A rotating detonation engine combustion chamber and method of using the same

Abstract

This patent discloses a rotating detonation engine combustion chamber and a method of using the same, which adopts a structure in which multiple annular combustion chambers are nested from the inside to the outside, thereby improving the thrust of the engine; since the rotation directions of the rotating detonations of two adjacent annular cavities are opposite, the torque caused by the rotation of the working medium is offset, making the engine power output more stable and controllable; inlet and outlet air channels are arranged on the inner and outer walls of each annular combustion chamber, and the combustion chamber is cooled by fuel; in addition, the use of coaxial shearing and orthogonal collision combined nozzles can effectively improve the atomization effect and quickly form an explosive mixture.

Description

Technical Field

[0001] This patent relates to the field of combustion testing of aviation engine components, and specifically to a rotating detonation engine combustion chamber and a method of using the same. Background Art

[0002] Detonation combustion is essentially a complex process that achieves extremely fast chemical reactions with low entropy increase. The extremely fast reaction rate makes detonation combustion close to an isochoric process. Compared with isobaric combustion, its thermodynamic cycle efficiency is more than 20% higher, which will greatly reduce the fuel consumption rate of the propulsion system. In addition, detonation combustion is a form of self-pressurization combustion, so it can reduce the number of compressor stages, reduce turbine load, and even completely eliminate the complex supercharging system, thereby simplifying the engine structure. For this reason, detonation combustion technology may bring about disruptive innovations in the field of propulsion, is a research hotspot for the world's military powers, and is the next technological commanding heights that major powers are competing for.

[0003] Rotating Detonation Engine (RDE), also called Continuous Detonation Engine (CDE), refers to an engine that uses a rotating detonation combustion mode. In a rotating detonation engine, the detonation wave propagates continuously in the annular rotating detonation combustion chamber (RDC). Therefore, the rotating detonation engine theoretically only needs one ignition and detonation. The detonation wave propagates continuously in the annular combustion chamber and continuously generates thrust. Since the rotating detonation engine does not require components such as a head rotary valve to control the process of pulse injection of propellant, and can adjust parameters such as the number of wave heads to adapt to the incoming flow conditions, it can work in both air-breathing and rocket modes. In recent years, it has attracted widespread attention from researchers around the world and is the most popular detonation engine in the world.

[0004] The concept of rotating detonation combustion was first proposed in 1960 by Voitsekhovskii and others from the Lavrentiev Institute of Fluid Mechanics in the Soviet Union. They first realized the rotating detonation of premixed acetylene / oxygen on a disc-shaped test device. At the beginning of this century, with the demand for the application of high-speed aircraft, rotating detonation engines have once again become a research hotspot. As the research gradually deepens, rotating detonation engines are increasingly favored by people. At present, the United States, Russia, China, Japan, Poland, France and other countries are actively conducting research on rotating detonation engines.

[0005] The most common combustion chamber design of the rotating detonation engine is a coaxial annular cavity structure, such as Figure 1As shown, on the injection surface, fuel and oxidant are sprayed into the annular combustion chamber through fine slits or circular holes, and a detonation wave is formed after ignition, and a single-head or multi-head detonation wave rotating circumferentially is developed in the combustion chamber. The reactants are consumed on the detonation wave surface, and the high-temperature and high-pressure combustion gas after combustion is expanded and rapidly ejected almost along the circular axis direction to generate thrust. However, the combustion chamber of the rotary detonation engine of the prior art has the following disadvantages:

[0006] 1. The gas flow rate formed by a single annular combustion chamber is small, resulting in low thrust;

[0007] 2. A single annular combustion chamber will inevitably generate rotational torque, which brings inconvenience to the application of weapons and equipment. If it is to be used on an aircraft, the rotational torque must be eliminated;

[0008] 3. Wall cooling problem. If the temperature of the combustion chamber wall is too high, the mixed gas will easily self-ignite. Spontaneous combustion will lead to deflagration combustion instead of knock combustion. Therefore, if the wall cooling problem is not in place, it is easy to deflagration, and there will be no knock combustion;

[0009] 4. The coaxial nozzle atomizes more evenly, but the droplets exist for a long time; the collision nozzle is conducive to atomization, but the uniformity is poor. The combination of coaxial shearing and orthogonal collision nozzles can improve the atomization effect, shorten the atomization time, and quickly form a combustible mixed gas. Summary of the invention

[0010] This patent aims to propose a rotating detonation engine combustion chamber and its use method; it can solve the shortcomings of the prior art, such as low thrust, inability to eliminate rotational torque, low wall cooling efficiency, and unsatisfactory nozzle ineffectiveness.

