CN-117418965-B - Oblique detonation engine and detonation method thereof

CN117418965BCN 117418965 BCN117418965 BCN 117418965BCN-117418965-B

Abstract

The invention discloses an oblique detonation engine and a detonation method thereof, wherein the oblique detonation engine comprises a fairing, a flame-retardant fuel injector, a flammable fuel injector, an air inlet channel, a combustion chamber and a tail nozzle, the air inlet channel comprises a first wedge surface and a second wedge surface, the flame-retardant fuel injector is arranged on an upper wall surface close to an outlet of the air inlet channel, the combustion chamber is communicated with the air inlet channel, a tail wedge surface is arranged at the tail end of the combustion chamber, the wedge surface angle of the tail wedge surface is 20 degrees, the tail nozzle is communicated with the combustion chamber, the flammable fuel injector is arranged at the front end of the fairing, and the adopted double-layer fuel auxiliary detonation method utilizes flammable fuel to assist the flame-retardant fuel to detonate, so that the length of a flame-retardant fuel induction area is reduced, no dynamic structural response and extra energy injection are facilitated for engineering model machine application, thrust gain is obtained to the greatest extent, and the flight number lower limit of the oblique detonation engine can be greatly widened due to the characteristic that flame-retardant gas is not easy to detonate.

Inventors

TENG HONGHUI
ZHANG PENGFEI
NIU SHUZHEN
YANG PENGFEI
DU WENQIANG
LIU SHUAI
LIU SIYUAN

Assignees

北京理工大学

Dates

Publication Date: 20260512
Application Date: 20231017

Claims (5)

1. An oblique detonation engine is characterized by comprising a fairing, a flame-retardant fuel injector, a flammable fuel injector, an air inlet channel, a combustion chamber and a tail nozzle; the air inlet channel comprises a first wedge surface and a second wedge surface, and hypersonic speed flows through the first wedge surface and the second wedge surface to be compressed to generate oblique shock waves; The fire-resistant fuel injector is arranged on the upper wall surface close to the outlet of the air inlet channel and is used for injecting fire-resistant fuel when hypersonic incoming flow enters the air inlet channel; the combustion chamber is communicated with the air inlet channel, the mixture of fuel and hypersonic incoming flow is fully combusted through the combustion chamber, the tail end of the combustion chamber is provided with a tail wedge surface, and the wedge surface angle of the tail wedge surface is 20 degrees; The tail spray pipe is communicated with the combustion chamber and is used for discharging combustion products of the combustion chamber so as to generate driving force; The combustible fuel injector is configured at the front end of the fairing and is used for injecting the combustible fuel when hypersonic incoming flow enters the air inlet passage, and the combustible fuel injector is a transverse array cantilever type injector.
2. A detonation method of a diagonal detonation engine for detonation of the diagonal detonation engine of claim 1, comprising: hypersonic incoming flow enters the air inlet channel and is compressed on the first wedge surface and the second wedge surface, and meanwhile, a flame-retardant fuel injector injects flame-retardant fuel and a flammable fuel injector injects flammable fuel; The hypersonic incoming flow after compression is mixed with the flame retardant fuel injected by the flame retardant fuel injector and the flammable fuel injected by the flammable fuel injector to obtain mixed incoming flow; the mixed incoming flow is configured to comprise mixed upper-layer sub-incoming flows and lower-layer sub-incoming flows, wherein the upper-layer sub-incoming flows are mixtures of flame-retardant fuel and upper-layer gas which are positioned on the upper layer of the inlet of the combustion chamber, and the upper-layer gas is air; And compressing the upper sub-incoming flow and the lower sub-incoming flow on the tail wedge surface, so that the upper sub-incoming flow and the lower sub-incoming flow are finally combusted in a knocking mode.
3. The method of detonating a diagonal detonation engine of claim 2, wherein the flame retardant fuel comprises a hydrocarbon fuel.
4. The method for detonating a oblique detonation engine according to claim 3, wherein the hydrocarbon fuel includes any one or a combination of several of ethylene, methane and kerosene.
5. The detonation method of a diagonal detonation engine as claimed in claim 2, wherein the combustible fuel is hydrogen.

