CN117390791A - Design method of expansion type injection structure based on gaseous rotary detonation engine - Google Patents
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Abstract
The invention discloses a design method of an expansion type injection structure based on a gaseous rotary detonation engine, which belongs to the technical field of detonation engines and comprises the following procedures: firstly, determining the size and shape of a casing of a rotary detonation engine, defining pneumatic parameters of engine design points, completing the parameter calculation of the injector according to a proper equivalence ratio, including the injection angle, aperture number and length-diameter ratio of the injector, further completing the parameter calculation of an expansion section of the injector based on the parameters, and finally, respectively determining the expansion angle according to the air/fuel momentum ratio, determining the length of the expansion section according to the flow coefficient, and completing the design of the expansion injection structure based on the gaseous rotary detonation engine. The invention improves the outlet of the injector of the gaseous rotating detonation engine into the expansion type, effectively increases the expansion angle and the distribution area of fuel jet flow, and solves the problem of insufficient circumferential mixing of gaseous fuel.
Description
Technical Field
The invention belongs to the field of detonation engines, and particularly relates to a method for designing an expansion type injection structure of a rotary detonation engine based on a gas state.
Background
In order to meet the design requirements of supersonic cruising and super-maneuverability of the engine in the future, the engine is developing into a novel power system with large thrust-weight ratio, small entropy increase, quick heat release and high thermal efficiency, and the detonation rotary detonation engine is a power system which remarkably improves the propulsion performance of the engine.
Unlike traditional rocket engines and turbojet engines, rotating detonation engines employ a combustion mode in which the leading shock wave is coupled with chemical reaction and there is a strong discontinuity. The propagation speed of the rotating detonation wave formed in this mode can be up to the order of km/s, the gaseous or liquid fuel is rapidly compressed at the wave structure to a high temperature and high pressure state, and then sufficient combustion is achieved, and the mode can maximize the effective work of the engine at a low supercharging ratio. In order to achieve the above-mentioned object, development of a more efficient and stable fuel supply structure is demanded.
Generally, there are two modes of premixed combustion and non-premixed combustion in the rotating detonation engine combustion chamber, but both modes need to ensure sufficient blending of fuel and oxidant to ensure efficient combustion of the rotating detonation waves. The fuel and the oxidant are respectively and independently stored in a non-premixed combustion mode, so that the fuel and the oxidant have better stability and safety, and are the combustion modes mainly adopted in main engineering application. Based on prior studies, it is known that different fuel supplies directly affect the fuel blending characteristics and further affect the detonation combustion performance. At present, the fuel injection structure of the gaseous rotating detonation combustion chamber generally adopts a plurality of small holes for injection, and the structure is simple and mainly comprises a hollow cylindrical rod. The current gaseous fuel injection holes are 0.3-1.5mm in diameter and 1-3mm in length, and the fuel is driven by a certain pressure to cause the gaseous fuel to be injected into the combustion chamber in the form of a jet, but the jet blending effect is poor under the condition, and the expansion angle of the injector outlet jet is generally between 2 degrees and 12 degrees. The existing injection structure has the defects of poor atomization effect and unfavorable spatial distribution of fuel.
Therefore, it is necessary to develop a design method of a gas injection device with simple structure and better mixing effect.
Disclosure of Invention
The invention aims to solve the problems of narrow expansion angle of fuel jet and uneven circumferential mixing of fuel caused by a cylindrical gas jet structure applied to a gaseous rotating detonation engine at present, and provides a design method based on an expansion type jet structure of the gaseous rotating detonation engine.
The technical scheme for realizing the invention is as follows:
the design method of the expansion type injection structure based on the gaseous rotating detonation engine is characterized by comprising the following design flow:
and step 1, determining the size and shape of the rotating detonation engine casing according to the thrust index and the structural constraint.
The rotary detonation engine comprises a rotary air inlet, laval nozzles arranged at the inlet, gas inlets distributed on the inner ring and the outer ring of the annular Laval nozzles, a gas injection structure connected with the gas inlets and the Laval nozzles, a combustion chamber positioned at the outlet of the Laval nozzles, and a combustion chamber outlet positioned at the tail end of the combustion chamber, so as to construct a casing and an engine center inner column of the whole engine.
And 2, calculating injector parameters based on the engine design point pneumatic parameters and the equivalence ratio range.
