Rotary detonation combustion chamber injection device with air mixing circular seam

Abstract

The invention provides a rotary detonation combustion chamber injection device with an air mixing circular seam. The rotary detonation combustion chamber injection device comprises an oxidizing agent circular seam, a fuel injection hole and the air mixing circular seam. The application object of the device is a rotary detonation combustion chamber, and the device is arranged at one end of an annular flow channel of the rotary detonation combustion chamber. In a working state, the air mixing circular seam starts supplying while the oxidizing agent circular seam and the fuel spraying hole supply normally. When rotating detonation waves propagate in the combustion chamber, the detonation waves are locally decoupled in the radial direction of the combustion chamber due to the fact that no fuel exists in the downstream position of the air mixing circular seam, and the pressure and the temperature are both reduced; the air and detonation wave combustion products are mixed at the head of the combustion chamber, and the temperature of the products is further reduced. Under the condition that the supply conditions of an oxidizing agent, fuel and mixed air are fixed, the rotating detonation wave propagation process and the air mixing process reach dynamic balance, the pressure and temperature of combustion products near an outer ring and an inner ring of a combustion chamber are reduced, and the uniformity of fuel gas parameters at an outlet of the combustion chamber is improved.

Description

Technical Field

[0001] This invention relates to a rotary detonation combustion chamber injection device with an air-mixing annular slit, and is situated in the field of rotary detonation combustion. Background Technology

[0002] Detonation combustion is characterized by its rapid combustion speed and self-pressurization. A rotating detonation combustor is a type of combustor based on detonation combustion. Its operation involves the oxidizer and fuel entering from the combustion chamber head. After ignition and detonation, a detonation wave propagates circumferentially within the combustion chamber, periodically consuming the reactants. The combustion products are discharged from the combustion chamber outlet and used to drive the turbine or directly generate thrust. Compared to traditional gas turbine engine combustors, rotating detonation combustors have advantages such as simpler structure and shorter combustion chamber length, making them a research hotspot in the aerospace propulsion field.

[0003] Rotating detonation waves propagate circumferentially within the combustion chamber, exhibiting significant pressure and temperature gradients along this direction. Consequently, there is severe circumferential inhomogeneity in the pressure and temperature parameters of the gas flow inside and at the outlet of the combustion chamber. Existing research indicates that circumferential inhomogeneity significantly impacts the work efficiency of the outlet gas, and periodic fluctuations in the thermal load on the combustion chamber walls can also cause thermal fatigue. For downstream components of the rotating detonation combustion chamber, the non-uniformity of high-temperature gas parameters will affect their performance and lifespan. Increasing the mixing of air at the head of the rotating detonation combustion chamber can reduce the gas temperature before it leaves the outlet, weakening the circumferential inhomogeneity of the flow and thus mitigating the aforementioned negative impacts.

[0004] In conventional gas turbine combustors, the mixed air inlet is located on the middle and rear wall of the combustor flame tube. For rotating detonation combustors, the detonation combustion process is concentrated at the combustor head, where the wall heat load is greatest. Therefore, the mixed air inlet should be close to the combustor head. However, the closer to the combustor head, the more severe the interference from detonation wave pressure on the intake process. Since the high-pressure products after the detonation wave pass will block the intake process, the supply pressure must be increased to ensure mixed air intake, which will increase the total pressure loss during the intake process. Furthermore, as the combustor wall is a major pressure-bearing component, the presence of mixing holes in the wall will affect the structural strength of the combustor, making it less able to withstand the periodic pressure fluctuations caused by rotating detonation waves.

[0005] To address the above problems, this invention proposes a rotary detonation combustion chamber injection device with an air-mixing annular slit. As an optimized solution for conventional rotary detonation combustion chamber injection devices, it integrates the air-mixing inlet with the detonation reactant inlet, enabling the introduction of mixed air without altering the combustion chamber wall, thus solving the problems of thermal protection and uneven circumferential distribution of exhaust gas in the rotary detonation combustion chamber. Summary of the Invention

