Hypersonic speed air inlet channel based on leading edge shock wave adjustment and fuel pre-injection regulation and control method

Abstract

The invention belongs to the field of aerospace engines, and discloses a hypersonic air inlet channel based on leading edge shock wave adjustment and fuel pre-injection regulation and control and a control method. The air inlet channel comprises a lip cover, an inner wall face, a front body compression face and a high-pressure fuel cavity. The lip cover and the inner wall surface of the air inlet channel jointly define an inner channel of the air inlet channel; the front body compression face is connected to the position extending forwards from the inner wall face of the air inlet channel. An adjustable wedge block fuel injection structure is rotationally arranged at the front edge of the front body compression surface, and wall surface fuel injection holes are formed in the surface side by side; the high-pressure fuel cavity comprises a first high-pressure fuel cavity and a second high-pressure fuel cavity; a fuel channel is formed in the adjustable wedge fuel injection structure, one end of the fuel channel communicates with the first high-pressure fuel cavity, and an opening of the other end of the fuel channel faces the air channel inner channel. Through a local mechanical adjustment mode of the adjustable wedge block fuel injection structure and integrated design and cooperative control of fuel pre-injection pneumatic adjustment and control on an air inlet channel compression surface, air inlet channel shock wave adjustment and fuel pre-injection mixing are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field related to aerospace engines, and more specifically, relates to a hypersonic inlet and a control method based on leading edge shock wave regulation and fuel pre-injection control. Background Art

[0002] In the future, horizontal take-off and landing reusable space shuttles must be able to operate in a wide range of speeds and airspaces, from zero speed to hypersonic speed, near ground space, and even near-Earth orbit. They must have the characteristics of cruise economy and acceleration capability, excellent specific impulse and thrust-to-weight ratio, compact structure, and suitable for reusability. Traditional single-type power such as turbines, ramjets, and rockets cannot meet the requirements, and air-breathing combination engines are an inevitable trend. Among them, ramjets have become an indispensable part of the combination engine due to their good performance in the hypersonic stage.

[0003] Generally, the flight speed of ramjet engine is above Mach 3, which realizes gas supercharging based on the principle of supersonic airflow shock wave compression, and organizes combustion on this basis, and finally forms high-temperature gas that expands through the tail nozzle to generate thrust. At present, the scramjet engine in the medium-speed range of flight Mach number 3 to 7 has made comprehensive breakthroughs and entered the engineering application stage. However, with the increase of flight Mach number, ramjet engine will face problems such as extremely high enthalpy and high-speed flow environment, efficient fuel injection mixing and combustion organization under extremely short residence time conditions, extremely increased wall friction and increased thermal protection costs. At present, aerodynamic adjustment (plasma injection, fuel pre-injection, etc.) or combustion enhancement technology has been applied to the development of hypersonic propulsion technology with higher Mach numbers such as Mach number 10, which has alleviated the above problems to a certain extent, but problems such as integrated performance improvement and expansion of air-breathing working boundaries still need to be solved.

[0004] Theoretically, air-breathing hypersonic propulsion systems can work effectively in the range of Mach numbers 3 to 15 and altitudes of 0 to 40 km. As higher Mach number propulsion systems with flight Mach numbers above Mach 7 enter the scope of theoretical research, a variety of new combustion modes (shock wave induced combustion, detonation combustion) have been proposed one after another. The fundamental purpose is to achieve high Mach number working capability and optimize propulsion performance output through integrated matching optimization of internal flow and combustion organization. Regardless of supersonic combustion, shock wave induced combustion or oblique detonation combustion, the basic premise is that fuel injection and mixing meet the requirements of efficient combustion organization, among which the fuel injection group mode and premixing requirements will depend on the engine internal flow conditions and specific combustion organization mode. Under high Mach number hypersonic flight conditions, the internal flow velocity is extremely high and the residence time is extremely short. It is extremely difficult to achieve short-distance, fast and efficient fuel mixing combustion organization in limited space and extreme time. This is one of the technical factors that restrict the upper limit of the working speed range of air-breathing engines.

[0005] How to expand the working boundaries of high Mach number propulsion systems and then utilize more efficient combustion modes such as the above-mentioned new combustion organizations has become an urgent problem to be solved in hypersonic propulsion systems. Summary of the invention

[0006] In view of the above defects or improvement needs of the prior art, the present invention provides a hypersonic inlet and control method based on leading edge shock wave regulation and fuel pre-injection regulation, which aims to achieve precise inlet shock wave regulation and fuel pre-injection mixing effect at the same time through the local mechanical adjustment method of the adjustable wedge fuel injection structure at the leading edge of the inlet, and the integrated design and coordinated control of the aerodynamic regulation of the fuel pre-injection on the inlet compression surface, thereby solving the practical difficulties faced in the high-efficiency flow organization in a wide speed range and the high-efficiency combustion organization in multi-mode in hypersonic propulsion systems.

