle skirt 4 is dented inward). The pressure in the test chamber 2 is increased to a certain extent, and the flow rate of the blowback 6 is reduced.

Next, a procedure for performing a high-altitude combustion test of the rocket engine 1 using the high-altitude combustion test facility according to the embodiment of the present invention will be described. First, hatch 7 and open / close valve 1
When the rocket engine 1 is closed, the rocket engine 1 installed in the test chamber 2 is ignited to start burning. During this steady combustion, FIGS. 2A, 3A, 4A and 5
As shown in FIG.
5a is in an extended state, hatches 7a to 7d are closed, and the conventional shape is maintained. Therefore, the combustion gas 5 of the rocket engine 1 is injected from the nozzle skirt 4 into the cylindrical body 3 through a certain flow path, and a combustion test is performed.

On the other hand, when the engine cutoff for stopping the combustion of the rocket engine 1 is performed, the combustion gas 5 flows backward from the cylindrical body 3 into the test chamber 2 as shown in FIG. Therefore, FIG. 2 (B), FIG. 3 (B), FIG.
As shown in FIG. 5B and FIG.
Is operated to bring the operating rod 15a into a contracted state, open the hatches 7a to 7d to expand the flow path of the blowback 6, or branch the flow path of the blowback 6, and open the open / close valve 11. Then blowback 6
1 is sucked from the tubular body 3 through the opening / closing valve 11 into the vacuum chamber 10 and escaped as shown by the arrow in FIG. Further, as shown by arrows in FIG. 1, a part of the blowback 6 is expanded and branched by open hatches 7 a to 7 d and guided to the outside of the nozzle skirt 4 of the rocket engine 1, and the inside of the housing 2 a The flow rate of the blowback 6 flowing along the wall surface and returning to the engine section in the test chamber 2 decreases, and the gas flow rate directly hitting the rocket engine 1 (particularly the end of the nozzle skirt 4) decreases. At this time, when the upper hatch 22 is opened, the atmosphere 20 enters the test chamber 2 through the opening 21 and flows in the direction opposite to the direction in which the blowback 6 flows, so that the flow velocity of the blowback 6 is reduced.

In the high-air combustion test facility according to the embodiment of the present invention, a blowback suppressing mechanism constituted by a hatch 7, a vacuum chamber 10, and an opening / closing valve 11 is provided at a predetermined position in the test chamber 2 and the cylindrical body 3. Therefore, even when the combustion gas 5 flows back into the low-pressure test chamber 2 at the time of engine cutoff, the blowback 6 is sucked into the vacuum chamber 10 by opening the hatch 7 and the opening / closing valve 11, and the nozzle skirt 4 The structure has a structure in which the gas flows directly to the outside of the nozzle skirt 4 by reducing the flow rate and the flow rate of the blowback 6 by expanding and branching the flow path. Can be. Moreover,
In the high-altitude combustion test facility of the present embodiment, the upper hatch 22 for opening and closing the opening 21 is provided on the upper wall surface of the housing 2a. The flow rate of the blowback 6 can be further reduced by adjusting the pressure in the test chamber 2.

The embodiments of the present invention have been described above.
The present invention is not limited to the embodiments described above, and various modifications and changes can be made based on the technical idea of the present invention. For example, the hatch 7a in the above-described embodiment
7 to 7d, as long as the flow velocity and the flow rate of the blowback 6 can be surely reduced, a hatch of an enlarged flow path type or a branched flow path type having another structure may be used.