[0006] This invention provides a rotary detonation combustion chamber injection device with an air-mixing annular slit. It is applied to rotary detonation combustion chambers. By introducing mixed air from the head of the combustion chamber, it reduces the heat load on the combustion chamber wall and the circumferential non-uniformity of the outlet gas, thereby extending the service life of the combustion chamber and its downstream components.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A rotary detonation combustion chamber injection device with an air-mixing annular slot includes an oxidizer annular slot, a fuel injection port, and an air-mixing annular slot. Its features are: the oxidizer annular slot is located on the head end face of the rotary detonation combustion chamber for supplying oxidizer into the combustion chamber; the fuel injection port is located on the inner wall surface at the outlet of the oxidizer annular slot, and consists of several circumferentially distributed injection ports, with the central axis of the injection port perpendicular to the air intake direction of the oxidizer annular slot, for supplying fuel into the rotary detonation combustion chamber; the geometric parameters of the oxidizer annular slot and the fuel injection port should meet the following conditions: (mm) in, D o The diameter of the oxidant ring gap. D c For the outer diameter of the rotating detonation combustion chamber, h o The width of the oxidant circumferential slit. D f The diameter of the fuel injection nozzle. n f This refers to the number of fuel injection holes. The mixed air annular slots are located on both sides of the oxidizer annular slot, used to supply mixed air into the rotating detonation combustion chamber to mix with the detonation combustion products, reducing the heat load on the combustion chamber walls and the circumferential non-uniformity of the outlet combustion gases. The geometric parameters of the mixed air annular slots should meet the following conditions: in, h a The width of the air-mixed annular gap.

[0008] This invention relates to a rotating detonation combustor. A conventional annular rotating detonation combustor is cylindrical in shape, consisting of an outer ring, an inner column, and an ignition device. The outer ring and inner column are coaxial, forming an annular flow channel for the periodic propagation of the rotating detonation wave. The ignition device is located on the outer ring wall for ignition and detonation. During operation, the oxidizer and fuel enter the combustor from one end of the annular flow channel. After ignition, a circumferentially rotating detonation wave is generated at the head of the combustor. As the rotating detonation wave passes, the high pressure halts the injection process. After the post-wave products expand, the pressure decreases, and the oxidizer and fuel supply resumes. A certain height of reactant mixture is filled axially for the rotating detonation wave to burn and consume in the next cycle. The combustion products are discharged from the other end of the annular flow channel.

[0009] This invention is located at one end of the annular flow channel of a rotary detonation combustor. In the initial state, the oxidizer annular slot and fuel injection orifice are supplied normally, while the mixed air annular slot is closed, consistent with the state of a conventional rotary detonation combustor. In the operating state, the oxidizer annular slot and fuel injection orifice are supplied normally, while the mixed air annular slot is open. When the rotary detonation wave propagates within the combustor, since there is no fuel downstream of the mixed air annular slot, the detonation wave will be locally decoupled in the radial direction of the combustor, resulting in a decrease in both pressure and temperature. The mixed air and the combustion products following the detonation wave are mixed at the head of the combustor, further reducing the product temperature. Under constant oxidizer, fuel, and mixed air supply conditions, the propagation process of the rotary detonation wave and the air mixing process will reach a dynamic equilibrium, reducing the pressure and temperature of the combustion products near the outer and inner annular rings of the combustor and improving the uniformity of the combustion chamber outlet gas parameters.

[0010] Beneficial effects: The rotary detonation combustion chamber injection device with mixed air annular gap provided by the present invention can introduce mixed air without changing the combustion chamber wall surface. The mixing process is set in the combustion chamber head area where the detonation wave is located, which can effectively reduce the heat load on the combustion chamber wall surface and improve the uniformity of the outlet gas parameters. Attached Figure Description

[0011] Figure 1 A schematic diagram of a rotary detonation combustion chamber equipped with the present invention; Figure 2 A schematic diagram of the propagation and mixing process of detonation waves in a rotating detonation combustion chamber; Figure 3 This is a schematic diagram of the invention applied to a rotating detonation combustion chamber; Figure 4 This is a schematic diagram of the application of the present invention to a rotary detonation engine; Among them, 1 is the oxidizer annular gap, 2 is the fuel injection hole, 3 is the mixed air annular gap, 4 is the outer ring of the combustion chamber, 5 is the inner column of the combustion chamber, 6 is the ignition device, 7 is the nozzle, 8 is the rotating detonation wave, and 9 is the mixing zone. Detailed Implementation

[0012] The present invention will be further described below with reference to the accompanying drawings and specific implementation process.

[0013] like Figure 1 As shown, the application of this invention is a rotating detonation combustion chamber, which consists of an outer ring 4, an inner column 5, and an ignition device 6. The rotating detonation combustion chamber and the nozzle 7 together form the rotating detonation engine body. The outer ring 4 and the inner column 5 are coaxial, forming an annular flow channel for the periodic propagation of rotating detonation waves; the ignition device 6 is disposed on the outer ring wall of the combustion chamber for ignition and detonation. Figure 2 This is a schematic diagram of the working process of the rotating detonation combustion chamber. After ignition and detonation, a circumferentially propagating rotating detonation wave 8 will be formed at the head of the combustion chamber. When the rotating detonation wave passes by, the high pressure will stop the injection process. After the product expands behind the wave, the pressure decreases, and the oxidant and fuel supply process resumes. A certain height of reactant mixture is filled in the axial direction to be consumed by the rotating detonation wave in the next cycle. The combustion products are discharged from the other end of the annular flow channel.

