CN103089445A - Counter pressure preventing structure of air inlet channel of inspiration type impulse knocking engine - Google Patents

Abstract

The present invention proposes an air-breathing pulse detonation engine inlet port anti-backpressure structure, including an intake cone, a cylindrical pipe section, a pressure stabilizing chamber and an actuating mechanism; there are two rows of annular layouts on the side wall of the cylindrical pipe section The drainage hole; the pressure stabilizing chamber is a thin-walled stepped cylindrical structure with a large diameter in the middle and small diameters at both ends, and an annular pressure relief groove is opened on the wall of the middle section of the stabilizing chamber; the actuating mechanism is installed inside the middle section of the stabilizing chamber, and acts The moving mechanism can be axially sealed and slid; the pressure stabilizing chamber is sleeved on the outer wall of the cylindrical pipe section, and the two ends of the pressure stabilizing chamber are coaxially sealed and fixedly connected with the cylindrical pipe section; the two rows of drainage holes on the side wall of the cylindrical pipe section respectively correspond to the pressure stabilizing chamber Small diameter segments at both ends. The present invention cooperates with the pressure stabilizing chamber and the actuating mechanism to realize the isolation of the high total pressure incoming flow from the outside air during intake; after the detonation is formed, the reverse flow acts on the actuating mechanism, and the stabilizing chamber communicates the reverse flow with the outside world. And the reverse flow enters the diversion chamber and then discharges in reverse to achieve the purpose of reducing the back pressure of the intake duct.

Description

An air-breathing pulse detonation engine intake port anti-backpressure structure

technical field

The invention relates to the technical field of engines, in particular to an air-breathing pulse detonation engine inlet port anti-backpressure structure.

Background technique

A pulse detonation engine is a power device that works periodically. Pulse detonation engines can be divided into air-breathing pulse detonation engines and rocket-type pulse detonation engines according to whether they have their own oxidant. As the air-breathing pulse detonation engine needs to periodically inhale air as the oxidant, its air inlet cannot be completely closed.

The detonation wave formed during the working process of the air-breathing pulse detonation engine will propagate to both sides of the detonation chamber, and the detonation wave propagating to the air inlet is called the return detonation wave. The back-propagating detonation wave will attenuate into a shock wave and propagate to the intake port under the action of the detonation chamber obstacle, and the gas after the shock wave will also flow into the intake port. The anti-propagation shock wave and gas not only degrade the propulsion performance of the engine, but also affect the normal operation of the engine. Therefore, a mechanical valve or a pneumatic valve must be installed between the air inlet and the detonation chamber. Although existing mechanical valves such as rotary valves can isolate the reverse flow from the intake passage, the high total pressure incoming flow stagnates on the valve body resulting in a large negative thrust, and there are rotating parts and control systems on the rotary valve. Increased system complexity. The requirement of the pneumatic valve is that the forward flow resistance is small and the reverse flow resistance is large, so as to effectively reduce the reverse flow pressure and reduce the pressure pulsation of the intake passage. Existing pneumatic valves such as Srnirnov's cone-shaped pneumatic valve have great forward air intake resistance, while the structure of the swirler-type pneumatic valve is complex, and the blades are easily deformed after being subjected to periodic pulse pressure. In conclusion, the use of pneumatic valves to reduce intake back pressure still needs a lot of research work.

Contents of the invention

technical problem to be solved

In order to solve the problems existing in the prior art, the present invention proposes an air-breathing pulse detonation engine intake port anti-backpressure structure, which can enhance the positive thrust of the pulse detonation engine and reduce the back pressure of the intake port , while improving airflow and fuel blending.