And 3, determining the injection angle, the aperture, the number of holes and the length-diameter ratio of the fuel injector according to the flow requirement of the injector.
Step 4, designing an injector expansion section structure:
the injector structure parameters comprise an outlet expansion type injection structure, a gas injection structure straight section positioned at the inlet of the expansion type injector, and a gas injection structure expansion section positioned at the outlet of the expansion type injection structure.
Step 5, calculating expansion section parameters of the specific expansion type injection structure:
the expansion section parameters of the open-type injection structure comprise a spray hole aperture D, an expansion angle alpha representing the opening degree of an outlet of the expansion section of the gas injection structure, L1 representing the expansion length of the gas injection structure and L2 representing the length of a straight section of the gas injection structure.
Step 6, calculating the expansion angle of the expansion section of the injector and the length structural parameters of the expansion section:
the expansion angle alpha of the expansion section of the injector is determined based on the momentum ratio of air and gas jet flow, and the length L1 of the expansion section of the gas injection structure, the length L2 of the straight section of the gas injection structure and the aperture D of the jet hole are determined through fuel flow coefficients.
In the process of designing the expansion angle alpha, the expansion angle alpha is determined according to the jet penetration depth and the structural parameters of the expansion section of the Laval nozzle, and is specifically set to be that the gas jet penetration depth is half of the width of the expansion section of the Laval nozzle, wherein the relation between the gas penetration depth and the momentum ratio under a certain gas injection structure is as follows:
wherein: q is the momentum ratio; x is the distance of the particles from the nozzle orifice in the flow direction; y is the penetration depth of the particle perpendicular to the flow direction; d is the orifice diameter of the spray orifice.
The calculation of the momentum ratio is shown as:
wherein: subscripts 1 and 2 represent gas and air, respectively; ρ is the incoming air density in kg/m3; u is the flow direction velocity of the air flow, in m/s.
Air flow velocity u 2 Incoming air speed, gas u 1 The calculation formula of (2) is as follows:
u 1 ＝V 1 cos(α/2)
wherein: v (V) 1 The absolute velocity of the gas jet is alpha, and alpha is the expansion angle of the gas injection structure.
In the process of designing the length L1 of the expansion section, the design that the flow coefficient is not less than 0.85 is ensured, and the flow coefficient calculation formula is as follows:
a is a flow coefficient; q v Volume flow, unit m3/s; d is the diameter of the inner side of the orifice, and the unit is m; l1 is the length of the expansion section; epsilon is the dimensionless flow resistance coefficient; ΔP is the fuel injection pressure difference in MPa.
Compared with the prior art, the invention has the remarkable advantages that:
(1) The expansion type injection structure design method based on the gaseous rotating detonation engine is a novel injection structure design thought suitable for the gaseous fuel rotating detonation engine, and the design of the gaseous injection structure is rapidly completed on the premise of not disturbing the stability of other parts.
(2) According to the expansion type injection structure based on the gaseous rotating detonation engine, provided by the invention, on the premise of not changing the structure of the rotating detonation engine, the mixing effect of fuel gas and incoming air is enhanced by increasing the expansion angle at the outlet of the fuel gas injection structure.
(3) According to the expansion type injection structure design method based on the gaseous rotating detonation engine, the length of the expansion section of the gas injection structure is designed based on the criterion that the flow coefficient is not less than 0.85, so that the flow loss in the fuel injection process is reduced, and the high efficiency and the light weight of an injection system are promoted.
(4) The expansion type injection structure based on the gaseous rotating detonation engine is an independent injection system, does not interfere the operation of other systems, can stably promote the fuel blending characteristic, and improves the detonation performance of the rotating detonation wave.
Drawings
FIG. 1 is a flow chart of a method for designing an expanding type injection structure of an engine based on gaseous rotary detonation
FIG. 2 is a schematic diagram of a gaseous rotating detonation initiation structure as described in the background.
Fig. 3 is a schematic view of a sectional structure in the front view of fig. 2.
Fig. 4 is a schematic cross-sectional view of the upper half of fig. 2.
Fig. 5 is a schematic view of the novel expanding type injection structure to which fig. 2 belongs.
FIG. 6 is a schematic illustration of flow characteristics of an embodiment of the present invention.