[0011] To achieve the above purpose, this patent adopts the following technical solutions:

[0012] A rotating detonation engine combustion chamber is composed of multiple layers of annular tube cavities nested inside and outside, each annular tube cavity forms an independent rotating detonation engine combustion chamber, and compared with every two adjacent cavities, the rotation directions of the rotating detonations of the two cavities are opposite.

[0013] Furthermore, the number of the rotating detonation engine combustion chambers is an even number.

[0014] Furthermore, there are a total of 4 externally nested multi-layer annular tube cavities, and the cavities are the 1st to 4th layers from the inside to the outside. In the 1st and 2nd layer cavities, the rotation directions of the two rotating detonations are opposite; in the 2nd and 3rd layer cavities, the rotation directions of the two rotating detonations are opposite; in the 2nd and 3rd layer cavities, the rotation directions of the two rotating detonations are opposite.

[0015] Furthermore, each layer of the combustion chamber in the shape of an annular tube cavity has a plurality of cooling holes distributed along the circumference of the cavity.

[0016] Furthermore, fuel is introduced into each cooling hole, and the fuel is used to cool the combustion chamber wall.

[0017] Furthermore, the cooling holes are arranged in pairs, and a pair of cooling holes respectively includes a cooling medium inlet and a cooling medium outlet.

[0018] Furthermore, each layer of the combustion chamber in the shape of an annular tube cavity has a plurality of propellant nozzles distributed along the circumference of the cavity.

[0019] Furthermore, the propellant nozzle adopts a coaxial shearing type and an orthogonal collision type combined nozzle.

[0020] A method for using the rotating detonation engine combustion chamber according to the above structure makes the rotating directions of the rotating detonations of every two adjacent cavities opposite.

[0021] Furthermore, there are a total of 4 externally nested multi-layer annular tube cavities, and the cavities are the 1st to 4th layers from the inside to the outside. In the 1st and 2nd layer cavities, the rotation directions of the two rotating detonations are opposite; in the 2nd and 3rd layer cavities, the rotation directions of the two rotating detonations are opposite; in the 2nd and 3rd layer cavities, the rotation directions of the two rotating detonations are opposite.

[0022] Furthermore, the number of the annular cavities is determined according to the thrust required in actual working conditions.

[0023] Furthermore, the number of the annular cavities is determined according to the propellant flow rate required in actual working conditions.

[0024] The rotary detonation engine combustion chamber of this patent adopts a structure in which multiple annular combustion chambers are nested from the inside to the outside, which effectively increases the intake flow rate and thus increases the thrust of the engine; since the rotation directions of the rotary detonations of two adjacent annular cavities are opposite, the torque caused by the rotation of the working medium is offset, making the engine power output more stable and controllable; inlet and outlet channels are set on the inner and outer walls of each annular combustion chamber, and the combustion chamber is cooled by fuel; in addition, the use of coaxial shear type and orthogonal collision type combined nozzles can effectively improve the atomization effect and quickly form an explosive mixture. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Attached Figure 1 It is a schematic diagram of the structure of the combustion chamber of the rotating detonation engine in the prior art;

[0026] Attached Figure 2 A schematic diagram of the structure of the combustion chamber of the rotating detonation engine;

[0027] Attached Figure 3 A schematic diagram of the rotation direction of the rotating detonation in each annular tube cavity of the rotating detonation engine combustion chamber of the present invention;

[0028] Attached Figure 4 A schematic diagram of cooling channels on the outer wall of each annular tube cavity of the rotating detonation engine combustion chamber of the present invention;

[0029] Attached Figure 5 It is a cross-sectional view of the cooling passages on the outer wall of each annular tube cavity of the combustion chamber of the rotating detonation engine of the present invention;

[0030] Attached Figure 6 This is a structural diagram of the propellant nozzle of the rotating detonation engine combustion chamber of the present invention.

[0031] Description of reference numerals:

[0032] 1-coolant outlet, 2-coolant inlet, 3-fuel nozzle, 4-fuel nozzle passage 1, 5-fuel nozzle passage 2, 6-fuel nozzle passage 3, 7-oxidant nozzle passage. DETAILED DESCRIPTION

[0033] In order to make the above-mentioned purposes, features and advantages of this patent more obvious and easy to understand, the specific embodiments of this patent are described in detail below in conjunction with the accompanying drawings.