Description

Oblique detonation engine and detonation method thereof Technical Field The invention relates to the technical field of air suction type hypersonic propulsion, in particular to an oblique detonation engine and a detonation method thereof. Background Hypersonic propulsion technology is one of the important technologies of aerospace concern in the 21 st century. At present, the performance development of the traditional aero-engine gradually reaches a limit, and the thrust requirement of higher supersonic speed cannot be continuously met. The existing aero-engine is based on constant pressure combustion, and the combustion organization form is one of reasons that the engine performance is difficult to continue to be improved. Accordingly, researchers have desired to meet higher thrust demands with knock combustion that approximates constant volume combustion, and have proposed three solutions, pulse knock engine (PDE), rotary knock engine (RDE), and oblique knock engine (ODE). Among them, the Oblique Detonation Engine (ODE) has been receiving more and more attention in recent years because of its simple structure, small size of combustion chamber, and higher than impulse, by utilizing Oblique Detonation Wave (ODW) to burn the structure. Since the concept of oblique detonation propulsion was proposed, researchers have conducted a lot of researches on oblique detonation waves in high-speed incoming flows, focusing on the detonation, the stationarity and the composition of wave system structures of the oblique detonation waves in an oblique detonation combustion chamber, and mainly relating to the wave system structures of oblique detonation regions and the combustion tissues of wave surfaces of the oblique detonation waves. One of the key points in the study of the detonation wave system structure of the detonation zone is the length of the induction zone, hydrogen (hydrogen) is used as fuel, the oblique detonation wave structures under different flight conditions are simulated numerically, the length of the detonation wave induction zone is greatly increased along with the increase of the flight height and the decrease of the flight Mach number, however, the detonation wave cannot be detonated within a limited length due to the overlong induction zone, and thus the thrust cannot be generated. Therefore, it is needed to propose a detonation engine and a detonation method thereof to reduce the detonation wave induction zone length. Patent document 1 (bulletin number: CN 114109649B) provides a super-high speed ramjet engine, the engine body comprises an air inlet channel, a mixing section, a combustion chamber and a tail nozzle which are connected in sequence, a first wedge surface unit is arranged on the air inlet channel, a second wedge surface unit is arranged on the mixing section, a combustion chamber wedge surface for inducing a resident oblique detonation wave is arranged on the combustion chamber, a tail nozzle wedge surface is arranged on the tail nozzle, a jet orifice unit for jetting propellant spray is arranged on the second wedge surface unit, the edge of the air inlet channel and the edge of the mixing section are non-horizontal straight lines, and the problems of high resistance of a fuel injector, limited fuel injection height, low fuel mixing efficiency, poor combustion stability, serious detonation wave/boundary layer interference and the like are solved by improving the engine structure in patent document 1, however, the structure still cannot reduce the length of the detonation induction area, cannot detonate within a limited length, and thus cannot generate thrust waves. Patent document 2 (bulletin number: CN 116291880A) provides a method for realizing the acceleration detonation of a detonation engine by disturbing a detonation zone, which adds external disturbance on the lower wall surface of a combustion chamber of the detonation engine, so that incoming gas is influenced by external disturbance to generate a bow shock wave in the detonation zone of the detonation wave, the bow shock wave generated by disturbing the detonation zone interacts with the skew shock wave generated at the front end of the lower wall surface of the combustion chamber of the engine to generate a detonation wave, however, the method still cannot reduce the length of a detonation wave induction zone, and the detonation wave cannot detonate within a limited length, so that thrust cannot be generated. Disclosure of Invention In view of the above, the present invention provides a detonation engine and a detonation method thereof, so as to reduce the length of the detonation wave induction zone. In a first aspect, the present application provides a diagonal detonation engine comprising a cowling, a refractory fuel injector, a combustible fuel injector, an intake duct, a combustion chamber, and a tail pipe; the air inlet channel comprises a first wedge surface and a second wedge surface, and hypersonic speed flows throug