Wherein:
1-air inlet, 2-Laval nozzle, 3-gas inlet, 4-gas injection structure, 4.1-gas injection structure straight section, 4.2-gas injection interface expansion section, 5-combustion chamber, 6-combustion chamber outlet, 7-cartridge receiver, 8-engine center inner column.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the invention. All other embodiments, which can be made by one of ordinary skill in the art without creative efforts, are within the scope of the present invention based on the embodiments of the present invention.
It should be noted that all directional indicators (such as up, down, left, right, front, and rear … …) in the embodiments of the present invention are merely used to explain the relative positional relationship, movement, etc. between the components in a particular posture (as shown in the drawings), and if the particular posture is changed, the directional indicator is changed accordingly.
Furthermore, descriptions such as those referred to as "first," "second," and the like, are provided for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implying an order of magnitude of the indicated technical features in the present disclosure. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.
In the present invention, unless specifically stated and limited otherwise, the terms "connected," "affixed," and the like are to be construed broadly, and for example, "affixed" may be a fixed connection, a removable connection, or an integral body; the "connection" may be mechanical or electrical. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
In addition, the technical solutions of the embodiments of the present invention may be combined with each other, but it is necessary to base that the technical solutions can be implemented by those skilled in the art, and when the technical solutions are contradictory or cannot be implemented, the combination of the technical solutions should be considered to be absent, and not included in the scope of protection claimed in the present invention.
The following describes the specific embodiments, technical difficulties and inventions of the present invention in further detail in connection with the present design examples.
Referring to fig. 1 to 6, a design method of an expansion type injection structure based on a gaseous rotating detonation engine comprises the following steps:
step 1, determining the size and shape of a rotating detonation engine casing according to thrust indexes and structural constraints:
the rotary detonation engine comprises a rotary air inlet 1, laval nozzles 2 arranged at the inlet, gas inlets 3 distributed on the inner ring and the outer ring of the annular Laval nozzles 2, a gas injection structure 4 connected with the gas inlets 3 and the Laval nozzles 2, a combustion chamber 5 positioned at the outlet of the Laval nozzles, a combustion chamber outlet 6 positioned at the tail end of the combustion chamber 5, and a casing 7 and an engine center inner column 8 of the whole engine.
The air inlet 1 is a part for connecting high-pressure air with the Laval nozzle 2; the Laval nozzle 2 is designed into a two-dimensional annular channel and comprises a contraction section, a throat and an expansion section, and is arranged between the air inlet 1 and the combustion chamber 5, so that high-pressure air forms supersonic air flow; the gas injection structures 4 are respectively arranged at the expanding sections of the inner ring and the outer ring of the Laval nozzle 2, so that the mixing effect of fuel and air is promoted; the combustion chamber 5 is an annular channel with a straight or expanding angle smaller than 7 degrees and is arranged at the outlet of the expanding section at the downstream of the Laval nozzle 2; the combustion chamber outlet 6 is located at the rear end of the combustion chamber 5, from which the combusted gases are ejected into the atmosphere.
The incoming air pressure at the inlet of the combustion chamber is greater than 3.0MPa.
Step 2, calculating injector parameters based on the pneumatic parameters of the engine design points and the equivalent ratio range;
and 3, determining the injection angle, the aperture, the number of holes and the length-diameter ratio of the fuel injector according to the flow requirement of the injector.
Step 4, designing an injector expansion section structure:
the injector structure parameters comprise an outlet expansion type injection structure 4, a gas injection structure straight section 4.1 positioned at the inlet of the expansion type injector 4 and a gas injection structure expansion section 4.2 positioned at the outlet of the expansion type injection structure 4.
Step 5, calculating the expansion section parameters of the expansion type injection structure:
the expansion section parameters of the open-type injection structure comprise a spray hole aperture D, a divergence angle alpha representing the opening degree of an outlet of the expansion section 4.2 of the gas injection structure, L1 representing the length of the expansion section 4.2 of the gas injection structure and L2 representing the length of the straight section 4.1 of the gas injection structure.
Step 6, calculating the expansion angle of the expansion section of the injector and the length structural parameters of the expansion section:
the expansion angle alpha of the injector expansion section is determined based on the momentum ratio of air and gas jet flow, and the length L1 of the gas injection structure expansion section 4.2, the length L2 of the gas injection structure straight section 4.1 and the orifice aperture D are determined through the fuel flow coefficient.