[0020]

As described above, the blow-back suppressing mechanism according to the present invention is a high-altitude combustion test facility for performing a combustion test of an engine by injecting combustion gas of the engine in a test chamber from a nozzle into a cylindrical body. A hatch that can be opened and closed is provided between the nozzle and the cylindrical body, and a vacuum chamber that communicates with the outer periphery of the cylindrical body is provided through an open / close valve. By opening the open / close valve, the flow rate and flow rate of the blowback, which is the backflow of combustion gas, can be reliably reduced, and as a result, damage and erosion of the engine, especially the nozzle skirt and measuring equipment, etc. can be reduced. Thus, it is possible to reduce equipment costs. Therefore, in the high-altitude combustion test equipment provided with the blowback suppression mechanism of the present invention, a flight-type thin nozzle skirt, which could not be performed by the conventional equipment, can be used to perform a combustion test in the state of a complete flight product. And further soundness of the flight nozzle skirt can be confirmed. Moreover, in the high-altitude combustion test facility of the present invention, there is no need to use a dummy nozzle skirt, so that cost performance can be improved.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a basic configuration of a high-air combustion test facility provided with a blow bag suppressing mechanism according to an embodiment of the present invention.

FIGS. 2A and 2B show a configuration of a hatch of an enlarged flow path type provided in the high-altitude combustion test facility of the present embodiment, wherein FIG. 2A is a conceptual diagram of a hatch during steady combustion, and FIG. It is a conceptual diagram of a hatch.

FIGS. 3A and 3B show a configuration of a flow path branch type hatch provided in the high-altitude combustion test facility of the present embodiment. FIG. 3A is a conceptual diagram of the hatch during steady combustion, and FIG. It is a conceptual diagram of a hatch.

FIGS. 4A and 4B show the configuration of another flow path branch type hatch provided in the high-altitude combustion test facility of the present embodiment, wherein FIG. 4A is a conceptual diagram of the hatch during steady combustion, and FIG. It is a conceptual diagram of the hatch at the time.

5A and 5B show still another configuration of a flow path branch type hatch provided in the high-altitude combustion test facility of the present embodiment, and FIG.
3 is a conceptual diagram of a hatch during steady combustion, and FIG. 3B is a conceptual diagram of a hatch at an engine cutoff.

FIG. 6 is a diagram showing the timing of hatches and valves provided in the high-altitude combustion test facility of the present embodiment.

FIG. 7 shows a configuration of a conventional high-altitude combustion test facility,
(A) is a conceptual diagram of a state during steady combustion, and (B) is a conceptual diagram of a state at the time of engine cutoff.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rocket engine 2 Test chamber 3 Cylindrical body 4 Nozzle skirt 5 Combustion gas 6 Blowback 7 Hatch 10 Vacuum tank 11 Opening / closing valve 15 Actuator 16, 17, 19 Opening 18 Flange 20 Atmosphere 21 Opening 22 Upper hatch

Claims (5)

[Claims] 1. A high altitude combustion test facility for injecting combustion gas of an engine in a test chamber from a nozzle into a cylinder to perform a combustion test of the engine, wherein the apparatus can be opened and closed between the nozzle of the engine and the cylinder. A blow-back suppressing mechanism in a high-altitude combustion test facility, wherein a hatch is provided, and a vacuum chamber communicating with the outer periphery of the cylindrical body is provided via an opening / closing valve. 2. The hatch is formed of upper and lower divided hatch pieces and is provided at an upstream end of the cylindrical body. When the engine is cut off, the hatch pieces are moved up and down to flow blowback. The blowback suppressing mechanism in the high-altitude combustion test facility according to claim 1, wherein the path is configured to expand. 3. The hatch is provided movably in a plurality of openings formed in the outer peripheral surface of the cylindrical body, and when the engine is cut off, the hatch is moved to open the openings, and a blowback is provided. The blow-back suppressing mechanism in the high-altitude combustion test facility according to claim 1, wherein the flow path is configured to branch off. 4. The hatch is formed in a ring shape and movably provided on an outer peripheral surface of an upstream end portion of the tubular body,
At the time of engine cut-off, the hatch is moved to the downstream side to open an opening formed in the outer peripheral surface of the tubular body, and a flow path of a blowback is configured to branch off. 2. A blow-back suppressing mechanism in the high altitude combustion test facility according to 1. 5. The hatch is provided movably at a plurality of openings in an end face of a flange formed on an outer periphery of an upstream end of the tubular body, and moves the hatch at the time of engine cutoff to move the hatch. 2. The blow-back flow path is branched to open a part.
4. A blowback suppression mechanism in the high-altitude combustion test facility according to item 1.