阅读说明：本技术 用于吸气式旋转爆震燃烧室的前传激波抑制结构 (Forward shock wave suppression structure for air-breathing rotary detonation combustion chamber ) 是由 应卓君 张义宁 孟皓 马虎 于 2021-01-05 设计创作，主要内容包括：本发明公开了一种用于吸气式旋转爆震燃烧室的前传激波抑制结构,包括用于压缩空气进入的隔离段右端、用于前传激波进入的隔离段左端、设置在隔离段左端和隔离段右端的等直段；所述等直段设有激波陷阱腔,所述激波陷阱腔将等直段分割为内层和外层,内层和外层之间用于前传激波在其中来回反射衰减并消失；所述等直段沿轴向均匀设置有多组环形槽,每组环形槽由多个弧形槽组成；本发明可实现旋转爆震燃烧室与进气道和压气机的匹配与稳定工作。(The invention discloses a front-propagation shock wave suppression structure for an air-breathing rotary detonation combustor, which comprises an isolation section right end for compressed air to enter, an isolation section left end for front-propagation shock wave to enter, and equal straight sections arranged at the isolation section left end and the isolation section right end; the equal straight section is provided with a shock wave trap cavity, the shock wave trap cavity divides the equal straight section into an inner layer and an outer layer, and a forward-propagating shock wave between the inner layer and the outer layer is reflected back and forth in the inner layer and attenuated and disappears; a plurality of groups of annular grooves are uniformly arranged in the equal straight section along the axial direction, and each group of annular grooves consists of a plurality of arc-shaped grooves; the invention can realize the matching and stable work of the rotary detonation combustor, the air inlet channel and the air compressor.)

1. A front propagation shock wave suppression structure for an air-breathing rotary detonation combustor is characterized by comprising an isolation section right end (3) for compressed air to enter, an isolation section left end (1) for front propagation shock wave to enter, and a shock wave trap cavity (4) arranged between the isolation section left end (1) and the isolation section right end (3); the equal straight section (2) is provided with a shock wave trap cavity (4), the shock wave trap cavity (4) divides the equal straight section (2) into an inner layer (2-1) and an outer layer (2-2), and a forward propagating shock wave between the inner layer (2-1) and the outer layer (2-2) is reflected back and forth to attenuate and disappear; the equal straight section (2) is evenly provided with a plurality of groups of annular grooves along the axial direction, and each group of annular grooves consists of a plurality of arc-shaped grooves.

2. The structure of claim 1, wherein n is the number of groups of annular grooves (5) that satisfy n.gtoreq.2.

3. The front-propagation shock wave suppression structure as recited in claim 1, wherein the number m of the arc-shaped grooves satisfies m ≧ 2.

4. The structure of claim 1, wherein the compressed air and the forward shock wave respectively enter the equal straight section (2) from the right end (3) and the left end (1) of the isolation section, and the respective flow processes are as follows: compressed air enters the equal straight section (2) from the right end (3) of the isolation section and flows out from the left end (1) of the isolation section to enter the combustion chamber; the induced forward shock wave of the rotating detonation wave enters the inner layer (2-1) of the equal straight section (2) from the left end (1) of the isolation section, wherein part of the shock wave enters the shock wave trap cavity (4) through the annular groove (5), and disappears after being reflected and attenuated back and forth between the outer wall surface of the inner layer (2-1) and the inner wall surface of the outer layer (2-2).

Technical Field

The invention belongs to the field of design of an isolation section of an air-breathing rotary detonation engine, and particularly relates to a front-propagation shock wave suppression structure for an air-breathing rotary detonation combustion chamber.

Background

The knocking combustion is combustion in a near constant volume condition, theoretically has a higher thermal cycle efficiency than the constant pressure combustion, and has a self-supercharging capability and a lower specific fuel consumption rate. The rotary detonation combustion chamber is a combustion chamber based on continuous detonation combustion, reactants are filled in the combustion chamber, energy release is completed after one or more detonation waves which are continuously and rotationally propagated along the circumferential direction are combusted, and formed high-temperature and high-pressure combustion products are discharged through an outlet.

The rotary detonation combustor is applied to an air-breathing engine by utilizing the advantages of the rotary detonation combustor, and a main combustion chamber of a stamping or turbine engine is replaced by the rotary detonation combustor, so that the heat efficiency can be improved, the pressure increasing ratio can be improved, the load of an air compressor can be reduced, the number of stages of the air compressor can be reduced, the volume and the weight of the combustion chamber can be reduced, the heat protection area can be reduced, the transition from constant-pressure combustion to constant-volume combustion of the air-breathing engine can be hopefully realized, and the rotary detonation combustor becomes the preferred scheme of the next-.

Because the rotary detonation wave can form a front-propagation oblique shock wave which moves along with the detonation wave at the upstream of the combustion chamber when propagating in the combustion chamber, the oblique shock wave is not beneficial to the normal work of the gas compressor, the working efficiency of the gas compressor can be reduced, and in severe cases, surging can be even caused, so that expensive engines and test equipment are damaged. Because the traditional isolation section is mostly a simple equal straight and flat structure at present, the inhibition effect of the front propagation strong shock wave aiming at the rotary detonation wave is limited, and the shock wave cannot be sufficiently attenuated before entering an air inlet channel or an air compressor, if the shock wave works for a long time, the normal work of an engine is influenced, and the service life of the engine is shortened.

