CN101787939B - Detonation chamber with jetting mechanism - Google Patents

Abstract

The invention relates to a detonation chamber with an injection mechanism, which is characterized in that: the detonation chamber is a double-layer cylinder structure with two inner and outer cylinders forming a cavity, one end is a main propellant injection panel, and the other end is an open mouth structure; the inner cylinder wall of the detonation chamber is provided with equal-pitch semicircular spiral grooves, and the pitch of the spiral groove is equal to the diameter of the detonation chamber; at the bottom of the spiral groove, there is a spray nozzle communicating with the cavity Hole; a spiral is embedded in the spiral groove, the spiral passes through the injection panel, and winds from the injection panel to the open end along the semicircular spiral groove. The invention proposes a detonation chamber with a secondary propellant distributed injection mechanism, which can well solve the problem that the primary and secondary propellants cannot be fully and uniformly mixed when the primary and secondary propellants are coaxially injected.

Description

A detonation chamber with an injection mechanism

technical field

The invention relates to a detonation chamber with an injection mechanism, and relates to the technical field of engines, in particular to a detonation chamber with a secondary propellant distributed injection mechanism applied to a pulse detonation engine.

Background technique

The pulse detonation engine is an unsteady propulsion device that uses the impulse of high-temperature and high-pressure gas generated by periodic detonation waves to generate thrust. When the operating frequency reaches a high frequency, it can be considered to be able to generate stable thrust. The general requirements Can reach more than 100Hz. Therefore, how to improve the working frequency of pulse detonation engine is the direction of many researchers' efforts.

Whether it is a rocket pulse detonation engine or an air-breathing pulse detonation engine, it is basically a two-component propulsion system. For air-breathing pulse detonation engines, air will occupy most of the volume of the combustion chamber, and gas fuel or liquid fuel is relatively small in volume; for rocket-type pulse detonation engines, liquid oxygen/gas hydrogen, oxygen/kerosene, etc. are usually used system. No matter which system is used, there is a situation where one propellant has a relatively large volume, we call it the main propellant, and the other is called the secondary propellant, such as gas fuel or liquid fuel in an air-breathing engine, liquid oxygen Liquid oxygen in /gas hydrogen, kerosene in oxygen/kerosene are all secondary propellants.

A pulse detonation engine with a classic cycle process, one end is open, the other end injects the main propellant and the secondary propellant intermittently, then ignites and detonates, the detonation wave passes out of the detonation chamber, and then fills the isolation gas to enter the next cycle. A pulse detonation engine must be filled with a considerable volume of barrier gas before re-injection of propellant due to the high temperature of the burned gas expanded in the previous cycle. A pulse detonation rocket engine with oxygen as the main propellant and kerosene as the secondary propellant must use an inert gas such as nitrogen as an isolation gas. The storage and injection of the isolation gas requires a separate system, thus reducing the specific impulse of the engine and payload.

A large number of pulse detonation engine model tests at home and abroad have used solenoid valves to realize the intermittent supply of the main propellant and secondary propellant, but there is a contradiction between the frequency and supply capacity of the solenoid valve, and the use of high-frequency and low-flow solenoid valves to realize the propellant In the case of distributed supply, it is also faced with the difficulty of power supply to the solenoid valve and the inability to ensure that the work is completely consistent due to the individual differences of the solenoid valve. Researchers at home and abroad have also developed rotary valves applied to pulse detonation engines. The structure of the rotary valve is complex, and the supply timing of the main propellant and the secondary propellant cannot be flexibly changed.

There are two ways to detonate a pulse detonation engine: direct detonation and indirect detonation. Direct detonation can generate detonation waves at the moment of detonation, but requires high detonation ignition energy. Indirect detonation is a detonation method based on the transition from deflagration to detonation. Usually, a detonation enhancement device is used in the engine to accelerate the transition from deflagration to detonation. The process of detonation transformation, the cooling and service life of the detonation enhancement device have become a concern of researchers.

