JP3994284B2 - Valve for pulse detonation engine - Google Patents

Description

  The present invention relates to a valve for a pulse detonation engine, and more particularly, a novel valve for a pulse detonation engine that can reduce fatigue failure due to combustion pressure oscillation in the pulse detonation engine and can improve thrust in the high altitude of the pulse detonation engine. About.

  The detonation phenomenon is a supersonic combustion phenomenon with a vertical shock wave in front of the combustion wave, and the generated energy density is larger than that of normal subsonic combustion (defragmentation), and high-temperature and high-pressure combustion gas is generated. In recent years, as the cell structure of detonation waves, defragmentation / detonation transition conditions, time, etc. have been elucidated, researches have been conducted to control and effectively use them (Non-Patent Document 1 and Non-Patent Document 1). Reference 2). The pulse detonation engine is an engine that uses detonation in the combustion process, and as schematically shown in FIGS. 5A to 5C, a mixed gas (fuel and oxidant) is supplied to the combustor (combustion tube) 31. This is an intermittent combustion engine that repeats filling, combustion, and exhaust in a cycle of about 10 Hz to 100 Hz. After the mixed gas is supplied into the combustor 31 during the filling process, ignition occurs at the closed end 32 of the combustor, and the combustion wave is defragmented (subsonic combustion) while propagating from the closed end to the open end 33. Transition from wave to detonation (supersonic combustion) wave. Once the detonation wave 35 is formed, the combustion gas generated by the combustion becomes high temperature and high pressure, and a large thrust is generated at the closed end 32. When the detonation wave 35 reaches the opening end 33, the exhaust process starts, and the combustion gas is exhausted until it matches the external pressure.

  As a pulse detonation engine using such a detonation phenomenon, for example, a pulse detonation engine combined with a turbofan jet engine has been proposed (see Patent Document 1). Since the pulse detonation engine is an intermittent combustion engine as described above, a mixed gas is supplied and controlled to each combustor in order to continuously operate a plurality of combustors in an effective cycle and continuously generate thrust. The combustor inlet valve is required to open and close at a high speed at an accurate timing, and a pulse detonation engine having a conventional rotating disk valve has been proposed as a response to such a demand (for example, Patent Documents 2 and 3). reference).

JP 2001-355515 A US Pat. No. 5,353,588 US Pat. No. 5,473,885 "DETONATION, next generation engine war breaks out" (Popular Science magazine, November 2003 issue) AIAA-95-3577 "A Rotary Valve Multiple Pulse Detonation Engine (RVMPDE)"

  Since the pulse detonation engine repeats combustion at a high speed as described above, the inlet valve that supplies the mixed gas to the combustor is required to have high-speed opening and closing characteristics, and is subject to vibration and repeated stress due to combustion, so that fatigue failure tends to occur There is a problem. Conventionally proposed rotary disk valves are satisfactory in terms of high-speed opening and closing, but are still unsatisfactory in terms of reducing fatigue failure because they are susceptible to repeated stress due to detonation waves. On the other hand, the conventional pulse detonation engine is equipped with an open / close valve for controlling the mixed gas supply at the combustor inlet to enable the mixed gas filling / combustion / exhaust cycle, but the combustor outlet is directly connected to the nozzle. It has an open air structure. For this reason, since the combustor and the outside air are not shut off during the filling process, the filling pressure and density are only slightly higher than the outside air pressure. Therefore, the thrust density of the combustor (generated thrust / combustor cross-sectional area) is limited by the external atmospheric pressure, and becomes lower as the flying state becomes higher when applied to an aircraft engine. Because of this factor, the use of a pulse detonation engine is considered inappropriate for a supersonic air-breathing engine flying in the high sky, and it does not take advantage of the high specific thrust.

  Therefore, the problem to be solved by the present invention is to solve the problems of the above-mentioned conventional pulse detonation engine, excellent in high-speed opening and closing, and less susceptible to fatigue failure due to vibration and repeated stress due to combustion, Furthermore, to provide a valve for a pulse detonation engine that can achieve high thrust density even in a supersonic air suction type engine that flies at a high altitude by increasing the pressure and density in the process of filling the mixed gas into the combustor. It is.

  As a result of various studies to solve the above-mentioned problems, the present inventor has conceived that the supply valve is a cylindrical rotary type as a means for reducing the high-speed response of the valve and the influence of pressure vibration due to combustion, and As a means to improve the thrust density at high altitude of the pulse detonation engine, the working fluid is made to fill the detonation process without filling the combustor outlet in the mixed gas filling process without causing high-pressure and high-density expansion. It has been found out that it is possible to achieve the present invention.

