Shock wave focusing detonation initiation device and control method thereof

Abstract

The application discloses a shock wave focusing detonation initiation device and a control method thereof, and belongs to the technical field of detonation combustion initiation. The first air inlet on the air inlet rotating disc is periodically connected and cut off with the second air inlet on the shock wave focusing cavity by rotating the air inlet rotating disc. When connected, under the action of the internal and external gas pressure difference, the external gas enters the shock wave focusing cavity through each set of connected first air inlets and second air inlets, and a stable and reliable unsteady shock wave is generated in the shock wave focusing cavity. The generated multiple unsteady shock waves propagate to the downstream detonation combustion chamber according to a certain trajectory under the constraint of the horn-shaped shell, and are focused at the air outlet of the shock wave focusing cavity, thereby avoiding the pressure reversal phenomenon at the first air inlet, effectively overcoming the shock wave diffraction loss, reducing the shock wave focusing energy loss, and improving the reliability and working condition adaptability of the pulse detonation engine ignition initiation.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of detonation combustion initiation, and more particularly relates to a shock wave focusing detonation initiation device and a control method thereof. BACKGROUND

[0002] Detonation combustion is a combustion mode based on the principle of constant volume combustion, which has a faster combustion speed and reaction heat release rate than the conventional constant pressure combustion principle mode. Therefore, under the same air-fuel ratio condition, it will produce higher combustion overpressure and flame temperature in the combustion chamber, thereby improving the work efficiency of the heat engine. Due to its outstanding theoretical advantages, detonation combustion technology has become one of the most potential supercharged combustion approaches in the future, and has attracted more and more organizations and institutions at home and abroad to pay attention in the development of many new types of revolutionary power propulsion devices.

[0003] Compared with conventional constant pressure combustion, detonation combustion is a non-steady combustion process, and the detonation wave produced thereby brings strong supercharging effect to realize supercharged combustion. Therefore, stable and reliable generation of detonation wave in the detonation combustion chamber is crucial to the detonation combustion technology. At present, the generation of detonation wave mainly includes indirect initiation by deflagration to detonation transition (DDT process) and direct ignition initiation. Although direct ignition initiation has many advantages, it also has disadvantages such as large required ignition energy and difficulty in periodic stable and reliable ignition. Therefore, the prior art mainly adopts indirect initiation, such as the patent (CN116122967A, CN115234403A, CN107131803A, CN104500272A, etc.) proposes a shock wave focusing initiation device, which uses the deflagration wave generated in the pre-explosion tube to focus and initiate the combustible mixture in the tail end cavity of the combustion chamber, which has certain beneficial effects. For example, the patent (CN114962065A) and the patent (CN112196701A) use continuous hot jet or multi-zone ignition to make the hot jet in the pre-chamber focus in the cavity to generate a local high-temperature and high-pressure hot spot area to initiate the combustible mixture in the combustion chamber. Therefore, the local hot spot area generated by shock wave focusing can meet the ignition energy requirement of direct initiation of detonation combustion. However, the above measures all have a certain shock wave diffraction phenomenon, resulting in a certain loss of shock wave focusing energy. SUMMARY

[0004] In view of the above defects or improvement needs of the prior art, the present application provides a shock wave focusing detonation initiation device and a control method thereof, which solve the technical problem that there is a certain loss of shock wave focusing energy due to the shock wave diffraction phenomenon in the prior art.

[0005] In order to achieve the above purpose, the present application provides a shock wave focusing detonation initiation device, comprising: an air inlet rotating disc, a shock wave focusing cavity and a detonation combustion chamber arranged in sequence.

[0006] The intake rotating disc is a three-dimensional circular ring structure, and N first intake ports are arranged on the side circumference of the intake rotating disc; N≥2;

[0007] The shock wave focusing cavity comprises an intake disc and a horn-shaped shell; the intake disc is a three-dimensional circular ring structure, coaxially arranged with the intake rotating disc and sleeved inside the intake rotating disc; N second intake ports are arranged on the side circumference of the intake disc;

[0008] The end surface area of the intake disc is the same as the end surface area of the larger end of the horn-shaped shell; the end surface of the intake disc close to the intake rotating disc is closed, and the end surface away from the intake rotating disc is open and in communication with the larger end of the horn-shaped shell; the smaller end of the horn-shaped shell is provided with an air outlet, which is coaxially connected with the air inlet of the detonation combustion chamber;

[0009] The intake rotating disc rotates under external driving and moves relatively with the stationary shock wave focusing cavity, so that the N first intake ports and the N second intake ports are periodically connected and disconnected, the ignition point for detonation initiation is generated when connected to initiate the combustible mixture in the detonation combustion chamber, and the exhaust of combustion products and the filling of the next period combustible mixture are performed when disconnected.