For an air-breathing pulse detonation engine with air as the main propellant and gasoline as the secondary propellant, both the primary and secondary propellants are supplied adaptively without valves, but the injection pressures of the primary and secondary propellants are different. When the pressure in the combustion chamber When lowering, a single propellant is always injected first rather than a combustible mixture of primary and secondary propellants, so no additional barrier gas is required. The existing problems are: when the primary and secondary propellants are coaxially injected, the primary and secondary propellants cannot be fully and uniformly mixed; Fuller, but slower filling.

At present, the Shchelkin spiral is the most commonly used detonation enhancement device in pulse detonation engines. Since the Shchelkin spiral cannot be cooled, the Shchelkin spiral fails due to ablation deformation after a period of use.

Contents of the invention

technical problem to be solved

In order to avoid the deficiencies of the prior art, the present invention proposes a detonation chamber with an injection mechanism, which is a detonation enhancement device of a pulse detonation engine, and at the same time, the secondary propellant can carry out the injection mechanism Cooling can increase the operating frequency of the pulse detonation engine.

Technical solutions

A detonation chamber with an injection mechanism is characterized in that it includes a detonation chamber and a spiral; the detonation chamber is a double-layer cylindrical structure in which two inner and outer cylinders form a cavity, one end is the main propellant injection panel, and the other One end is an open structure; the inner cylinder wall 8 of the detonation chamber is provided with a semicircular spiral groove 3 of equal pitch, and the pitch of the spiral groove 3 is equal to the diameter of the detonation chamber; at the bottom of the spiral groove, there is a Injection hole 4 with the same chamber; insert spiral 5 in spiral groove 3, spiral 5 passes through the injection panel, and winds from the injection panel to the open end along the semicircular spiral groove; the spiral 5 is provided with There are several secondary injection holes 6; the diameter of the injection hole 4 or the secondary injection hole 6 is less than 0.5mm, and the distance between the centers of the two holes is greater than twice the diameter of the hole; the injection hole 4 and the secondary injection hole 6 The quantity is equal.

In the spiral 5, a distributed injection mechanism is inserted along the axial center; the distributed injection mechanism includes the injection rod 10 of the distributed injection mechanism, the spiral groove 11 of the distributed injection mechanism, the distributed injection mechanism The injection hole 12 of the injection mechanism, the screw 13 of the distributed injection mechanism and the secondary injection hole 14 of the distributed injection mechanism; the inside of the injection rod 10 of the distributed injection mechanism is a through-hole structure forming a cavity, The outer surface of the injection rod is provided with a helical groove 11 of a semicircular distributed injection mechanism with equal pitch, and along the bottom of the helical groove, an injection hole 12 of a distributed injection mechanism communicated with the cavity is provided; The outer ring of the injection rod 10 of the type injection mechanism is embedded in the spiral groove and wound with the spiral 13 of the distributed injection mechanism, and the spiral 13 of the distributed injection mechanism is provided with several secondary injection Hole 14; the distributed injection mechanism extends along the central axis of the detonation chamber to the outlet of the detonation chamber, and the length is equal to the length of the detonation chamber of the pulse detonation engine. The ratio of the inner diameter is not more than 2/3; the diameter of the injection hole 12 of the distributed injection mechanism or the secondary injection hole 14 of the distributed injection mechanism is less than 0.5mm, and the center distance between the two holes is greater than twice the aperture; The injection holes 12 of the distributed injection mechanism are equal in number to the secondary injection holes 14 of the distributed injection mechanism.

The spiral 5 is a circular winding wire, which is wound from the end of the injection panel in such a way that half of the winding wire protrudes from the spiral groove 3, and the length is 6-8 times the pitch of the spiral 5; the remaining part of the winding wire is semicircular, and It is flush with the outer edge of the semicircular spiral groove 3.