[0014] This invention comprises an oxidizer annular slot 1, a fuel injection orifice 2, and a mixed air annular slot 3, disposed at one end of the annular flow channel of a rotary detonation combustion chamber. In the initial state, the oxidizer annular slot 1 and fuel injection orifice 2 are supplied normally, while the mixed air annular slot 3 is closed, consistent with the state of a conventional rotary detonation combustion chamber. In the operating state, the oxidizer annular slot 1 and fuel injection orifice 2 are supplied normally, while the mixed air annular slot 3 is opened for supply. Figure 2 As shown, when the rotating detonation wave 8 propagates in the combustion chamber, since there is no fuel downstream of the air mixing ring gap, the detonation wave will be partially decoupled in the radial direction of the combustion chamber. The air mixing and the combustion products after the detonation wave are mixed in the mixing zone 9, which reduces the pressure and temperature of the combustion products near the outer and inner rings of the combustion chamber and improves the uniformity of the combustion chamber outlet gas parameters.

[0015] Example 1: See Figure 3 In the application of this invention to a rotating detonation combustor, the rotating detonation combustor consists of an outer ring 4, an inner column 5, and an ignition device 6. This invention is located at one end of the combustor flow channel and consists of an oxidizer annular slot 1, a fuel injection port 2, and an air-mixing annular slot 3. During operation, the air-mixing annular slot 3 introduces mixed air into the combustor, reducing the pressure and temperature of combustion products near the outer and inner rings of the combustor, and improving the uniformity of the combustion gas parameters at the combustor outlet.

[0016] Example 2: See Figure 4 In the application of this invention to a rotary detonation engine, the rotary detonation combustion chamber consists of an outer ring 4, an inner column 5, and an ignition device 6, which, together with the nozzle 7, constitute the main body of the rotary detonation engine. This invention is located at one end of the combustion chamber flow channel and consists of an oxidizer annular slot 1, a fuel injection hole 2, and a mixed air annular slot 3. During operation, the mixed air annular slot 3 introduces mixed air into the combustion chamber, reducing the pressure and temperature of combustion products near the outer and inner rings of the combustion chamber, and improving the uniformity of the combustion chamber outlet gas parameters.

Claims

1. A rotating detonation combustion chamber injection device with a dilution air ring slot, comprising an oxidizer ring slot, a fuel injection orifice, and a dilution air ring slot. Characterized by: The oxidant ring gap is arranged on the end face of the head of the rotary detonation combustion chamber, and is used for supplying the oxidant into the rotary detonation combustion chamber. The fuel injection hole is located on the inner side wall surface at the outlet of the oxidant ring gap, is a plurality of injection holes uniformly distributed in the circumferential direction, and has a central axis perpendicular to the direction of the oxidant ring gap. The fuel injection hole is used for supplying the fuel into the rotary detonation combustion chamber. The geometric parameters of the oxidant ring gap and the fuel injection hole should satisfy the following conditions: (mm) wherein, D o is the oxidizer annulus inner diameter, D c is the rotary detonation chamber outer diameter, h o is the oxidizer annulus width, D f is the fuel injector diameter, n f is the number of fuel injectors. The dilution air annulus is located inside and outside the oxidizer annulus for supplying dilution air into the rotary detonation chamber to mix with the detonation combustion products to reduce the chamber wall heat load and the circumferential non-uniformity of the outlet gas. The geometric parameters of the dilution air annulus should satisfy the following conditions: wherein h a is the width of the air blending annulus. The injection device of the rotary detonation combustion chamber with the air mixing ring gap is arranged at one end of the annular flow channel of the rotary detonation combustion chamber, and is applied to the rotary detonation combustion chamber. In the initial state, the oxidant ring gap and the fuel injection hole are normally supplied, and the air mixing ring gap is closed to supply, which is consistent with the state of the conventional rotary detonation combustion chamber. In the working state, the oxidant ring gap and the fuel injection hole are normally supplied, and the air mixing ring gap is opened to supply. When the rotary detonation wave propagates in the combustion chamber, the detonation wave will be partially decoupled in the radial direction of the combustion chamber due to the absence of fuel at the downstream position of the air mixing ring gap, and the pressure and temperature are reduced. The air mixing and the detonation wave afterburning product are mixed in the head of the combustion chamber, and the product temperature is further reduced. Under the condition that the supply of the oxidant, the fuel and the air mixing is certain, the rotary detonation wave propagation process and the air mixing process will reach a dynamic balance, the pressure and temperature of the combustion products near the outer ring and the inner ring of the combustion chamber are reduced, and the uniformity of the gas parameters at the outlet of the combustion chamber is improved.

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