A device for increasing the number of rotational detonation waves

Abstract

This invention proposes a device for increasing the number of rotating detonation waves, comprising a hot spot cavity, a piston rod, and a controller. The device is applied to a rotating detonation combustion chamber, located on the outer wall of the combustion chamber and connected to the interior. During operation, the controller raises the piston rod to its highest position, increasing the volume of the hot spot cavity. When the rotating detonation wave propagates inside the combustion chamber and passes through the hot spot cavity, high-temperature combustion products enter and remain within it. After the rotating detonation wave passes, as reactants begin to fill the cavity axially, reaching the hot spot cavity, the combustion products remaining within it ignite the reactants prematurely, developing into new rotating detonation waves. After a certain period, these new waves coexist stably with the existing rotating detonation waves, thus increasing the number of rotating detonation waves within the combustion chamber.

Description

Technical Field

[0001] This invention relates to a device for increasing the number of rotating detonation waves, and is relevant to the field of rotating detonation engines. Background Technology

[0002] Detonation combustion is a combustion form that couples chemical reactions with shock waves, characterized by rapid flame propagation, self-pressurization, and high heat release rates. A rotating detonation combustor is a combustion chamber concept based on detonation combustion. Its operation involves reactants entering from the head of the rotating detonation combustor, igniting, and forming a circumferentially rotating detonation wave within the combustion chamber, continuously consuming the reactants. Combustion products are discharged from the tail of the combustion chamber and accelerated through a nozzle, increasing thrust. Rotating detonation engines, with rotating detonation combustors and nozzles as their core components, have a simpler structure and a wider theoretical operating range than traditional gas turbine engines, and are currently a research hotspot in the aerospace propulsion field. Furthermore, there are applications that combine rotating detonation combustors with gas turbine engines, namely rotating detonation turbine engines, where the rotating detonation combustor replaces the conventional main combustion chamber to generate gas and drive the turbine.

[0003] Because rotating detonation waves exhibit significant pressure and temperature gradients along their propagation direction, severe circumferential non-uniformity in the combustion chamber outlet gas parameters will occur regardless of the application. Existing research indicates that circumferential non-uniformity of the combustion chamber outlet gas affects nozzle efficiency and reduces the propulsive performance of rotating detonation engines; non-uniform inflow leads to inhomogeneity in the turbine interior and downstream flow field, impacting component performance and service life. Increasing the number of rotating detonation waves within the combustion chamber can, to some extent, reduce the degree of non-uniformity in the outlet flow field.

[0004] It is generally believed that the number of rotating detonation waves in the combustion chamber can be adjusted by changing the combustion chamber structure or the combustion chamber supply conditions. Changing the combustion chamber structure, adjusting the width and configuration, can vary the number of rotating detonation waves, but this requires movable components within the combustion chamber, increasing system complexity and reducing reliability. Changing the combustion chamber supply conditions, adjusting the reactant flow rate, can also vary the number of rotating detonation waves, but this restricts upstream flow conditions and reduces the theoretical operating range of the combustion chamber. Therefore, both of these methods of adjusting the number of rotating detonation waves significantly impact combustion chamber performance. This invention provides a device for increasing the number of rotating detonation waves, which can be used as an auxiliary device for rotating detonation combustion chambers. Without changing the combustion chamber structure and supply conditions, it increases the number of rotating detonation waves in the combustion chamber, effectively solving the problem of circumferential non-uniformity in the outlet flow field. This has significant implications for the engineering application of rotating detonation combustion chambers. Summary of the Invention

[0005] The purpose of this invention is to provide a device that can increase the number of rotating detonation waves. Its application is in rotating detonation combustion chambers. By generating more detonation waves that propagate in the same direction in the combustion chamber, the circumferential non-uniformity of the combustion chamber outlet is improved, thereby enabling rotating detonation engines to obtain better propulsion performance; and the turbine heat load distribution of rotating detonation turbine engines is made more uniform, thus extending the service life of components.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A device for increasing the number of rotating detonation waves includes a hot spot cavity, a piston rod, and a controller. The hot spot cavity is characterized by having a hollow cylindrical structure inside, positioned on and penetrating the outer wall of the rotating detonation combustion chamber, and communicating with the interior of the combustion chamber. The geometric parameters of the hot spot cavity should meet the following conditions:

[0008]

[0009]

[0010] Where d is the diameter of the cylindrical surface inside the hot spot cavity, D is the outer diameter of the rotating detonation combustor, and h is the height of the cylindrical surface inside the hot spot cavity. The axial position of the hot spot cavity on the outer wall of the combustor is adjacent to the head of the combustor. The piston rod is located inside the hot spot cavity, and the piston head is in close contact with the inner surface of the hot spot cavity to form a seal. It can move along the central axis of the cylindrical surface inside the hot spot cavity to change the volume of the hot spot cavity. The controller is fixedly connected to the hot spot cavity and connected to the tail of the piston rod. It is used to control the piston rod to actuate and change its position, thereby adjusting the volume of the hot spot cavity.