  That is, the valve for a pulse detonation engine of the present invention that solves the above problems is a valve of a pulse detonation engine that obtains an output by detonating a mixed gas of an oxidant and a fuel in a combustor, and one end of the oxidant intake side. Is formed in a cylindrical structure in which the other end is closed, and a plurality of supply holes are provided symmetrically with respect to the central axis on a part of the cylindrical surface, and are arranged to be rotationally driven at the combustor inlet. It is characterized by comprising a cylindrical rotary supply valve.

  The cylindrical rotary supply valve having the above-described structure is formed into a cylindrical structure in which one end is closed and the other end is open, and a plurality of supply holes are symmetrically formed with respect to the central axis on a part of the cylindrical surface. Combined with a cylindrical rotary outlet valve that is installed and arranged at the combustor outlet so as to be rotationally driven, it is excellent in high-speed opening and closing and is less susceptible to fatigue failure due to vibration and repeated stress due to combustion. A valve for a pulse detonation engine that can obtain a high thrust density even in a supersonic air suction type engine that flies at a high altitude can be obtained by increasing the pressure and density in the process of filling the mixed gas. The cylindrical rotary supply valve and the cylindrical rotary outlet valve can be provided so as to be independently rotatable. However, it is desirable that they be connected to each other by a central axis so as to be integrally rotated. .

  According to the pulse detonation engine valve of claim 1 of the present invention, since the supply valve is a cylindrical rotary type, it is excellent in high-speed opening and closing, and can be disposed on the center side of a plurality of combustors, In addition, since a plurality of supply holes are provided symmetrically with respect to the central axis, combustion can be repeated at the same time on the axis symmetry, and there is an effect of reducing pressure vibration due to combustion, and fatigue fracture resistance Can be improved.

  Further, according to the pulse detonation engine valve of claim 2, in addition to the above-mentioned effect, by providing a cylindrical rotary outlet valve, the combustor is closed at the time of fuel and oxidant filling, The pressure and density in the fuel and oxidant charging process can be increased, and the thrust density of the engine can be improved. Therefore, the air suction type pulse detonation engine can be operated at high altitude / high speed flight, and for example, a pulse detonation engine using a rocket engine can be used in outer space.

  Furthermore, according to the valve for a pulse detonation engine according to claim 3, since the cylindrical rotary supply valve and the cylindrical rotary outlet valve are connected by a central axis and can be driven to rotate integrally, a simple configuration can be used. It becomes possible to operate the supply valve and the outlet valve at high speed at high speed.

Embodiments of the present invention will be described below. FIG. 1A is a schematic perspective view of a valve for a pulse detonation engine according to an embodiment of the present invention, and FIG. 1B is a sectional view thereof.
A valve 1 for a pulse detonation engine according to an embodiment of the present invention has a cylindrical rotary valve structure, and a cylindrical rotary supply valve 2 and a cylindrical rotary outlet valve 3 are connected by a central shaft 4 and are integrally formed. ing. The cylindrical rotary supply valve 2 has an opening 5 at one end and a blocking wall 6 at the other end, and a plurality of supply holes 7 for supplying oxidant and fuel are symmetrically formed on the cylindrical surface with respect to the central axis. (Two in the illustrated embodiment) are formed. On the other hand, the cylindrical rotary outlet valve 3 has a closed wall 8 on the cylindrical rotary supply valve side and an opening 9 on the other end. A plurality (two in the illustrated embodiment) of outlet holes 10 for exhausting combustion gas from the combustor are symmetrically formed with respect to the central axis. The supply hole 7 and the outlet hole 10 are provided out of phase with each other so that when the mixed gas is supplied to the combustor, the outlet side of the combustor is closed.

The pulse detonation engine valve of the present embodiment is configured as described above, and is applied to the pulse detonation engine as shown in FIG. 2, for example. FIG. 2 is a schematic cross-sectional view of a detonation engine to which the above-described pulse detonation engine valve is applied.
The pulse detonation engine 20 of the present embodiment has an intake 11 whose main components are ram-compressed air, an air cooler 12, a precombustor 14, a fuel injector 16, an igniter 18, and a cylindrical rotary supply valve 2. A pulse detonation engine and a ramjet comprising a pulse detonation engine valve 1, a combustor 15 and a nozzle 19 integrally formed by connecting a cylindrical rotary outlet valve 3 with a central shaft 4 and using the pulse detonation in the main combustion process. This is a pulse detonation ramjet engine with integrated engine.