Technical solutions

Technical scheme of the present invention is:

The air-breathing pulse detonation engine intake port anti-backpressure structure is characterized in that it includes an intake cone, a cylindrical pipe section, a pressure stabilizing chamber and an actuating mechanism; two rows are arranged on the side wall of the cylindrical pipe section Drain holes in a circular layout; the air intake cone is coaxially installed in the center of the cylindrical pipe section, and is fixedly connected to the cylindrical pipe section through the fuel channel on the air intake cone, and an annular channel is formed between the air intake cone and the cylindrical pipe section; the stable The pressure chamber is a thin-walled stepped cylindrical structure with a large diameter in the middle and small diameters at both ends. The diameter of the central through hole on both ends of the pressure stabilization chamber is equal to the outer diameter of the side wall of the cylindrical pipe section. There is an annular pressure relief groove on the wall of the middle section of the pressure stabilization chamber. ; The actuating mechanism is made up of two annular plates, the outer diameter of the annular plate is equal to the inner diameter of the middle section of the pressure stabilizing chamber, the inner diameter of the annular plate is equal to the outer diameter of the side wall surface of the cylindrical pipe section, and the space between the two annular plates is It is fixedly connected by multiple axial struts; the axial distance between the two annular plates is less than the maximum distance between the annular pressure relief groove and the two ends of the middle wall of the pressure stabilizing chamber, and the distance between the two annular plates The axial distance is greater than the minimum value of the distance between the annular pressure relief groove and the two ends of the wall in the middle section of the pressure stabilizing chamber; the actuating mechanism is installed inside the middle section of the stabilizing chamber, and the actuating mechanism can be axially sealed and slid; the stabilizing chamber is sleeved on a cylindrical pipe section The outer wall, the two ends of the plenum chamber are coaxially sealed and fixedly connected with the cylindrical pipe section; the two rows of drainage holes on the side wall of the cylindrical pipe section respectively correspond to the small diameter sections at both ends of the plenum chamber.

The air-breathing pulse detonation engine intake port anti-backpressure structure is characterized in that: it also includes a diversion cavity, the diversion cavity is a thin-walled cylindrical structure, and the diameter of the central through hole on one end surface of the diversion cavity is equal to The outer diameter of the middle section of the pressure stabilizing chamber; the end face of the diversion chamber and the middle section of the stabilizing chamber are coaxially sealed and fixed, and the annular pressure relief groove is located in the diversion chamber.

The air-breathing pulse detonation engine intake port anti-backpressure structure is characterized in that: it also includes a shock wave reflection device, the center of the shock wave reflection device is a ring structure, and the inner diameter of the ring structure is equal to the intake cone cylinder The outer diameter of the section; the ring structure has several shock wave reflection ends, and the end of each shock wave reflection end is a parabolic surface; the shock wave reflection device is coaxially fixed on the intake cone, and the shock wave reflection end is between the intake cone and the An annular channel is formed between the cylindrical pipe sections, and the parabolic surface at the end of the shock wave reflection end faces the reverse flow and incoming flow direction.

The air-breathing pulse detonation engine intake port anti-backpressure structure is characterized in that: the tail end of the intake cone is a parabolic shock wave focusing and reflecting concave cavity.

The anti-backpressure structure of the air-breathing pulse detonation engine inlet port is characterized in that: a row of oblique jet holes in an annular layout is opened on the wall surface of the shock wave focusing reflection concave cavity at the tail end of the intake cone, and the oblique jet holes Drain holes towards the rear row of cylindrical pipe sections.

Beneficial effect

The present invention cooperates with the pressure stabilizing chamber and the actuating mechanism to realize the isolation of the incoming flow with high total pressure from the outside air during intake air, so that the incoming flow with high total pressure will not flow into the atmosphere; With the function of the actuating mechanism, the pressure stabilizing chamber connects the backflow with the outside world, and the backflow enters the diversion chamber and then is discharged in the reverse direction, so as to reduce the back pressure of the intake port and increase the positive thrust of the engine at the same time. In addition, the present invention also adopts a shock wave reflection device and a shock wave focusing concave cavity to reduce the total pressure of the backflow by reflecting the shock wave.