In the process of designing the expansion angle alpha, the expansion angle alpha is determined according to the jet penetration depth and the structural parameters of the expansion section of the Laval nozzle 2, and is specifically set to be that the gas jet penetration depth is half of the width of the expansion section of the Laval nozzle 2, wherein the relation between the gas penetration depth and the momentum ratio under a certain gas injection structure is as follows:
wherein: q is the momentum ratio; x is the distance of the particles from the nozzle orifice in the flow direction; y is the penetration depth of the particle perpendicular to the flow direction; d is the orifice diameter of the spray orifice.
The calculation of the momentum ratio is shown as:
wherein: subscripts 1 and 2 represent gas and air, respectively; ρ is the incoming air density in kg/m3; u is the flow direction velocity of the air flow, in m/s.
Air flow velocity u 2 Incoming air speed, gas u 1 The calculation formula of (2) is as follows:
u 1 ＝V 1 cos(α/2)
wherein: v (V) 1 The absolute velocity of the gas jet, α, is the divergence angle of the gas injection structure 4.
In the process of designing the length L1 of the expansion section, the design that the flow coefficient is not less than 0.85 is ensured, and the flow coefficient calculation formula is as follows:
a is a flow coefficient; q v Is the volume flow, unit m 3 S; d is the aperture of the spray hole, and the unit is m; l1 is the length of the expansion section; epsilon is the dimensionless flow resistance coefficient; ΔP is the fuel injection pressure difference in MPa.
The contraction section of the Laval nozzle adopts a hyperbolic curve to design the contraction section, and the method is as follows:
wherein x is m Is the axial position of the front and rear connecting points of the two curves, h 1 For the inlet section of the contraction section to be half-height, h 2 The throat section of the contraction section is half-height, h is half-height of the section x at the axial position, L is the length of the contraction section, and x is taken m L=0.45 to 0.6, and is appropriately lengthened so as to leave a certain installation margin.
The expansion section of the Laval nozzle is designed by adopting a characteristic line method, and the Mach number of the outlet of the expansion section is ensured to be between 1.5 and 2.8.
The fuel injection structures are uniformly distributed on the expansion section of the Laval nozzle, the outer ring and the inner ring are in one-to-one correspondence, the included angle between the injection jet and the air is set to be 45-90 degrees, the number of injection holes is 40-120, the aperture parameter range is 0.3-2.0 mm, the included angle between two adjacent injection structures is 2-5 degrees, and the length-diameter ratio is 2-30.
The fuel injection structure 4 is a plurality of hollow cylinders or rectangular columns, the channel is divided into a straight section 4.1 and an expanding section 4.2 from front to back, and a spreading angle is arranged at the outlet of the expanding section, so that the outlet of the injection interface presents a conical structure with a certain spreading angle.
The expansion angle of the expansion section of the fuel injection structure is set between 60 degrees and 120 degrees, the length of the expansion section is set between 1mm and 3mm, so that the jet angle of high-pressure fuel passing through the expansion section is larger than 15 degrees, the mixing of fuel and air is enhanced, and the rotating detonation combustion is further promoted.
Example 1
Referring to fig. 1 to 6, the method for designing the expansion type injection structure based on the gaseous rotating detonation engine comprises the following steps:
and step 1, determining that the rotating detonation engine casing is in a circular shape according to the thrust index and the structural constraint, wherein the size is phi 130mm (diameter) multiplied by 150mm (length).
And 2, the range of aerodynamic parameters and equivalence ratio is 0.6-1.2 based on the design point of the engine.
And 3, determining that the injection angle of the fuel injector 4 is 90 degrees, the aperture is 0.8mm, the number of holes is 60 pairs and the length-diameter ratio is 4.0 according to the flow requirement of the injector.
And 4, designing an expansion section structure of the injector, wherein the structure of the gas injector is that an inlet section is a straight section, and an outlet section is an expansion section.
And 5, calculating parameters of an expansion section of the definite expansion type injection structure, and designing according to 200g/s of incoming air, 1.0 equivalent ratio, 0.9 flow coefficient and 5mm of expansion section width of the Laval nozzle 2.
And 6, determining the expansion angle of the expansion section of the injector and the length structural parameters of the expansion section, wherein the expansion angle of the expansion section 4.2 of the gas injection structure is 15 degrees, the length of the expansion section is 2mm, the length of the straight section 4.1 of the gas injection structure is 4mm, and the diameter of the hole is 0.8mm.