  A number of combustors (combustion tubes) 15 are arranged on the circumference around the valve 1 for the pulse detonation engine so as to be axially symmetric with respect to the axis (in this embodiment, as shown in FIG. 16 pieces of ~ p) are arranged. As shown in FIG. 2, the pulse detonation engine valve 1 is rotationally driven with its central shaft 4 connected via an appropriate actuator 21 such as a motor and a transmission mechanism 22. Note that the central shaft 4 can also be configured to be directly driven by a turbine using the vaporization energy of the fuel. The cylindrical rotary supply valve 2 is configured such that the mixed gas flows into the precombustor 14 and the combustor 15 only when the phases of the supply hole 7 and the combustor hole coincide. Similarly, combustion gas can be exhausted from the combustor only when the outlet hole 10 of the cylindrical rotary outlet valve 3 and the outlet hole of the combustor coincide. Accordingly, the pulse detonation engine valve 1 rotates at the center of the combustor group while the cylindrical rotary supply valve 2 and the cylindrical rotary outlet valve 3 always maintain the same phase relationship, and the supply hole of the cylindrical rotary supply valve 2 is rotated. 7 sequentially matches the upstream openings of the combustors a to p, so that the mixed gas is sequentially supplied to the combustors a to p, and the outlet hole 10 of the cylindrical rotary outlet valve 3 matches the outlet opening of the combustor 15. By doing so, the combustion gas in the combustors a to p is sequentially discharged to the outside.

  In the pulse detonation engine 20 configured as described above, the ram compressed air taken in by the intake 11 is heat-exchanged with a cryogenic refrigerant by an air cooler (heat exchanger) 12, cooled and densified, and rotated in a cylinder. It is supplied to the combustor (combustion pipe) 15 through the type supply valve 2. As the low-temperature medium of the air cooler 12, it is desirable to use liquid hydrogen used as fuel. After the fuel is heated by the air cooler 12, the fuel is supplied to the combustor 15 through the fuel injector 16 and the cylindrical rotary supply valve 2. In the state shown in FIG. 3B, the combustors a, b, i, j facing the supply hole 7 of the cylindrical rotary supply valve 2 are supplied with air and fuel (air and fuel are referred to as mixed gas). In the filling process. At that time, the outlet ends of the combustors a, b, i, j are closed by the cylindrical rotary outlet valve 3 (see FIG. 3D). Therefore, when the mixed gas is filled, the inside of the combustor is shut off from the outside air, the supply pressure of the mixed gas can be made equal to the intake outlet pressure, and the filling pressure can be increased.

When the pulse detonation engine valve rotates 45 ° from this state, the inlets of the combustors a, b, i, j are blocked by the cylindrical rotary supply valve 2 and ignited by the igniter 18 from the closed end of the precombustor 14. Then, it enters the combustion process and combustion by detonation waves is performed. Although combustion immediately after ignition is a defragmentation wave, the precombustor 14 has a smaller diameter than the combustor 15 as shown in the figure, so that it is easy to transition from defragmentation to detonation, and a stable detonation wave propagates to the combustor 15. To do. At that time, the outlet ends of the combustors a, b, i, j are still closed by the cylindrical rotary outlet valve 3 (FIG. 4B). At that time, the combustors c, d, k, and l are in the filling process. Furthermore, while the pulse detonation engine valve rotates 45 °, the detonation wave reaches the outlet end of the combustor, at which time the inlets of the combustors a, b, i, and j are blocked by the cylindrical rotary supply valve. The state is maintained, the outlet hole 10 of the cylindrical rotary outlet valve is in a state where it coincides with the outlets of the combustors a, b, i, j, and combustion waves are ejected to the nozzle 19. Although the detonation wave propagates at an ultra-high speed exceeding 1000 m / s, the outlet valve is a cylindrical rotary type, so that the outlet valve can be opened and closed at a high speed.
At that time, the combustors c, d, k, and l are in the combustion process. Further, the combustion gas is exhausted from the nozzle 19 to the outside while the pulse detonation engine valve rotates 45 °. Thereafter, supply, combustion, and exhaust are repeated at 10 to 100 Hz in the individual combustors in this way. And as a whole engine, in each of the two sets of combustors having phases different from each other by 180 °, the supply, combustion, and exhaust processes are performed simultaneously, and the processes are sequentially repeated in each combustor. A certain thrust can be obtained.

  As described above, according to the pulp detonation engine valve of the present embodiment, the cylindrical rotary supply valve 2 and the cylindrical rotary outlet valve 3 always rotate in the same phase relationship, so the supply of each combustor The ignition and exhaust timing can always be performed in the same phase without deviation. Further, by controlling the ignition timing of the igniter based on the position signal of the drive mechanism, the time lag is also reduced with respect to the ignition timing.