Description of drawings

Fig. 1. Structural diagram of the present invention

Fig. 2. Diagram of the shock wave reflection device of the present invention

Fig. 3. Cylindrical pipe section structural diagram of the present invention

Figure 4. Structural diagram of the pressure stabilizing chamber and the actuating mechanism of the present invention

Figure 5. A structural diagram of a preferred solution of the present invention

Figure 6. A partial enlarged view of the oblique jet hole of a preferred scheme

Figure 7. Schematic diagram of an embodiment of the present invention

In the figure 1. Intake cone, 2. Shock wave reflection device, 3. Cylindrical pipe section, 4. Pressure stabilizing chamber, 5. Front limit plane, 6. Actuating mechanism, 7. Pressure relief groove, 8. Flow diversion Cavity, 9. rear limit plane, 10. front drainage hole, 11. fuel channel, 12 rear drainage hole, 13. shock wave focusing concave cavity, 14. oblique jet hole, 15. igniter, 16. spiral obstacle , 17. Detonation chamber.

Detailed ways

Describe the present invention below in conjunction with specific embodiment:

This embodiment is used for the head structure of the intake port of an air-breathing pulse detonation engine. Referring to the accompanying drawing 1, the air-breathing pulse detonation engine intake port anti-backpressure structure in this embodiment includes an intake cone 1, a cylindrical pipe section 3, a plenum chamber 4 and an actuating mechanism 6.

Referring to accompanying drawing 2, both ends of the cylindrical pipe section are connecting flanges, and there are two rows of drainage holes in a circular layout on the side wall of the main structure of the cylindrical pipe section, which are the front drainage holes 10 and the rear drainage holes 12 respectively. Referring to accompanying drawing 1, air intake cone is coaxially installed in the center of cylindrical pipe section, and air intake cone is fixedly connected with cylindrical pipe section through fuel channel 11, and an annular channel is formed between air intake cone and cylindrical pipe section.

Referring to Figure 4, the plenum chamber 4 is a thin-walled stepped cylindrical structure with a large diameter in the middle and small diameters at both ends, and a front limiting plane 5 and a rear limiting plane 9 are formed between the large diameter section in the middle and the small diameter sections at both ends. The diameter of the central through hole on both ends of the pressure stabilizing chamber is equal to the outer diameter of the side wall of the cylindrical pipe section. An annular pressure relief groove 7 is opened on the wall surface of the middle section of the pressure stabilizing chamber.

With reference to accompanying drawing 4, actuating mechanism 6 is made up of two annular plates, and the outer diameter of annular plate is equal to the inner diameter of the middle section of the pressure stabilizing chamber, and the inner diameter of annular plate is equal to the outer diameter of the side wall surface of the cylindrical pipe section, and the two annular plates are The plates are fixedly connected by four uniformly distributed axial struts. The axial distance between the two annular plates is smaller than the maximum distance between the annular pressure relief groove and the two ends of the middle wall of the pressure stabilizing chamber, and the axial distance between the two annular plates is greater than the distance between the annular pressure relief groove and the stabilizing chamber. The minimum value of the distance between the two ends of the wall surface in the middle section of the pressure chamber, that is, in this embodiment, the axial distance between the two annular plates is smaller than the axial distance between the annular pressure relief groove and the front limiting plane 5, and the two annular plates The axial distance between the annular plates is greater than the axial distance between the annular pressure relief groove and the rear limiting plane 9, so as to ensure that when the actuating mechanism slides inside the pressure stabilizing chamber, the airflow can flow according to the design requirements.

The actuating mechanism is installed inside the middle section of the pressure stabilizing chamber, and the actuating mechanism can axially seal and slide in the middle section of the stabilizing chamber under the action of the air flow pressure difference. The plenum chamber is set on the outer wall of the cylindrical pipe section, and the two ends of the plenum chamber are coaxially sealed and fixedly connected with the cylindrical pipe section; and the two rows of drainage holes on the side wall of the cylindrical pipe section correspond to the small diameter sections at both ends of the plenum chamber, namely The front drainage hole 10 is at the front side of the front limiting plane 5 , and the rear drainage hole 12 is at the rear side of the rear limiting plane 9 .