[0010] Further preferably, the shock wave focusing cavity further comprises N side bending channels; one end of each of the N side bending channels is connected with one of the N second intake ports, and the other end of each of the N side bending channels is connected with the air outlet; wherein the bending direction of each of the N side bending channels is towards the detonation combustion chamber.

[0011] Further preferably, the axial width of any first intake port is the same as the axial width of any second intake port; the circumferential width of any first intake port is greater than or equal to the circumferential width of any second intake port.

[0012] Further preferably, the N first intake ports are uniformly distributed on the side circumference of the intake rotating disc; the N second intake ports are uniformly distributed on the side circumference of the intake disc; the central angle corresponding to any two adjacent first intake ports is the same as the central angle corresponding to any two adjacent second intake ports.

[0013] Further preferably, the N first intake ports are the same in size; the circumferential width of the first intake port The circumferential spacing between any two adjacent first intake ports satisfies:

[0014]

[0015] wherein, is the inner ring radius of the intake disc; is the radius of the air outlet of the horn-shaped shell; is the adiabatic index; is the gas constant; is the rotating speed of the intake rotating disc, unit: rpm; T 1 and T 2 are the gas temperatures in the shock focusing cavity before and after the unsteady shock sweeps through the shock focusing cavity when the N first intake ports and the N second intake ports are communicated, respectively.

[0016] Further preferably, the circumferential width of the first intake port corresponds to a central angle of 2° to 20°; and the circumferential width of the second intake port corresponds to a central angle of 2° to 20°.

[0017] Further preferably, the shape of the detonation combustion chamber is an extended nozzle shape.

[0018] Further preferably, the intake rotating disc and the intake disc are assembled through a gap fit.

[0019] In a second aspect, the present application provides a control method of the above shock focusing detonation initiation device, comprising:

[0020] The intake rotating disc is driven to rotate, so as to relatively move with the stationary shock focusing cavity, and thus the N first intake ports and the N second intake ports are periodically communicated and disconnected;

[0021] When the N first intake ports and the N second intake ports are communicated, the external gas enters the shock focusing cavity through each set of communicated first intake port and second intake port under the action of pressure difference to generate unsteady shock; the N unsteady shocks are focused at the gas outlet of the shock focusing cavity to generate an ignition point of detonation initiation to initiate the combustible mixture in the detonation combustion chamber;

[0022] When the N first intake ports and the N second intake ports are disconnected, the exhaust of combustion products and the filling of the next period of combustible mixture are performed.

[0023] Further preferably, the rotating speed of the intake rotating disc is controlled, so as to control the generation frequency of the unsteady shock, and further control the frequency of the ignition point of detonation initiation generated at the gas outlet of the shock focusing cavity.

[0024] Overall, the above technical solutions conceived by the present application can achieve the following beneficial effects:

[0025] 1. The shock wave focusing detonation initiation device provided by the present application comprises a rotating air inlet disc, a plurality of first air inlets on the rotating air inlet disc, a plurality of second air inlets on a shock wave focusing cavity, and a detonation combustion chamber, wherein the rotating air inlet disc is arranged on the detonation combustion chamber, the first air inlets are arranged on the side surface of the rotating air inlet disc, the second air inlets are arranged on the side surface of the shock wave focusing cavity, and the shock wave focusing cavity is arranged on the detonation combustion chamber; the rotating air inlet disc is arranged to rotate around the axis of the detonation combustion chamber, the first air inlets are arranged to be in periodic communication with the second air inlets, and the second air inlets are arranged to be in periodic communication with the first air inlets; when the first air inlets are in communication with the second air inlets, the external gas enters the shock wave focusing cavity through the first air inlets and the second air inlets under the action of the pressure difference between the internal and external gases, and a stable and reliable unsteady shock wave is generated in the shock wave focusing cavity; the generated plurality of unsteady shock waves propagate along a certain trajectory to the downstream detonation combustion chamber under the constraint of the horn-shaped shell, and are focused at the air outlet of the shock wave focusing cavity, thereby avoiding the pressure reversal phenomenon at the first air inlets, effectively overcoming the shock wave diffraction loss, reducing the shock wave focusing energy loss, and improving the reliability and working condition adaptability of the pulse detonation engine ignition initiation.