[0034] like Figure 2 As shown, the present patent provides a rotary detonation engine combustion chamber, which is composed of a plurality of annular tube cavities nested inside and outside, and each annular tube cavity forms an independent rotary detonation engine combustion chamber. When working, fuel and oxidant are sprayed into the annular cavity combustion chamber through a nozzle, and a detonation wave is formed after ignition, which can develop a circumferentially rotating single-head or multi-head detonation wave in the combustion chamber, and the reactants are consumed on the detonation wave surface. The high-temperature and high-pressure combustion gas after combustion is expanded and rapidly ejected almost along the circular axis direction to generate thrust; in the present patent, an independent circumferentially rotating single-head or multi-head detonation wave is formed in each annular tube cavity, and each generates engine thrust independently; therefore, the thrust of the rotary detonation engine combustion chamber should be the sum of the thrusts generated independently by each combustion chamber; it can be seen that the technical solution of the present patent constructs multiple independent combustion chambers in the form of a plurality of multi-layer annular tube cavities. Compared with the traditional "parallel" combustion chamber, the present patent is obviously more compact in structure, and has better overall strength and aerodynamic shape.

[0035] In this embodiment, Figure 3As shown, there are a total of 4 externally nested multi-layer annular tube cavities, and the cavities are 1-4 layers from the inside to the outside, wherein the rotation direction of the rotary detonation in the 1st layer cavity is clockwise, the rotation direction of the rotary detonation in the 2nd layer cavity is counterclockwise, the rotation direction of the rotary detonation in the 3rd layer cavity is clockwise, and the rotation direction of the rotary detonation in the 4th layer cavity is counterclockwise; since the rotation directions of the rotary detonations in the 1st and 2nd layer cavities are opposite, the torque generated by the rotary detonation wave in the 1st layer cavity is opposite to that in the 2nd layer cavity; similarly, the torque generated by the rotary detonation wave in the 3rd layer cavity is opposite to that in the 4th layer cavity; thus, the torques generated by the rotary detonation in the 1st and 2nd layers cancel each other out; and the torques generated by the rotary detonation in the 3rd and 4th layers cancel each other out; thus, the rotary detonation engine combustion chamber of this patent, as a whole, exhibits a relatively small total torque to the outside, thereby reducing the torque added to the aircraft by the rotary detonation engine as a whole to a minimum, and ultimately making the aircraft easier to control.

[0036] Furthermore, the torque of the first cavity can be made exactly equal to the torque of the second cavity by adjusting parameters such as the mass of the working medium in the first and second cavities, the speed of the rotating detonation, etc., so that the two can completely offset each other; similarly, the torque generated by the rotating detonation in the third and fourth cavities can also completely offset each other; in this case, the torque displayed by the rotating detonation engine combustion chamber as a whole is zero, that is, it only provides axial thrust.

[0037] In this embodiment, Figure 3-5 As shown, each layer of the combustion chamber in the shape of an annular tube cavity has a plurality of cooling holes 1 and 2 distributed along the circumference of the cavity, wherein cooling hole 1 represents the coolant outlet and cooling hole 2 represents the coolant inlet; each pair of coolant outlet 1 and coolant inlet 2 mutually constitute a coolant loop, thereby cooling the wall surface of the combustion chamber in the shape of annular tube cavity; a plurality of pairs of coolant loops are evenly distributed on the wall surface of the combustion chamber in the shape of annular tube cavity, thereby cooling the wall surface at a high speed and evenly, thereby avoiding the disadvantage that the mixed gas is easy to spontaneously ignite due to the excessive temperature of the combustion chamber wall surface.

[0038] Furthermore, in this embodiment, fuel is introduced into each cooling hole and the fuel is used to cool the combustion chamber wall. In this way, on the one hand, liquid fuel is used to cool the detonation combustion chamber wall to avoid deflagration combustion in the detonation combustion chamber. On the other hand, the fuel can be preheated to reduce viscosity and improve atomization and combustion efficiency.