When the air-breathing pulse detonation engine is working, the incoming flow with high total pressure enters the engine from the annular channel formed by the intake cone 1 and the cylindrical pipe section 3, and a part of the incoming flow with high total pressure first passes through the front drainage hole 10 and enters the stabilized pressure Cavity 4, pushing the actuator 6 to move along the direction of the incoming flow to the limit plane 9, thereby isolating the incoming flow with high total pressure from the outside air, so that the incoming flow with high total pressure will not flow into the atmosphere. On the other hand, after most of the incoming flow passes through the annular passage, it is mixed with the fuel oil flowing out from the fuel passage 11 and fills the detonation chamber 17. When the detonation chamber is filled, the igniter 15 starts to ignite and ignites the oil and gas in the detonation chamber. After the mixture and the flame are accelerated by the spiral obstacle 16, a detonation wave and a return detonation wave are formed and transmitted to the engine outlet and the air inlet respectively. The return detonation wave is attenuated into a shock wave under the action of obstacles, and the gas behind the shock wave also flows to the intake port. Part of the reverse flow enters the pressure stabilizing chamber 4 from the rear drainage hole 12, and pushes the operating mechanism against the direction of the incoming flow to the limit plane 5. At this time, the pressure relief groove 7 connects the pressure stabilizing chamber 4 with the outside world, and the reverse flow flows from the pressure relief groove Discharge, to achieve the purpose of reducing the back pressure of the intake port.

As a further optimization scheme, there is a diversion chamber 8 outside the pressure stabilizing chamber. The diversion chamber is a thin-walled cylindrical structure. The middle section of the pressure stabilizing chamber is coaxially sealed and fixed, and the annular pressure relief groove is in the diversion chamber. When the reverse flow is discharged from the pressure relief groove 7, it enters the guide cavity 8, and is discharged along the direction opposite to the intake direction of the guide cavity 8, so as to achieve the purpose of reducing the back pressure of the intake port and enhance the positive thrust of the engine. .

As a further optimization scheme, a shock wave reflection device is installed on the intake cone. Referring to accompanying drawing 2, the center of the shock wave reflection device is a ring structure, and the inner diameter of the ring structure is equal to the outer diameter of the cylinder section of the intake cone; A number of shock wave reflection ends, the end of each shock wave reflection end is a parabolic surface; the shock wave reflection device is coaxially fixed on the intake cone, and the shock wave reflection end is located in an annular channel formed between the intake cone and the cylindrical pipe section , and the parabolic surface at the end of the shock wave reflection end faces the reverse flow and incoming flow direction. Using the shock wave reflection device, when the return shock wave passes through the annular channel, multiple reflected shock waves are formed after the interaction between the exit of the channel and the shock wave reflection device 2, further reducing the total pressure of the return flow, so as to ensure the normal operation of the inlet channel .

As a further optimization scheme, the tail end of the intake cone is a parabolic shock focusing and reflecting cavity, so that the return shock wave will reflect a strong shock wave on the shock focusing cavity 13 at the end of the intake cone, reducing the The total pressure of the backflow gas produces a lot of thrust.

As a further optimization scheme, with reference to accompanying drawings 5 and 6, a row of oblique jet holes 14 in an annular layout is opened on the wall of the shock wave focusing and reflecting concave cavity at the tail end of the inlet cone, and the oblique jet holes face toward the back row of the cylindrical pipe section. drainage hole. During the air intake process, the incoming flow with high total pressure passes through the oblique jet holes to form multiple oblique jets and interacts with the fuel from the fuel passage 11 to enhance the mixing of fuel and air. After the detonation is formed, the backflow will also flow out from the oblique jet hole 14 to form an oblique jet flow, which will give the backflow a radial partial velocity after mixing with the backflow, which is beneficial for more backflow to enter the pressure stabilizing chamber through the drainage hole 12 Inside, and flow into the outside through the pressure relief groove 7, so as to effectively reduce the backflow and backpressure, and generate positive thrust.