[0026] 2. Further, the shock wave focusing detonation initiation device provided by the present application is arranged to further limit the generated unsteady shock wave in the side bending channel by arranging the side bending channel in the shock wave focusing cavity and arranging the bending direction of the side bending channel to face the detonation combustion chamber, thereby further preventing the shock wave from reflecting back to the first air inlets, enabling all the unsteady shock waves to completely propagate to the downstream detonation combustion chamber, focusing at the air outlet of the shock wave focusing cavity, and further improving the focusing point energy.

[0027] 3. Further, the shock wave focusing detonation initiation device provided by the present application is arranged to have the same axial width of any first air inlet and any second air inlet, and the circumferential width of any first air inlet is greater than or equal to the circumferential width of any second air inlet, so that the external gas can more smoothly enter the shock wave focusing cavity through the communicated first air inlets and second air inlets under the action of the pressure difference, without escaping between the first air inlets and the second air inlets.

[0028] 4. Further, the shock wave focusing detonation initiation device provided by the present application is arranged to have N first air inlets uniformly distributed on the side surface circumference of the rotating air inlet disc, and N second air inlets uniformly distributed on the side surface circumference of the air disc, so that the process of periodic communication and disconnection of the N first air inlets and the N second air inlets is more stable and controllable.

[0029] 5. Further, the shock wave focusing detonation initiation device provided by the present application is arranged to have the shape of the detonation combustion chamber as an expanding nozzle shape, so that the combustible mixture after initiation can detonate downstream under the constraint of the detonation combustion chamber nozzle wall, thereby generating greater thrust.

[0030] 6. Further, the shock wave focusing detonation initiation device provided by the present application is arranged to be assembled through the gap cooperation between the rotating air inlet disc and the air disc, so as to avoid the propagation of the gas between the second air inlets, and enable the external gas to better enter the shock wave focusing cavity through the first air inlets and the second air inlets. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 A line frame diagram of the shock wave focusing detonation initiation device provided for the embodiment of the present application;

[0032] Figure 2 A line frame diagram of the air inlet rotating disc provided for the embodiment of the present application;

[0033] Figure 3 A line frame diagram of the shock wave focusing cavity provided for the embodiment of the present application. DETAILED DESCRIPTION

[0034] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application. In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0035] In order to achieve the above-mentioned purpose, the present application provides a shock wave focusing detonation initiation device, comprising: an air inlet rotating disc, a shock wave focusing cavity and a detonation combustion chamber arranged in sequence;

[0036] The air inlet rotating disc is a three-dimensional circular ring structure, and N first air inlets are arranged on the circumferential surface of the side surface thereof; N≥2;

[0037] The shock wave focusing cavity comprises an air inlet disc and a horn-shaped shell; the air inlet disc is a three-dimensional circular ring structure, coaxially arranged with the air inlet rotating disc and sleeved inside the air inlet rotating disc; N second air inlets are arranged on the circumferential surface of the side surface of the air inlet disc;

[0038] The end surface area of the air inlet disc is the same as the end surface area of the larger end of the horn-shaped shell; the end surface of the air inlet disc close to the air inlet rotating disc is closed, and the end surface away from the air inlet rotating disc is open and in communication with the larger end of the horn-shaped shell; the smaller end of the horn-shaped shell is provided with an air outlet (preferably, the smaller end of the horn-shaped shell directly serves as the air outlet of the shock wave focusing cavity), which is coaxially connected with the air inlet of the detonation combustion chamber;

[0039] The air inlet rotating disc rotates under external driving and moves relatively with the stationary shock wave focusing cavity, so that the N first air inlets and the N second air inlets are periodically connected and disconnected, the ignition point for detonation initiation is generated when connected to initiate the combustible mixture in the detonation combustion chamber, and the exhaust of combustion products and the filling of the combustible mixture in the next cycle are performed when disconnected.

[0040] The shock wave focusing detonation initiation device is designed, the first air inlet on the air inlet rotating disc is periodically connected and cut off with the second air inlet on the shock wave focusing cavity through rotating the air inlet rotating disc, when connected, the stable and reliable unsteady shock wave is generated in the shock wave focusing cavity under the action of the internal and external gas pressure difference, and all the unsteady shock waves are propagated to the downstream detonation combustion chamber according to a certain trajectory under the constraint of the horn-shaped shell, and are focused at the air outlet of the shock wave focusing cavity, the pressure reversal phenomenon at the first air inlet is avoided, the shock wave diffraction loss is effectively overcome, the shock wave focusing energy loss is reduced, one or more local high-temperature and high-pressure hot spots are generated, and the reliability and working condition adaptability of the pulse detonation engine ignition initiation are improved.