  The surrounding environment of the cylindrical rotary supply valve 2 and the cylindrical rotary outlet valve 3 is a tough structure because there is a risk of strength deterioration and breakage due to metal fatigue and thermal fatigue because high temperature and high pressure periodically act due to detonation. Although necessary, the valve of the present invention always suppresses metal fatigue and thermal fatigue by performing the supply, combustion, and exhaust processes at phases that are 180 degrees different from each other and applying high-pressure air to the outer peripheral side of the valve. That is, the pressure acting by combustion always acts in the direction of the central axis of the cylinder, and always generates the same force in the opposite phase, thereby canceling the force received by the entire valve. As a result, not only high reliability of the cylindrical rotary supply valve and cylindrical rotary outlet valve but also power reduction for driving can be performed, and the drive mechanism can be reduced in size and weight. Also, the life of the bearing mechanism that supports the valve and the shaft can be increased, and the size and weight can be reduced.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various design changes can be made within the scope of the technical idea. For example, in the above-described embodiment, the cylindrical rotary supply valve and the cylindrical rotary outlet valve are integrally connected with the central axis and integrally driven. However, the cylindrical rotary supply valve and the cylindrical rotary outlet valve may be driven separately. Moreover, although it is a case where it applies to a pulse detonation ramjet engine in the said embodiment, it is not necessarily restricted to this, The application to the pulse detonation engine of another type is also possible.

  The valve for a pulse detonation engine according to the present invention is configured as a cylindrical rotary valve, so that it is excellent in high-speed opening and closing performance, metal fatigue / thermal fatigue alleviation, and the drive mechanism is reduced in size, weight and life, and Since the outlet of the combustor can also be opened and closed at high speed and the mixed gas supply pressure to the combustor can be increased, it can be applied to a pulse detonation engine of various applications and types.

It is a perspective view of the valve for pulse detonation engines concerning this embodiment. It is a cross-sectional schematic diagram of the pulse detonation engine to which the valve for pulse detonation engines of FIG. 1 is applied. (A)-(d) is AA sectional drawing in FIG. 2, BB sectional drawing, CC sectional drawing, and DD sectional drawing, respectively. It is a schematic diagram which shows the action | operation of the pulse detonation engine to which this invention is applied. It is a schematic diagram which shows the action | operation of the conventional pulse detonation engine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pulse detonation engine valve 2 Cylindrical rotation type supply valve 3 Cylindrical rotation type outlet valve 4 Center shaft 5, 9 Opening 6, 8 Blocking wall 7 Supply hole 10 Outlet hole 11 Intake 12 Air cooler 14 Precombustor 15 Combustor 16 Fuel injector 18 Igniter 19 Nozzle 20 Pulse detonation engine 21 Actuator

Claims (2)

A valve of a pulse detonation engine that obtains output by detonating a mixed gas of oxidant and fuel with a combustor,
A combustor having a cylindrical structure in which one end on the oxidant intake side is open and the other end is closed, and a plurality of supply holes are provided symmetrically with respect to the central axis in a part of the cylindrical surface. A cylindrical rotary supply valve arranged to be rotatable at the inlet;
It is formed in a cylindrical structure with one end closed and the other end open, and a plurality of outlet holes are provided symmetrically with respect to the central axis on a part of the cylindrical surface and can be driven to rotate at the combustor outlet. Consisting of a combination with a cylindrical rotary outlet valve ,
While the mixed gas is being supplied to the combustor, the cylindrical rotary supply valve is rotated to open the inlet portion of the combustor and the cylindrical rotary outlet valve is closed to close the outlet portion of the combustor. ,and
While the mixed gas is ignited and the combustion wave changes to a detonation wave and propagates to the outlet of the combustor, the cylindrical rotary supply valve closes the inlet of the combustor and the cylindrical rotary outlet valve Rotationally driven to close the outlet of the combustor, and
When the detonation wave reaches the outlet of the combustor, the cylindrical rotary supply valve is rotated to close the inlet of the combustor and the cylindrical rotary outlet valve opens the outlet of the combustor. And
While the combustion gas accompanied by the detonation wave is exhausted to the outside, the cylindrical rotary supply valve rotates so as to close the inlet portion of the combustor and the cylindrical rotary outlet valve opens the outlet portion of the combustor. A valve for a pulse detonation engine that is driven. The valve for a pulse detonation engine according to claim 1 , wherein the cylindrical rotary supply valve and the cylindrical rotary outlet valve are connected by a central axis and are driven to rotate integrally.

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