The invention is based on a conventional rotary detonation engine main body, and comprises an air inlet 1 connected with incoming air, high-pressure air flows into a Laval nozzle 2 from the air inlet 1 to form supersonic air flow with Mach number between 1.5 and 2.8, fuel gas enters the Laval nozzle 2 from a fuel gas inlet 3 through a fuel gas injection structure 4, the fuel gas and the air are fully mixed into a combustion chamber 5, detonation and detonation combustion are carried out in the combustion chamber 5, finally, the fuel gas enters the atmosphere through a combustion chamber outlet 6, and the engine completes work. It should be noted that the case 7 needs to be designed with heat protection in mind, and the engine center post 8 is used for disposing the engine fuel system and the electromechanical system, which is not considered to be in the scope of the present invention.
It is important to note that the fuel injection structure is connected with the fuel inlet 3 of high-pressure fuel gas and the incoming air of the Laval nozzle 2, and the nozzle of the fuel injection structure is composed of a straight section 4.1 parallel to the fuel flow direction and an expanding section 4.2 of a conical structure with a certain angle with the straight section. When the gas enters the gas injection structure 4, the gas first enters the straight section 4.1 of the gas injection structure, which is identical to the conventional injection structure, where the high-pressure gas forms a high-speed jet; the high velocity jet then enters the expansion section 4.2 of the gas injection structure where the gas jet expands for the first time and then enters the expansion section of the laval nozzle 2 to achieve adequate mixing of fuel and air. It has been found that air eddies are generated near the walls of the conical diverging section when the high pressure fuel jet separates from the walls, which air eddies interact with the fuel jet to form a fuel-air shear layer that enhances mass transport between the fuel and air, further promoting the blending effect between the fuel and the incoming air. Therefore, compared with the original injection interface, the expansion type injection structure based on the gaseous rotating detonation engine is more beneficial to realizing expansion of fuel jet flow and mixing with air, so that the mixing effect of fuel and air is improved, and detonation and propagation of rotating detonation waves are promoted.
Claims (8)
1. The design method of the expansion type injection structure based on the gaseous rotary detonation engine is characterized by comprising the following steps:
step 1, determining the size and shape of a rotating detonation engine casing according to thrust indexes and structural constraints:
the rotary detonation engine comprises a rotary air inlet (1), laval nozzles (2) arranged at the inlet, gas inlets (3) distributed on the inner ring and the outer ring of the annular Laval nozzles (2), a gas injection structure (4) connected with the gas inlets (3) and the Laval nozzles (2), a combustion chamber (5) positioned at the outlet of the Laval nozzles, a combustion chamber outlet (6) positioned at the tail end of the combustion chamber (5), and a casing (7) and an engine center inner column (8) of the whole engine are constructed;
step 2, calculating injector parameters based on the pneumatic parameters of the engine design points and the equivalent ratio range;
step 3, determining the injection angle, the aperture, the number of holes and the length-diameter ratio of the fuel injector according to the flow requirement of the injector;
step 4, designing an injector expansion section structure:
the injector structure parameters comprise an outlet expansion type injection structure (4), a gas injection structure straight section (4.1) positioned at the inlet of the expansion type injector (4), and a gas injection structure expansion section (4.2) positioned at the outlet of the expansion type injection structure (4);
step 5, calculating the expansion section parameters of the expansion type injection structure:
the expansion section parameters of the open-type injection structure comprise a spray hole aperture D, a expansion angle alpha representing the opening degree of an outlet of the expansion section (4.2) of the gas injection structure, L1 representing the length of the expansion section (4.2) of the gas injection structure and L2 representing the length of a straight section (4.1) of the gas injection structure;
step 6, calculating the expansion angle of the expansion section of the injector and the length structural parameters of the expansion section:
the expansion angle alpha of the expansion section of the injector is determined based on the momentum ratio of air and gas jet flow, and the length L1 of the expansion section (4.2) of the gas jet structure, the length L2 of the straight section (4.1) of the gas jet structure and the orifice aperture D are determined by the fuel flow coefficient;
in the process of designing the expansion angle alpha, the expansion angle alpha is determined according to the jet penetration depth and the structural parameters of the expansion section of the Laval nozzle (2), and is specifically set to be that the gas jet penetration depth is half of the width of the expansion section of the Laval nozzle (2), wherein the relation between the gas penetration depth and the momentum ratio under a certain gas injection structure is as follows:
wherein: q is the momentum ratio; x is the distance of the particles from the nozzle orifice in the flow direction; y is the penetration depth of the particle perpendicular to the flow direction; d is the aperture of the spray hole;
the calculation of the momentum ratio is shown as:
wherein: subscripts 1 and 2 represent gas and air, respectively; ρ is the incoming air density in kg/m3; u is the airflow direction speed, and the unit is m/s;
air flow velocity u 2 Incoming air speed, gas u 1 The calculation formula of (2) is as follows:
u 1 ＝V 1 cos(α/2)
wherein: v (V) 1 Alpha is the expansion angle of the gas injection structure (4) and is the absolute speed of the gas jet;
in the process of designing the length L1 of the expansion section, the design that the flow coefficient is not less than 0.85 is ensured, and the flow coefficient calculation formula is as follows:
a is a flow coefficient; q v Is the volume flow, unit m 3 S; d is the aperture of the spray hole, and the unit is m; l1 is the length of the expansion section; epsilon is the dimensionless flow resistance coefficient; ΔP is the fuel injection pressure difference in MPa.