[0041] It should be noted that the horn-shaped shell can be a non-axisymmetric structure or an axisymmetric structure; preferably, the horn-shaped shell is an axisymmetric structure and is coaxially arranged with the air inlet disc.

[0042] In an optional embodiment, the shock wave focusing cavity is further provided with N side bending channels; one end of the N side bending channels is connected with the N second air inlets one by one, and the other end is connected with the air outlet after converging together; wherein the bending direction of the N side bending channels is towards the detonation combustion chamber.

[0043] By arranging the side bending channels in the shock wave focusing cavity, and the bending direction of the side bending channels is towards the detonation combustion chamber, the generated unsteady shock wave can be further limited in the side bending channels, the reflection of the shock wave back to the first air inlet is further prevented, so that all the unsteady shock waves can completely propagate to the downstream detonation combustion chamber, focus at the air outlet of the shock wave focusing cavity, and the focusing point energy is further improved.

[0044] In an optional embodiment, the axial width of any first air inlet is the same as the axial width of any second air inlet; the circumferential width of any first air inlet is greater than or equal to the circumferential width of any second air inlet. Preferably, the axial width of the second air inlet is the same as the circumferential width of the side surface of the air inlet disc.

[0045] It should be noted that the N first air inlets can be uniformly distributed or non-uniformly distributed on the side circumference of the air inlet disc, and the N second air inlets can be uniformly distributed or non-uniformly distributed on the side circumference of the air inlet disc; the distribution characteristics of the N first air inlets on the side circumference of the air inlet disc are the same as the distribution characteristics of the N second air inlets on the side circumference of the air inlet disc, and when the N first air inlets and the N second air inlets are both non-uniformly distributed, the N first air inlets and the N second air inlets are one-to-one corresponding. Preferably, in order to make the whole process more stable and controllable, in an optional embodiment, the N first air inlets are uniformly distributed on the side circumference of the air inlet disc; the N second air inlets are uniformly distributed on the side circumference of the air inlet disc; the central angle corresponding to any two adjacent first air inlets is the same as the central angle corresponding to any two adjacent second air inlets. Preferably, the N first air inlets are the same size; the N second air inlets are the same size.

[0046] In an optional embodiment, the N first air inlets are the same size; the circumferential width of the first air inlet The circumferential spacing between any two adjacent first air inlets satisfies:

[0047]

[0048] wherein, is the inner ring radius of the air inlet disc; is the radius of the horn-shaped shell air outlet; is the adiabatic index; is the gas constant; is the rotational speed of the air inlet disc, in rpm; T 1 and T 2 are the gas temperatures in the shock wave focusing cavity before and after the unsteady shock wave sweeping through the shock wave focusing cavity when the N first air inlets and the N second air inlets are connected.

[0049] In an optional embodiment, the circumferential width of the first air inlet corresponds to a central angle of 2° to 20°; the circumferential width of the second air inlet corresponds to a central angle of 2° to 20°.

[0050] It should be noted that the shapes of the first air inlets and the second air inlets can be cubes, cuboids, cylinders, etc., which are not limited here. Preferably, in an optional embodiment, the shapes of the first air inlets and the second air inlets are both cuboids.

[0051] It should be noted that the shape of the detonation combustion chamber can be straight cylinder, cylindrical, expanding nozzle shape, etc. In an alternative embodiment, the shape of the detonation combustion chamber is an expanding nozzle shape, so that the ignited combustible mixture is detonated downstream under the constraint of the detonation combustion chamber nozzle wall, thereby generating greater thrust.

[0052] In an alternative embodiment, the intake disc and the intake disc are assembled through the gap cooperation to avoid the propagation of gas between the second air inlets, so that the external gas can enter the shock focusing cavity through the first air inlets and the second air inlets.

[0053] In order to further illustrate the shock focusing detonation initiation device provided by the first aspect of the present application, a specific embodiment is described in detail below:

[0054] As shown in Figure 1 , the shock focusing detonation initiation device provided by the present embodiment mainly comprises: an intake disc 9, a shock focusing cavity 3 and a detonation combustion chamber 5; wherein the shape of the detonation combustion chamber 5 is an expanding nozzle shape.