Disclosure of Invention

The invention aims to provide a front-propagation shock wave suppression structure for an air-breathing rotary detonation combustor, which is used for suppressing pressure disturbance transmitted upstream in the rotary detonation combustor and enabling shock waves to be attenuated and disappear before entering an air inlet or an air compressor.

The technical solution for realizing the purpose of the invention is as follows:

a front propagation shock wave suppression structure for an air-breathing rotary detonation combustor comprises an isolation section right end for compressed air to enter, an isolation section left end for front propagation shock wave to enter, and an equal straight section arranged between the isolation section left end and the isolation section right end; the equal straight section is provided with a shock wave trap cavity, the shock wave trap cavity divides the equal straight section into an inner layer and an outer layer, and a front propagation shock wave is reflected and attenuated back and forth between the inner layer and the outer layer; the equal straight section is evenly provided with a plurality of groups of annular grooves along the axial direction, and each group of annular grooves consists of a plurality of arc-shaped grooves.

Compared with the prior art, the invention has the following remarkable advantages:

the shock wave trap structure can be applied between an air inlet channel of a ramjet engine and a rotary detonation combustor or between a gas turbine engine gas compressor and the rotary detonation combustor, and can continuously attenuate shock waves induced by the shock waves in the rotary detonation combustor, inhibit pressure disturbance of the rotary detonation combustor from forwarding, prevent the air inlet channel from being not started and the gas compressor from working abnormally and surging, and realize matching and stable working of the rotary detonation combustor, the air inlet channel and the gas compressor.

Drawings

FIG. 1 is an isometric view of a forward shock suppression structure of an air breathing rotary detonation combustor of the present invention.

FIG. 2 is a cross-sectional view of a forward shock suppression structure of the air breathing rotary detonation combustor of the present invention.

FIG. 3 is a simulation result diagram of the inner and outer wall surfaces of the front shock suppression structure of the air-breathing rotary knocking combustor.

FIG. 4 is a graph showing the simulation result of the inner wall surface of the outer layer of the front shock wave suppression structure of the air-breathing rotary knocking combustor.

Detailed Description

The invention is further described with reference to the following figures and embodiments.

With reference to fig. 1 and 2, the front propagation shock wave suppression structure for the air-breathing rotary detonation combustor comprises an isolation section right end 3 for compressed air to enter, an isolation section left end 1 for front propagation shock wave to enter, and an equal straight section 2 arranged between the isolation section left end 1 and the isolation section right end 3; the equal straight section 2 is provided with a shock wave trap cavity 4, and the shock wave trap cavity 4 divides the equal straight section 2 into an inner layer 2-1 and an outer layer 2-2; a plurality of groups of annular grooves are uniformly arranged in the equal straight section 2 along the axial direction; the number n of groups of the annular grooves 5 meets the condition that n is more than or equal to 2; each group of annular grooves consists of a plurality of arc-shaped grooves which are uniformly arranged along the circumferential direction of the equal straight section 2 at intervals, and the number m of the arc-shaped grooves in a single annular groove 5 meets the requirement that m is more than or equal to 2; the values of n and m and the size of the slot are determined according to specific conditions.

As shown in FIG. 2, compressed air and a front shock wave respectively enter the equal straight section 2 from the right end 3 and the left end 1 of the isolation section.

The flow process of the compressed air is as follows:

compressed air enters the equal straight section 2 from the right end 3 of the isolation section along the path 2 and flows out from the left end 1 of the isolation section to enter the combustion chamber.

The propagation process of the front propagation laser wave is as follows:

the induced forward-propagating shock wave of the rotating detonation wave enters the inner layer 2-1 of the equal straight section 2 from the path 1 through the left end 1 of the isolation section, wherein part of the shock wave enters the shock wave trap cavity 4 through the annular groove 5 in a way similar to the path 3, and disappears after being reflected and attenuated back and forth between the outer wall surface of the inner layer 2-1 and the inner wall surface of the outer layer 2-2.

As shown in fig. 3 and 4, according to the propagation process of the induced shock wave of the rotating detonation wave in the outer wall surface of the inner layer 2-1 and the inner wall surface of the outer layer 2-2 obtained from the simulation result, it can be seen that the intensity of the shock wave propagated in the shock wave trap cavity 4 is sufficiently attenuated before entering the right end 3 of the isolation section, and the peak pressure (about 0.85MPa) when the shock wave propagated in the shock wave trap cavity 4 enters the left end 1 of the isolation section is reduced to be close to the pressure of the right end 3 of the isolation section where the compressed air enters, which indicates that the induced shock wave of the rotating detonation wave basically disappears in the shock wave trap cavity.

The shock wave trap structure can be applied between an air inlet channel of a ramjet engine and a rotary detonation combustor or between a gas turbine engine gas compressor and the rotary detonation combustor, and can continuously attenuate shock waves induced by the shock waves in the rotary detonation combustor, inhibit pressure disturbance of the rotary detonation combustor from forwarding, prevent the air inlet channel from being not started and the gas compressor from working abnormally and surging, and realize matching and stable working of the rotary detonation combustor, the air inlet channel and the gas compressor.