The spiral 13 of the distributed injection mechanism is a circular winding wire, and the fixed end of the injection rod 10 of the distributed injection mechanism is wound in such a way that half of the winding wire protrudes from the spiral groove 11 of the distributed injection mechanism, and the length It is 6-8 times the pitch of the helix 13 of the distributed injection mechanism; the remaining part of the winding wire is semicircular, and is flush with the outer edge of the helical groove 11 of the semicircular distributed injection mechanism.

Beneficial effect

The invention proposes a detonation chamber with an injection mechanism, which can well solve the problem that the primary and secondary propellants cannot be fully and uniformly mixed when the primary and secondary propellants are coaxially injected. The main propellant is injected axially from the main propellant injection panel. When the interface between the main propellant and high-temperature exhaust gas propagates to the outlet of the combustion chamber of the pulse detonation engine, the screw drive mechanism drives the screw 5 to move forward along the screw groove 3, so that the screw All the secondary propellant injection holes 4 in the slot coincide completely with all the secondary propellant secondary injection holes 6 on the spiral, and the secondary propellant is injected into the combustion chamber filled with the main propellant, thereby instantly forming a two-component detonable mixture gas. According to the equivalent ratio of the primary and secondary propellants and the atomization quality requirements, the appropriate secondary propellant cavity pressure, injection hole diameter and distribution density can be selected to ensure that the hole center distance is greater than twice the hole diameter. After the secondary propellant injection is completed, the screw drive mechanism drives the screw 5 to move backward along the spiral groove 3, so that the secondary propellant injection holes 4 in the spiral groove and the secondary propellant secondary injection holes 6 on the screw are staggered again. Since the axial filling speed of the main propellant can be very fast, and the distributed injection of the secondary propellant can fully mix the primary and secondary propellants, so the working frequency of the pulse detonation engine can be increased.

In the present invention, the helix 5 protrudes from the helical groove 3 at the end close to the main propellant injection panel of the pulse detonation engine, as a detonation enhancement device. After the transition from deflagration to detonation is completed, the helix 5 no longer protrudes in order to reduce the flow loss The spiral groove 3, but just flush with the outer edge of the spiral groove. According to experimental research, the length of the helical part of the protruding helical groove is 6 to 8 times the diameter of the pulse detonation combustion chamber. At the same time, the secondary propellant can cool the injection mechanism, thereby increasing the service life of the injection mechanism. It solves the problem that the Shchelkin spiral fails due to ablation deformation after a period of use due to the inability to cool the Shchelkin spiral.

Description of drawings

Fig. 1: structural diagram of the present invention and the structural diagram of embodiment 1

Figure 2: Structural diagram of Embodiment 2 of the present invention

Fig. 3: the structural diagram of injection rod 10 in the distributed injection mechanism of the present invention

Fig. 4: the structural diagram of screw 13 in the distributed injection mechanism of the present invention

1. Secondary propellant chamber, 2. Secondary propellant supply joint, 3. Spiral groove, 4. Secondary propellant injection hole in the spiral groove connected to the chamber, 5. Spiral, 6. Secondary propellant on the spiral Secondary injection hole, 7. Detonation outer cylinder wall, 8. Detonation inner cylinder wall, 9. Secondary propellant chamber in distributed injection mechanism, 10. Injection rod in distributed injection mechanism, 11 .The spiral groove in the distributed injection mechanism, 12. The secondary propellant injection hole in the distributed injection mechanism, 13. The spiral in the distributed injection mechanism, 14. The secondary propellant in the distributed injection mechanism secondary injection hole

Detailed ways

Now in conjunction with embodiment, accompanying drawing, the present invention will be further described:

Embodiment 1 As shown in Figure 1: the detonation chamber is a double-layer cylindrical structure with two inner and outer cylinders forming a cavity, one end is the main propellant injection panel, and the other end is an open structure; the length of the detonation chamber is 1300mm with a diameter of 60mm. Two cylinders inside and outside the detonation chamber form an annular cavity, the distance between the two sides of the annular cavity is 10mm, and the inner cylinder wall surface 8 of the detonation chamber is provided with 21 semicircular spiral grooves 3 with equal pitch. The radius of the groove 3 is 4mm, and the pitch of the spiral groove 3 is equal to the diameter of the detonation chamber. Along the bottom of the spiral groove, there is an injection hole 4 communicating with the cavity. The diameter of the injection hole 4 is 0.4mm. The spacing is greater than twice the hole diameter; the spiral 5 is embedded in the spiral groove 3, the spiral 5 passes through the injection panel, and is wound from the injection panel to the open end along the semicircular spiral groove; there are several secondary injection nozzles on the spiral 5 Injection hole 6, the diameter of secondary injection hole 6 is 0.4mm, and the distance between the centers of the two holes is greater than twice the aperture; the number of said injection holes 4 and secondary injection holes 6 is equal. The spiral 5 is a circular winding wire, which is wound in such a way that half of the winding wire protrudes from the helical groove 3 from the end of the injection panel, and the length is 8 times the pitch of the spiral 5; the rest of the winding wires are semicircular, and The outer edge of the semicircular spiral groove 3 is flush.

The left end of the detonation chamber of the pulse detonation engine is the main propellant injection panel, and the right end is the outlet of the detonation chamber. When the pressure in the detonation chamber is lower than the injection pressure of the main propellant, the main propellant is injected axially from the main panel of the main propellant injection. The secondary propellant chamber 1 communicates with the secondary propellant supply system through the secondary propellant joint 2 . When the interface between the main propellant and the high-temperature exhaust gas propagates to the outlet of the detonation chamber of the pulse detonation engine, the screw driving mechanism drives the screw 5 to move forward along the screw groove 3, so that all the secondary propellant injection holes in the screw groove and all the secondary propellant injection holes on the screw The secondary propellant injection holes of the secondary propellant are completely overlapped, and the secondary propellant is injected into the detonation chamber filled with the primary propellant, thereby instantly forming a two-component detonable gas mixture. After the secondary propellant injection is completed, the screw driving mechanism drives the screw 5 to move backward along the spiral groove 3, so that the secondary propellant injection holes in the spiral groove and the secondary propellant injection holes on the screw are staggered again. At this time, ignition is carried out at one end close to the main propellant injection panel of the pulse detonation engine, and the spiral 5 protruding from the spiral groove 3 accelerates the combustion transition from deflagration to detonation. After the transformation is completed, in order to reduce the flow loss, the spiral 5 no longer protrudes from the spiral groove 3, but just flush with the outer edge of the spiral groove. According to experimental research, the length of the helical part of the protruding helical groove is 6 to 8 times the diameter of the detonation chamber of the pulse detonation engine. At the same time, the secondary propellant can cool the injection mechanism, thereby increasing the service life of the injection mechanism.

Embodiment 2 is shown in Figure 2: the detonation chamber is a double-layer cylindrical structure with two inner and outer cylinders forming a cavity, one end is the main propellant injection panel, and the other end is an open structure; the length of the detonation chamber is 750mm with a diameter of 60mm. The two cylinders inside and outside the detonation chamber form an annular cavity, and the distance between the two sides of the annular cavity is 10mm. There are 12 semicircular spiral grooves 3 with equal pitches on the wall surface 8 of the inner cylinder of the detonation chamber. The radius of the groove 3 is 4mm, and the pitch of the spiral groove 3 is equal to the diameter of the detonation chamber. Along the bottom of the spiral groove, there is an injection hole 4 communicating with the cavity. The diameter of the injection hole 4 is 0.4mm. The spacing is greater than twice the hole diameter; the spiral 5 is embedded in the spiral groove 3, the spiral 5 passes through the injection panel, and is wound from the injection panel to the open end along the semicircular spiral groove; there are several secondary injection nozzles on the spiral 5 Injection hole 6, the diameter of secondary injection hole 6 is 0.4mm, and the distance between the centers of the two holes is greater than twice the aperture; the number of said injection holes 4 and secondary injection holes 6 is equal. The spiral 5 is a circular winding wire, which is wound in such a way that half of the winding wire protrudes from the spiral groove 3 from the end of the injection panel, and the length is 6 times the pitch of the spiral 5; The outer edge of the circular spiral groove 3 is flush.