2. The method for designing an expanding injection structure based on a gaseous rotating detonation engine according to claim 1, wherein the method comprises the following steps: the air inlet (1) is a part for connecting high-pressure air with the Laval nozzle (2); the Laval nozzle (2) is designed into a two-dimensional annular channel and comprises a contraction section, a throat and an expansion section, and is arranged between the air inlet (1) and the combustion chamber (5) so that high-pressure air forms supersonic air flow; the gas injection structures (4) are respectively arranged at the expanding sections of the inner ring and the outer ring of the Laval nozzle (2) to promote the mixing effect of fuel and air; the combustion chamber (5) is an annular channel with a straight or expanding angle smaller than 7 degrees and is arranged at the outlet of an expanding section at the downstream of the Laval nozzle (2); the combustion chamber outlet (6) is positioned at the tail end of the combustion chamber (5), and the burnt gas is sprayed into the atmosphere.
3. The method for designing an expanding injection structure based on a gaseous rotating detonation engine as claimed in claim 1, wherein: the incoming air pressure at the inlet of the combustion chamber is greater than 3.0MPa.
4. The method for designing an expanding injection structure based on a gaseous rotating detonation engine as claimed in claim 1, wherein: the contraction section of the Laval nozzle adopts a hyperbolic curve to design the contraction section, and the method is as follows:
wherein x is m Is the axial position of the front and rear connecting points of the two curves, h 1 For the inlet section of the contraction section to be half-height, h 2 The throat section of the contraction section is half-height, h is half-height of the section x at the axial position, L is the length of the contraction section, and x is taken m L=0.45 to 0.6, and is appropriately lengthened so as to leave a certain installation margin.
5. The method for designing a gaseous rotating detonation engine-based expanding injection structure of claim 1, wherein: the expansion section of the Laval nozzle is designed by adopting a characteristic line method, and the Mach number of the outlet of the expansion section is ensured to be between 1.5 and 2.8.
6. The method for designing an expanding injection structure based on a gaseous rotating detonation engine as claimed in claim 1, wherein: the fuel injection structures are uniformly distributed on the expansion section of the Laval nozzle, the outer ring and the inner ring are in one-to-one correspondence, the included angle between the injection jet and the air is set to be 45-90 degrees, the number of injection holes is 40-120, the aperture parameter range is 0.3-2.0 mm, the included angle between two adjacent injection structures is 2-5 degrees, and the length-diameter ratio is 2-30.
7. The method for designing an expanding injection structure based on a gaseous rotating detonation engine as recited in claim 6, wherein: the fuel injection structure (4) is a plurality of hollow cylinders or rectangular columns, the channel is divided into a straight section (4.1) and an expanding section (4.2) from front to back, and an expanding angle is arranged at the outlet of the expanding section, so that the outlet of the injection interface presents a conical structure with a certain expanding angle.
8. The method for designing an expanding injection structure based on a gaseous rotating detonation engine of claim 7, wherein: the expansion angle of the expansion section of the fuel injection structure is set between 60 degrees and 120 degrees, the length of the expansion section is set between 1mm and 3mm, so that the jet angle of high-pressure fuel passing through the expansion section is larger than 15 degrees, the mixing of fuel and air is enhanced, and the rotating detonation combustion is further promoted.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311515277.3A CN117390791A (en) | 2023-11-15 | 2023-11-15 | Design method of expansion type injection structure based on gaseous rotary detonation engine |
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