[0007] To achieve the above-mentioned object, according to one aspect of the present invention, an air intake duct based on leading edge shock wave regulation and fuel pre-injection regulation is provided, comprising: a lip cover, an air intake duct inner wall surface, a front body compression surface and a high-pressure fuel chamber;

[0008] The lip mask is located on the inner wall surface of the air inlet duct, and together with the inner wall surface of the air inlet duct, forms an inner channel of the air inlet duct;

[0009] The front compression surface is connected to the portion extending forward from the inner wall of the air inlet duct; an adjustable wedge fuel injection structure is rotatably provided at the front edge of the front compression surface, and wall fuel injection holes are arranged side by side on the front compression surface;

[0010] The high-pressure fuel chamber includes a first high-pressure fuel chamber and a second high-pressure fuel chamber; the first high-pressure fuel chamber is connected to the adjustable wedge fuel injection structure, and the second high-pressure fuel chamber is connected to the wall fuel injection hole; a fuel channel is provided inside the adjustable wedge fuel injection structure;

[0011] A fuel channel is provided inside the adjustable wedge fuel injection structure, one end of the fuel channel is connected to the first high-pressure fuel cavity, and the other end of the fuel channel opens toward the channel inside the intake duct.

[0012] As a preferred embodiment of the present invention, the end of the adjustable wedge fuel injection structure facing the inner channel of the air intake duct is provided with an outwardly extending cantilever beam, and an opening at one end of the fuel channel is arranged on the outwardly extending cantilever beam facing the inner channel of the air intake duct.

[0013] As a preferred embodiment of the present invention, a rotating shaft is further provided at the front edge of the front compression surface, and is rotatably connected to the adjustable wedge fuel injection structure via the rotating shaft.

[0014] As a preferred embodiment of the present invention, the adjustable wedge fuel injection structure is flush with the front body compression surface when it is not lifted, and the contact surface with the inner part of the air inlet duct entity is an arc surface.

[0015] As a preferred embodiment of the present invention, the adjustable wedge fuel injection structure has a lifting angle ranging from 0° to 10° relative to the prerequisite compression surface.

[0016] As a preferred embodiment of the present invention, when hydrogen fuel is used, the diameter of the wall fuel injection hole is 1-2 mm, and when kerosene fuel is used, the diameter of the wall fuel injection hole is 0.3-0.5 mm.

[0017] As a preferred embodiment of the present invention, the front body compression surface sequentially includes a first-stage compression surface, a second-stage compression surface and a third-stage compression surface extending in the direction of the inner channel of the inlet duct; the front end of the second-stage compression surface forms a turning point with the first-stage compression surface, the front end of the front end of the third-stage compression surface forms a turning point with the second-stage compression surface, and the rear end of the third-stage compression surface is connected to the inner wall surface of the inlet duct; the first-stage compression surface is divided into a front section and a rear section at the rear end of the adjustable wedge block fuel injection structure, the front section is the upper surface of the adjustable wedge block fuel injection structure, when the adjustable wedge block fuel injection structure is in a closed state, the front section and the rear section are collinear, and when the adjustable wedge block fuel injection structure is in a raised state, the front section and the rear section form an angle equal to the rotation angle of the adjustable wedge block fuel injection structure.

[0018] According to another aspect of the present invention, a control method for an intake duct based on leading edge shock wave regulation and fuel pre-injection control is provided, comprising the following steps:

[0019] S1: After obtaining the flight status, the engine integrated control system determines the required working mode of the air inlet and instructs the air inlet to perform preliminary angle adjustment on the adjustable wedge fuel injection structure; wherein, when the air inlet is in a sub-rated or rated working state, the working mode of the adjustable wedge fuel injection structure is controlled to be closed; when the air inlet is in an over-rated working state, the preliminary lifting angle of the adjustable wedge fuel injection structure is determined according to the compression wave system regulation requirement;

[0020] S2: Determine the final lifting angle of the adjustable wedge fuel injection structure and the overall injection strategy of the wall fuel injection hole according to the requirements of the downstream combustion organization for fuel mixing efficiency.

[0021] As a preferred embodiment of the present invention, after completing the preliminary angle adjustment of the adjustable wedge fuel injection structure, it also includes adjusting the overall injection strategy by combining the requirements of the downstream combustion organization for fuel mixing efficiency with the local wall drag reduction and thermal protection requirements.

[0022] As a preferred embodiment of the present invention, the engine integrated control system obtains the incoming flow parameters in real time, and adjusts the initial lift angle of the adjustable wedge fuel injection structure in real time according to the intake duct performance requirements and the current intake duct performance parameters.

[0023] In general, the above technical solution conceived by the present invention has the following technical advantages compared with the prior art:

[0024] (1) When the adjustable wedge fuel injection structure of the present invention cooperates with the fuel jet, due to the rotatable structural design, it can be finely adjusted in the direction of the channel in the inlet duct, and can play a role in regulating the compression wave system in the over-rated stage of the inlet duct. According to the target flight speed range requirements, the engine inlet duct is designed based on the low Mach number design point, so as to improve the flow capture efficiency of the inlet duct in a wide speed range, expand the upper limit of the working Mach number of the inlet duct, effectively shorten the length of the inlet duct, and reduce the wall friction resistance and thermal protection cost; at the same time, the fuel pre-injection action performed by the adjustable wedge and the wall nozzle can effectively improve the fuel premixing efficiency, provide convenience for the downstream combustion organization, reduce the fuel mixing distance requirements of the combustion chamber, and effectively shorten the structural length of the combustion chamber, thereby reducing the inflow wall resistance and thermal protection cost of the combustion chamber.