Claims (5)

1. an air inlet of air-breathing pulse detonation engine back-pressure preventing structure, is characterized in that: comprise inlet cone, cylindrical pipeline section, pressure stabilizing cavity and actuation mechanism; Have the conduction hole of two row's annular layouts on cylindrical pipeline section side wall surface; Inlet cone is coaxial is arranged on cylindrical pipeline section center, and is fixedly connected with cylindrical pipeline section by the fuel gallery on inlet cone, forms the annular pass between inlet cone and cylindrical pipeline section; Described pressure stabilizing cavity is the thin-walled step round column structure of stage casing major diameter, diameter small in ends, and the central through bore diameter of pressure stabilizing cavity both ends of the surface equals cylindrical pipeline section side wall surface external diameter, has annular gas pressure relief slot on the wall of pressure stabilizing cavity stage casing; Described actuation mechanism is comprised of two ring sheets, and ring sheet external diameter equals pressure stabilizing cavity stage casing internal diameter, and ring sheet internal diameter equals cylindrical pipeline section side wall surface external diameter, is fixedly connected with by many axial struts between two ring sheets; Axial distance between two ring sheets is less than the large value of annular gas pressure relief slot and pressure stabilizing cavity stage casing wall both ends of the surface distance, and the axial distance between two ring sheets is greater than the little value of annular gas pressure relief slot and pressure stabilizing cavity stage casing wall both ends of the surface distance; Actuation mechanism is arranged on intersegmental part in pressure stabilizing cavity, and actuation mechanism can be slided in axial seal; Pressure stabilizing cavity is enclosed within cylindrical pipeline section outer wall, and the pressure stabilizing cavity both ends of the surface are fixedly connected with cylindrical pipeline section co-axial seal; On cylindrical pipeline section side wall surface two row conduction hole is corresponding pressure stabilizing cavity diameter section small in ends respectively.

2. a kind of air inlet of air-breathing pulse detonation engine back-pressure preventing structure according to claim 1, it is characterized in that: also include diversion cavity, diversion cavity is the thin wall cylindrical structure, the central through bore diameter of diversion cavity one end face equals pressure stabilizing cavity stage casing external diameter; Diversion cavity end face and pressure stabilizing cavity stage casing co-axial seal are fixed, and annular gas pressure relief slot is in diversion cavity.

3. a kind of air inlet of air-breathing pulse detonation engine back-pressure preventing structure according to claim 2 is characterized in that: also comprise the shock wave reflection device, described shock wave reflection device center is loop configuration, and the internal diameter of loop configuration equals inlet cone cylindrical section external diameter; Loop configuration is extended with some shock wave reflection ends, and the end of each shock wave reflection end is the parabolic profile; The shock wave reflection device is coaxial to be fixed on inlet cone, and the shock wave reflection end is between inlet cone and cylindrical pipeline section and forms in the annular pass, and the parabolic type of shock wave reflection end end is come flow path direction facing to anti-stream.

4. a kind of air inlet of air-breathing pulse detonation engine back-pressure preventing structure according to claim 3, it is characterized in that: the inlet cone tail end is the shock wave focus reflecting and concave-cavity of parabolic type.

5. a kind of air inlet of air-breathing pulse detonation engine back-pressure preventing structure according to claim 4, it is characterized in that: have the oblique fire discharge orifice of row's annular layout on the shock wave focus reflecting and concave-cavity wall of inlet cone tail end, the conduction hole that the oblique fire discharge orifice is arranged after cylindrical pipeline section.

Images