[0055] As shown in Figure 2 , the line frame diagram of the intake disc, the intake disc is a three-dimensional circular ring structure, and N first air inlets 2 (high pressure air inlets) are evenly distributed on the side circumference; the N first air inlets 2 are the same size, all of which are cuboid structure; N≥2, in the present embodiment, 12 are set;

[0056] As shown in Figure 3 , the line frame diagram of the shock focusing cavity, wherein the left drawing is the front view line frame diagram of the shock focusing cavity, and the right drawing is the side view line frame diagram of the shock focusing cavity; the shock focusing cavity comprises an air inlet disc and a horn-shaped shell; the air inlet disc is a three-dimensional circular ring structure, coaxially arranged with the intake disc, and sleeved in the inside of the intake disc 9, and assembled with the intake disc 9 through gap cooperation. N second air inlets 8 (jet air inlets) are evenly distributed on the side circumference of the air inlet disc; the N second air inlets 8 are the same size, all of which are cuboid structure; the horn-shaped shell is an axisymmetric structure, and is coaxially arranged with the air inlet disc; the end surface area of the air inlet disc is the same as the end surface area of the larger end of the horn-shaped shell; the end surface of the air inlet disc close to the intake disc is closed, and the end surface away from the intake disc is open and communicated with the larger end of the horn-shaped shell; the smaller end of the horn-shaped shell is provided with an air outlet, which is coaxially connected with the air inlet 6 of the detonation combustion chamber 5;

[0057] When the shock wave focusing detonation initiation device is working, the motor 1 drives the rotating air inlet disc 9 to rotate at a certain speed. The relative movement between the rotating air inlet disc 9 and the static shock wave focusing cavity 3 realizes the periodic connection and disconnection of the first air inlet 2 and the second air inlet 8, and the physical state discontinuity condition formed by the shock wave is generated. When the first air inlet 2 and the second air inlet 8 are connected, the external high-pressure gas enters the shock wave focusing cavity 3 through the first air inlet 2 and the second air inlet 8 in sequence under the action of the pressure difference, and the unsteady shock wave moving towards the shaft center is generated. A total of N unsteady shock waves moving towards the shaft center are generated. The unsteady shock waves are focused at the air outlet 6 of the shock wave focusing cavity 3 without significant diffraction loss, and the high-temperature and high-pressure ignition point for direct detonation initiation is generated. The combustible mixture in the detonation combustion chamber is initiated, and the ignited combustible mixture is detonated downstream under the constraint of the nozzle wall 4 of the detonation combustion chamber 5 to generate thrust.

[0058] When the first air inlet 2 and the second air inlet 8 are disconnected, the exhaust of the combustion products and the filling of the combustible mixture in the next cycle are completed. When the first air inlet 2 and the second air inlet 8 are rotated to be connected again, the above-mentioned unsteady shock wave propagation and focusing process is generated again, and the newly filled combustible mixture is ignited and initiated again. The above-mentioned process is repeated, high-frequency detonation combustion is carried out in the shock wave focusing detonation initiation device, and continuous control of the thrust is realized.

[0059] In a second aspect, the present application provides a control method of the shock wave focusing detonation initiation device provided in the first aspect of the present application, comprising:

[0060] The air inlet disc is driven to rotate, so that the relative movement between the air inlet disc and the static shock wave focusing cavity is generated, and the N first air inlets and the N second air inlets are periodically connected and disconnected.

[0061] When the N first air inlets and the N second air inlets are connected, the external gas enters the shock wave focusing cavity through each set of connected first air inlets and second air inlets under the action of the pressure difference to generate unsteady shock waves. The N unsteady shock waves are focused at the air outlet of the shock wave focusing cavity, and the ignition point for detonation initiation is generated to initiate the combustible mixture in the detonation combustion chamber.

[0062] When the N first air inlets and the N second air inlets are disconnected, the exhaust of the combustion products and the filling of the combustible mixture in the next cycle are carried out.

[0063] In an optional embodiment, the rotating speed of the air inlet disc is controlled, so that the generation frequency of the unsteady shock waves is controlled, a certain frequency of high-temperature and high-pressure hot spots is generated in the shock wave focusing cavity by generating the unsteady shock waves and focusing, and the frequency of the ignition point for detonation initiation generated at the air outlet of the shock wave focusing cavity is controlled.

[0064] The present application avoids shock wave reversal while making the energy of the focused shock wave greater, thereby improving the reliability and working condition adaptability of the ignition and detonation of the pulse detonation engine.

[0065] The related technical solution is the same as the shock wave focusing detonation ignition device provided by the first aspect of the present application, which will not be described here.