[0039] In this embodiment, Figure 6As shown, the propellant nozzle adopts a coaxial shear type and orthogonal collision type combined nozzle, wherein 4 and 5 are two independent fuel nozzle passages, and the fuel sprayed by the two are collided and atomized in the front; 6 is the fuel nozzle channel and 7 is the oxidizer nozzle channel. The speed difference between the nozzles 6 and 7 is large, and atomization is performed through the shear effect at the outlet. The propellant nozzle of this patent adopts a coaxial shear type and orthogonal collision type combined nozzle, so that the fuel after shear atomization is further collided and atomized, which greatly improves the atomization effect and improves the combustion efficiency.

[0040] This patent also relates to a method for using a rotating detonation engine combustion chamber, in which the rotation directions of the rotating detonations of every two adjacent cavities are opposite. The method for controlling the rotation direction of the rotating detonation in the combustion chamber is already a prior art and will not be repeated here. In this method, for example, there are a total of 4 externally nested multi-layer annular tube cavities, and the cavities are 1st to 4th layers from the inside to the outside. The rotation direction of the rotating detonation in the 1st layer of cavity is controlled to be clockwise, the rotation direction of the rotating detonation in the 2nd layer of cavity is counterclockwise, the rotation direction of the rotating detonation in the 3rd layer of cavity is clockwise, and the rotation direction of the rotating detonation in the 4th layer of cavity is counterclockwise. Please refer to the principle described above for details. After adopting this control method, the torque generated by the rotating detonation engine itself can be greatly reduced, thereby making its power output more stable and controllable.

[0041] Although the patent is disclosed as above, the patent is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the patent. Therefore, the protection scope of the patent shall be based on the scope defined by the claims.

Claims

1. A rotating detonation engine combustion chamber, characterized in that: The combustion chamber is composed of multiple layers of annular tube cavities nested inside and outside, each annular tube cavity forms an independent rotating detonation engine combustion chamber, and the rotation directions of the rotating detonations of each two adjacent cavities are opposite; Each layer of the combustion chamber in the shape of an annular tube cavity has a plurality of cooling holes distributed along the circumference of the cavity. Fuel is introduced into each cooling hole to cool the combustion chamber wall. The cooling holes are arranged in pairs, and a pair of cooling holes respectively includes a cooling medium inlet and a cooling medium outlet. Multiple pairs of coolant circuits are evenly distributed on the combustion chamber wall in the shape of an annular tube cavity, so as to avoid the disadvantage that the mixed gas is easy to spontaneously ignite due to the excessive temperature of the combustion chamber wall. Each layer of the combustion chamber in the shape of an annular tube cavity has a plurality of propellant nozzles distributed along the circumference of the cavity. The propellant nozzle is a combination of a coaxial shearing type and an orthogonal collision type nozzle. In the coaxial shearing type nozzle, the inner layer is an oxidant nozzle channel, and the outer layer is a fuel nozzle channel. The speed difference between the two nozzles is large, and atomization is performed at the outlet through the shear effect; the orthogonal collision type nozzle is two independent fuel nozzle passages, and the fuel ejected from the two is atomized by collision in the front; the coaxial shearing type and orthogonal collision type combination nozzle allows the fuel after shear atomization to be further atomized by collision.

2. The rotating detonation engine combustion chamber according to claim 1, characterized in that: The number of the rotating detonation engine combustion chambers is an even number.

3. The rotating detonation engine combustion chamber according to claim 2, characterized in that: There are a total of 4 nested multi-layer annular tube cavities, and the cavities are the 1st to 4th layers from the inside to the outside. In the 1st and 2nd layer cavities, the rotation directions of the two rotating detonations are opposite; in the 2nd and 3rd layer cavities, the rotation directions of the two rotating detonations are opposite.

4. A method for using a rotating detonation engine combustion chamber according to any one of claims 1 to 3, characterized in that: The rotation directions of the rotating detonations of every two adjacent cavities are opposite.

5. The method for using the rotating detonation engine combustion chamber according to claim 4, characterized in that: There are 4 multi-layer annular tube cavities nested outside, and the cavities are 1st to 4th layers from the inside to the outside. In the 1st and 2nd layers of cavities, the rotation directions of the two rotating detonations are opposite; in the 2nd and 3rd layers of cavities, the rotation directions of the two rotating detonations are opposite.

6. The method for using the rotating detonation engine combustion chamber according to claim 5, characterized in that: The number of annular cavities is determined according to the thrust required in actual working conditions.

7. The method for using the rotating detonation engine combustion chamber according to claim 5, characterized in that: The number of annular cavities is determined according to the propellant flow rate required in actual working conditions.

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