[0011] The present invention relates to a rotating detonation combustion chamber. The rotating detonation combustion chamber is cylindrical in shape and consists of an outer combustion chamber ring, an inner combustion chamber head ring, an inner combustion chamber column, and an ignition device. The outer combustion chamber ring and the inner combustion chamber head ring are coaxial, forming a "ring-slit-orifice" type channel for the reactants to enter the combustion chamber. The inner combustion chamber column is a cylinder with a tail cone, coaxially connected to the outer combustion chamber head ring. The annular cavity formed by the outer combustion chamber ring and the inner combustion chamber column is the rotating detonation combustion zone. The ignition device is located on the outer wall of the outer combustion chamber ring and is used for ignition and detonation. During operation, the reactants enter the combustion chamber through the "ring-slit-orifice" type channel. After ignition, a circumferentially propagating rotating detonation wave is generated at the combustion chamber head. After the rotating detonation wave passes, the reactant supply to the combustion chamber head will experience a local stagnation-recovery process, and a certain height of reactants will be filled axially to maintain the periodic propagation of the detonation wave.

[0012] This invention is installed on the outer wall of the rotating detonation combustion chamber and communicates with the interior of the combustion chamber. Under normal conditions, the piston rod head is flush with the inner wall of the outer ring of the combustion chamber, and the volume of the hot spot cavity communicating with the rotating detonation combustion chamber is zero. During operation, the controller raises the piston rod to its highest position, increasing the volume of the hot spot cavity. When the rotating detonation wave propagates inside the combustion chamber and passes through the location of the hot spot cavity, high-temperature combustion products enter the hot spot cavity and remain there. After the rotating detonation wave passes, when the reactants begin to fill axially and reach the location of the hot spot cavity, the combustion products remaining in the hot spot cavity will ignite the reactants prematurely and develop into a new rotating detonation wave. After a certain period, this new wave stably coexists with the original rotating detonation wave, thereby increasing the number of rotating detonation waves in the combustion chamber. Under certain conditions of combustion chamber configuration and incoming flow, the propagation process of rotating detonation wave and the filling process of reactants will reach a dynamic equilibrium, and the number of detonation waves will remain unchanged. This invention is equivalent to establishing a stable ignition source in the combustion chamber, inducing the propagation process of rotating detonation wave and the filling process of reactants to reach a new equilibrium, thereby increasing the number of detonation waves.

[0013] Beneficial effects:

[0014] The device for increasing the number of rotating detonation waves provided by this invention can increase the number of rotating detonation waves in the rotating detonation combustion chamber under unchanged supply conditions, effectively improving the circumferential non-uniformity at the outlet and reducing the impact on component life and overall combustion chamber performance. Attached Figure Description

[0015] Figure 1 A schematic diagram of a rotary detonation engine equipped with the present invention;

[0016] Figure 2 A schematic diagram of the propagation process of rotating detonation waves in a rotating detonation combustion chamber;

[0017] Figure 3 A schematic diagram of a rotary detonation engine with the piston rod in its initial position;

[0018] Figure 4 A schematic diagram of a rotary detonation engine with the piston rod in the working position;

[0019] Figure 5 A schematic diagram of a rotating detonation combustion chamber with the piston rod in its initial position;

[0020] Figure 6 A schematic diagram of a rotating detonation combustion chamber when the piston rod is in the working position;

[0021] Among them, 1 is the outer ring of the combustion chamber, 2 is the inner ring of the combustion chamber head, 3 is the hot spot cavity, 4 is the piston rod, 5 is the nozzle, 6 is the inner column of the combustion chamber, 7 is the ignition device, 8 is the controller, and 9 is the rotating detonation wave. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and specific implementation process.

[0023] like Figure 1 As shown, the application of this invention is a rotary detonation combustion chamber, which consists of an outer combustion chamber ring 1, an inner combustion chamber head ring 2, an inner combustion chamber column 6, and an ignition device 7. The rotary detonation combustion chamber and the nozzle 5 together form a rotary detonation engine. The outer combustion chamber ring 1 and the inner combustion chamber head ring 2 are coaxial, forming an "annular slot-nozzle" type channel for reactants to enter the combustion chamber. The inner combustion chamber column 6 is a cylinder with a tail cone, coaxially connected to the outer combustion chamber head ring. The annular cavity formed by the outer combustion chamber ring 1 and the inner combustion chamber column 6 is the rotary detonation combustion zone. The ignition device 7 is disposed on the outer wall of the outer combustion chamber ring and is used for ignition and detonation. Figure 2 The simulation diagram shows the internal flow field of the rotating detonation combustion chamber. During operation, the reactants enter the combustion chamber through the "annular slot-nozzle" type channel. After ignition, a circumferentially propagating rotating detonation wave 9 is generated at the head of the combustion chamber. After the rotating detonation wave 9 passes, due to the high pressure, the supply of reactants at the head of the combustion chamber will experience a local stagnation-recovery process, and a certain height of reactants will be filled in the axial direction to maintain the rotational propagation of the rotating detonation wave 9 in the next cycle.