In the center of the injection panel, a distributed injection mechanism is inserted along the axial center. One end of the injection rod 10 of the distributed injection mechanism passes through and is fixed in the center of the injection panel, and the spiral 13 of the distributed injection mechanism passes through the injection panel; the distributed injection mechanism extends along the central axis of the detonation chamber To the outlet of the detonation chamber, the length is 750mm; the distributed injection mechanism includes an injection rod 10, a spiral groove 11, an injection hole 12, a spiral 13 and a secondary injection hole 14; the inside of the injection rod 10 is a cavity forming Through-hole structure, the diameter of the inner hole is 10 mm, and the ratio of the outer diameter of the injection rod 10 to the inner diameter of the detonation is 1/3; the outer surface of the injection rod is provided with 26 equal-pitch semicircular spiral grooves 11, The radius of the spiral groove 3 is 4 mm, and the pitch of the spiral groove 11 is 60 mm. Along the bottom of the spiral groove, an injection hole 12 communicating with the cavity is provided, and the diameter of the injection hole 12 is 0.4 mm; The outer ring is embedded in the spiral groove and wound with a circular wire-wound helix 13. The helix 13 is provided with several secondary injection holes 14, and the diameter of the secondary injection holes 14 is 0.4 mm; the spiral 13 is self-injection panel end Winding in such a way that half of the winding wire protrudes from the spiral groove 11, the length is 6 times the pitch of the spiral 13; the rest of the winding wire is semicircular and flush with the outer edge of the semicircular spiral groove 11; the injection hole 12 Or the distance between the centers of the secondary injection holes 14 is greater than twice the hole diameter; the number of the injection holes 12 and the secondary injection holes 14 is equal.

The left end of the detonation chamber of the pulse detonation engine is the main propellant injection panel, and the right end is the outlet of the detonation chamber. When the pressure in the detonation chamber is lower than the injection pressure of the main propellant, the main propellant is injected axially from the main panel of the main propellant injection. The secondary propellant chamber 1 communicates with the secondary propellant supply system through the secondary propellant joint 2, and the distributed injection mechanism directly communicates with the secondary propellant system. When the interface between the main propellant and high-temperature exhaust gas propagates to the outlet of the detonation chamber of the pulse detonation engine, the screw drive mechanism drives the screw 5 to move forward along the screw groove 3, so that all the secondary propellant injection holes in the screw groove 3 are connected to the screw 5 All the secondary propellant injection holes above are completely overlapped, and the screw 13 on the distributed injection mechanism also moves forward along the spiral groove 11 under the drive of the screw drive mechanism, so that all the secondary propellant injection holes in the spiral groove 11 The injection hole completely coincides with all the secondary propellant injection holes on the spiral 13, and the secondary propellant is sprayed into the detonation chamber filled with the primary propellant, thereby instantly forming a two-component detonable gas mixture. After the secondary propellant injection is completed, the screw drive mechanism drives the screw 5 to move backward along the spiral groove 3, so that the secondary propellant injection holes in the spiral groove 3 and the secondary propellant injection holes on the screw 5 are staggered again, and simultaneously drive The spiral 13 also moves backward along the spiral groove 11, so that the secondary propellant injection holes in the spiral groove 11 and the secondary propellant injection holes on the spiral 13 are also staggered. At this time, ignition is carried out at one end close to the main propellant injection panel of the pulse detonation engine, and the spiral 5 protruding from the spiral groove 3 and the spiral 13 protruding from the spiral groove 11 accelerate the combustion transition from deflagration to detonation. After the transformation is completed, in order to reduce the flow loss , the helix 5 and the helix 13 no longer protrude from their respective helical grooves, but are just flush with the outer edge of the helical grooves. According to experimental research, the length of the helical part of the protruding helical groove is 6 to 8 times the diameter of the detonation chamber of the pulse detonation engine. At the same time, the secondary propellant can cool the injection mechanism, thereby increasing the service life of the injection mechanism.