[0066] Those skilled in the art will readily understand that the above description is only the preferred embodiment of the present application and is not intended to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A shock wave focusing detonation initiation device, characterized in that: include: An air intake turntable, a shock wave focusing cavity and a detonation combustion chamber are arranged in sequence; The air inlet turntable is a three-dimensional circular structure, and N first air inlets are provided on the circumference of its side surface; N ≥ 2; The shock wave focusing cavity includes an air inlet disk and a trumpet-shaped shell; the air inlet disk is a three-dimensional circular ring structure, coaxially arranged with the air inlet turntable and sleeved inside the air inlet turntable; N second air inlets are provided on the side circumference of the air inlet disk; The end surface area of ​​the air intake disc is the same as the end surface area of ​​the larger end of the trumpet-shaped housing; the end surface of the air intake disc close to the air intake turntable is closed, and the end surface away from the air intake turntable is open and communicated with the larger end of the trumpet-shaped housing; the smaller end of the trumpet-shaped housing is provided with an air outlet, which is coaxially connected to the air intake of the detonation combustion chamber; and the air outlet is communicated with the second air intake; The air intake turntable rotates under external drive and moves relative to the stationary shock wave focusing cavity, so that the N first air intake ports and the N second air intake ports are periodically connected and disconnected. When connected, an ignition point for detonation is generated to detonate the combustible mixture in the detonation combustion chamber. When disconnected, the combustion products are exhausted and the combustible mixture is filled in the next cycle.

2. The shock wave focusing detonation initiation device according to claim 1, characterized in that: The shock wave focusing cavity is also provided with: N side bending channels; one end of the N side bending channels is connected to the N second air inlets in a one-to-one correspondence, and the other end converges together and is connected to the air outlet; wherein the bending direction of the N side bending channels is toward the detonation combustion chamber.

3. The shock wave focusing detonation initiation device according to claim 1, characterized in that: An axial width of any of the first air inlets is the same as an axial width of any of the second air inlets; a circumferential width of any of the first air inlets is greater than or equal to a circumferential width of any of the second air inlets.

4. The shock wave focusing detonation initiation device according to claim 3, characterized in that: N first air inlets are evenly distributed on the side circumference of the air inlet turntable; N second air inlets are evenly distributed on the side circumference of the air inlet disk; the central angle corresponding to any two adjacent first air inlets is the same as the central angle corresponding to any two adjacent second air inlets.

5. The shock wave focusing detonation initiation device according to claim 4, characterized in that: The N first air inlets are of the same size; the circumferential width of the first air inlet is The circumferential distance between any two adjacent first air inlets is satisfy: in, is the inner ring radius of the air intake disk; is the air outlet radius of the trumpet-shaped housing; is the adiabatic index; is the gas constant; is the rotation speed of the air intake turntable, in revolutions per minute; T 1 and T 2 are the gas temperatures in the shock focusing cavity before and after the unsteady shock wave generated in the shock focusing cavity sweeps through the shock focusing cavity when the N first air inlets are connected to the N second air inlets.

6. The shock wave focusing detonation initiator according to any one of claims 1 to 5, characterized in that: The central angle corresponding to the circumferential width of the first air inlet is 2°~20°; the central angle corresponding to the circumferential width of the second air inlet is 2°~20°.

7. The shock wave focusing detonation initiation device according to any one of claims 1 to 5, characterized in that: The detonation combustion chamber has an extended nozzle shape.

8. The shock wave focusing detonation initiation device according to any one of claims 1 to 5, characterized in that: The air intake turntable and the air intake disc are assembled through clearance fit.

9. The control method of the shock wave focusing detonation initiation device according to any one of claims 1 to 8, characterized in that: include: The air inlet turntable is driven to rotate, thereby generating relative motion with the stationary shock focusing cavity, so that the N first air inlets are periodically connected and disconnected with the N second air inlets; When the N first air inlets are connected to the N second air inlets, external gas enters the shock wave focusing cavity through each set of connected first air inlets and second air inlets under the action of pressure difference, generating unsteady shock waves; the N unsteady shock waves are focused at the air outlet of the shock wave focusing cavity, generating ignition points for detonation initiation, thereby detonating the combustible mixture in the detonation combustion chamber; When the N first air intake ports are disconnected from the N second air intake ports, exhaust of combustion products and filling of combustible mixture for the next cycle are performed.

10. The control method according to claim 9, characterized in that: The rotation speed of the air inlet turntable is controlled, thereby controlling the frequency of the unsteady shock wave generation, and further controlling the frequency of the detonation initiation ignition point generated at the outlet of the shock wave focusing cavity.

Images