[0024] The main body of this invention consists of a hot spot cavity 3, a piston rod 4, and a controller 8. It is located on the outer wall of the rotating detonation combustion chamber and communicates with the interior of the combustion chamber. Under normal conditions, the head of the piston rod 4 is flush with the inner wall of the outer ring 1 of the combustion chamber, and the volume of the hot spot cavity 3 communicating with the rotating detonation combustion chamber is zero. In operation, the controller 8 raises the piston rod 4 to its highest position, increasing the volume of the hot spot cavity 3. When the rotating detonation wave 9 propagates within the combustion chamber and passes through the location of the hot spot cavity 3, high-temperature combustion products enter the interior of the hot spot cavity 3 and remain there. After the rotating detonation wave 9 passes, when the reactants begin to fill axially and reach the location of the hot spot cavity 3, the combustion products remaining in the hot spot cavity 3 ignite the reactants and develop into new rotating detonation waves 9, which coexist stably with the original rotating detonation waves 9, thereby increasing the number of rotating detonation waves 9 within the combustion chamber.

[0025] To facilitate observation of the position of piston rod 4, the structure of controller 8 is not shown in the following embodiments.

[0026] Example 1:

[0027] See Figure 3In the case of applying the present invention to a rotary detonation engine, the rotary detonation combustion chamber consists of an outer ring 1 of the combustion chamber, an inner ring 2 of the combustion chamber head, an inner column 6 of the combustion chamber, and an ignition device 7, which together with the nozzle 5 form a rotary detonation engine; in the figure, the head of the piston rod 4 is flush with the inner wall of the outer ring 1 of the combustion chamber. In this state, the present invention will not increase the number of rotary detonation waves.

[0028] Example 2:

[0029] See Figure 4 This is an example of the invention being applied to a rotating detonation engine; in the figure, piston rod 4 is raised, and in this state, the invention can increase the number of rotating detonation waves.

[0030] Example 3:

[0031] See Figure 5 In the case of applying the present invention to a rotating detonation turbine engine, the rotating detonation combustion chamber consists of an outer ring 1 of the combustion chamber, an inner ring 2 of the combustion chamber head, an inner column 6 of the combustion chamber, and an ignition device 7; in the figure, the head of the piston rod 4 is flush with the inner wall of the outer ring 1 of the combustion chamber. In this state, the present invention will not increase the number of rotating detonation waves.

[0032] Example 4:

[0033] See Figure 6 This is an example of the invention being applied to a rotating detonation turbine engine; in the figure, piston rod 4 is raised, and in this state, the invention can increase the number of rotating detonation waves.

Claims

1. A device for increasing the number of rotating detonation waves, comprising a hot spot cavity, a piston rod, and a controller, characterized in that: The hot spot cavity has a hollow cylindrical structure inside, located on the outer wall of the rotating detonation combustor, penetrating the outer wall of the combustor and communicating with the interior of the combustor; the geometric parameters of the hot spot cavity should meet the following conditions: Where d is the diameter of the cylindrical surface inside the hot spot cavity, D is the outer diameter of the rotating detonation combustor, h is the height of the cylindrical surface inside the hot spot cavity, and the axial position of the hot spot cavity on the outer wall of the combustor is close to the head of the combustor; the piston rod is located inside the hot spot cavity, and the piston head is in close contact with the inner surface of the hot spot cavity to form a seal, and can move along the central axis of the cylindrical surface inside the hot spot cavity to change the volume of the hot spot cavity; the controller is fixedly connected to the hot spot cavity and connected to the tail of the piston rod, and is used to control the piston rod to move and change its position to adjust the volume of the hot spot cavity; The aforementioned device for increasing the number of rotating detonation waves is applied to a rotating detonation combustion chamber. It is installed on the outer wall of the rotating detonation combustion chamber and communicates with the interior of the combustion chamber. Under normal conditions, the piston rod head is flush with the inner wall of the outer ring of the combustion chamber, and the volume of the hot spot cavity communicating with the rotating detonation combustion chamber is zero. During operation, the controller raises the piston rod to its highest position, increasing the volume of the hot spot cavity. When the rotating detonation wave propagates inside the combustion chamber and passes through the location of the hot spot cavity, high-temperature combustion products enter the hot spot cavity and remain there. After the rotating detonation wave passes, when the reactants begin to fill axially and reach the location of the hot spot cavity, the combustion products remaining in the hot spot cavity will ignite the reactants prematurely and develop into new rotating detonation waves. After a certain period, these waves coexist stably with the original rotating detonation waves, thereby increasing the number of rotating detonation waves in the combustion chamber.

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