Claims (4)

1. A detonation chamber with an injection mechanism is characterized in that it comprises a detonation chamber and a spiral; the detonation chamber is a double-deck cylindrical structure formed by two inner and outer cylinders, and one end is the main propellant injection panel , the other end is an open structure; the inner cylinder wall (8) of the detonation chamber is provided with a semicircular spiral groove (3) of equal pitch, and the pitch of the spiral groove (3) is equal to the diameter of the detonation chamber; At the bottom of the spiral groove, there is an injection hole (4) communicating with the cavity; a spiral (5) is embedded in the spiral groove (3), and the spiral (5) passes through the injection panel, along the semicircular spiral groove. The injection panel is wound to the open end; the spiral (5) is provided with several secondary injection holes (6); the diameter of the injection hole (4) or the secondary injection hole (6) is less than 0.5mm , the distance between the centers of the two holes is greater than twice the diameter of the hole; the number of the injection holes (4) and the secondary injection holes (6) is equal. 2. The detonation chamber with an injection mechanism according to claim 1, characterized in that: in the spiral (5), a distributed injection mechanism is inserted along the axial center; the distributed injection mechanism includes The injection rod (10) of the distributed injection mechanism, the spiral groove (11) of the distributed injection mechanism, the injection hole (12) of the distributed injection mechanism, the spiral (13) and distribution of the distributed injection mechanism The secondary injection hole (14) of the type injection mechanism; the inside of the injection rod (10) of the distributed injection mechanism is a through-hole structure forming a cavity, and the outer surface of the injection rod is provided with a semicircle with equal pitch. The spiral groove (11) of the distributed injection mechanism, along the bottom of the spiral groove, is provided with the injection hole (12) of the distributed injection mechanism communicated with the cavity; the injection rod (10) of the distributed injection mechanism ), the spiral (13) of the distributed injection mechanism is embedded in the spiral groove, and the spiral (13) of the distributed injection mechanism is provided with several secondary injection holes (14) of the distributed injection mechanism The distributed injection mechanism extends to the detonation chamber outlet along the central axis of the detonation chamber, and the length is equal to the length of the pulse detonation engine detonation chamber, and the outer diameter of the injection rod (10) of the distributed injection mechanism is the same as The ratio of the inner diameter is not more than 2/3; the diameter of the injection hole (12) of the distributed injection mechanism or the secondary injection hole (14) of the distributed injection mechanism is less than 0.5mm, and the distance between the centers of the two holes is greater than that of the aperture. twice; the number of injection holes (12) of the distributed injection mechanism is equal to the number of secondary injection holes (14) of the distributed injection mechanism. the 3. The detonation chamber with an injection mechanism according to claim 1, characterized in that: a part of the winding wire of the spiral (5) is a circular winding wire, protruding from the end of the injection panel with half of the winding wire The spiral groove (3) is wound, and the length is 6-8 times the pitch of the spiral (5); the remaining part of the winding wire is semicircular, and is flush with the outer edge of the semicircular spiral groove (3). 4. The detonation chamber with an injection mechanism according to claim 2, characterized in that: a part of the spiral (13) winding wire of the distributed injection mechanism is a circular winding wire, and the self-distributed injection The fixed end of the injection rod (10) of the mechanism is wound in such a way that half of the winding wire protrudes from the spiral groove (11) of the distributed injection mechanism, and the length is 6-8 times the pitch of the spiral (13) of the distributed injection mechanism; Part of the winding wire is semicircular and flush with the outer edge of the helical groove (11) of the semicircular distributed injection mechanism. the

Images