[0025] (2) The present invention preferably has an adjustable wedge fuel injection structure with an adjustable wedge with a cantilever beam injection structure, and the outwardly extended cantilever beam is used for fuel injection, the purpose of which is to achieve downstream injection of fuel, increase penetration depth, and avoid fuel accumulation in the downstream reflow area of ​​the wedge to produce local intense combustion.

[0026] (3) When the inlet of the present invention is applied, by fully combining the reliability of the mechanical structure and the advantages of the inlet fuel pre-injection technology, and equipped with a control method with a real-time feedback mechanism, the upper limit of the working Mach number of the traditional inlet can be expanded. Thus, a new design idea based on the low Mach number design point / weak compression aerodynamic surface is formed, and the requirements of the higher Mach number speed domain are met through the lower Mach number design point inlet, and the beneficial effects of enhancing the fuel premixing efficiency, shortening the engine size, reducing the wall friction resistance and thermal protection cost are simultaneously achieved, thereby achieving the purpose of improving the overall performance of the propulsion system and expanding the upper limit of the working boundary.

[0027] The fuel pre-injection strategy includes the following: the present invention adjusts the fuel pre-injection strategy in real time according to the working state of the engine intake duct. When the intake duct is in a sub-rated (rated) working state, the fuel pre-injection strategy is injected through the adjustable wedge block close to the compression wall surface in the intake duct to achieve fuel pre-mixing while avoiding the decrease of the intake duct flow capture capacity; when the intake duct is in an over-rated working state, the fuel pre-mixing is achieved through the adjustable wedge block at the front edge of the front compression surface, which can achieve compression wave system regulation and reduce the flow distortion of the intake duct outlet. This ensures that the intake duct can work normally in a wider speed range.

[0028] (4) The near-wall fuel jet forms a cooling film effect on the front outer compression surface, reducing the thermal protection cost. The oil-gas mixture can form boundary layer combustion after shock wave ignition, which has the effect of reducing wall friction drag. Therefore, the regulation of the wedge injection structure can be combined with the wall fuel injection as an active cooling and drag reduction measure for flexible use.

[0029] (5) The present invention proposes a new type of high Mach number inlet that integrates leading edge shock wave regulation and fuel pre-injection and a control method thereof, which is suitable for a flight Mach number range of 7-15+, and can be used in an air-breathing hypersonic propulsion system. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of an intake duct with an adjustable wedge fuel injection structure according to an example of the present invention;

[0031] Figure 2 A fuel pre-injection control method based on an intake port with an adjustable wedge fuel injection structure according to an example of the present invention;

[0032] Figure 3 Design point inlets for existing different Mach numbers; Figure 3 (a) The inlet is designed at Ma 8, and (b) The inlet is designed at Ma 15.

[0033] Figure 4 Schematic diagram of the intake duct based on the Ma=8 design point according to the present invention; Figure 4 (a) is a cross-sectional view of the air intake duct, and (b) is a top view of the air intake duct;

[0034] Figure 5 It is a partial enlarged schematic diagram of the adjustable wedge fuel injection structure of the present invention; Figure 5 (a) is a diagram of the adjustable wedge fuel injection structure in a lifted state, and (b) is a diagram of the adjustable fuel injection structure in a closed state;

[0035] Figure 6 A schematic diagram of a calculation model for adjusting the angle of an adjustable wedge fuel injection structure according to an example of the present invention;

[0036] Figure 7 A typical dual intake port over-rated working state of the intake port exemplified by the present invention;

[0037] Figure 8 This is a schematic diagram of the compression wave system adjustment of the intake duct under the overrated working state according to the example of the present invention.

[0038] Throughout the drawings, the same reference numerals are used to denote the same structures, wherein:

[0039] 1-lip cover, 2-inner wall of the air inlet, 3-forebody compression surface, 4-adjustable wedge fuel injection structure, 5-high pressure fuel cavity, 6-wall fuel spray hole, 7-inner channel of the air inlet. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0041] The invention provides an air intake duct with integrated leading edge shock wave regulation and fuel pre-injection.

[0042] like Figure 1 As shown, an air intake duct with integrated leading edge shock wave regulation and fuel pre-injection includes: an air intake duct inner wall surface 2, a lip cover 1 located on the air intake duct inner wall surface 2, and the air intake duct inner wall surface 2 and the lip cover 1 together form an air intake duct inner channel 7; a forebody compression surface 3 extending forward from the air intake duct inner wall surface 2, an adjustable wedge fuel injection structure 4 rotatably arranged at the leading edge of the forebody compression surface 3, and wall fuel spray holes 6 arranged side by side on the forebody compression surface 3; the high-pressure fuel cavity includes a first high-pressure fuel cavity connected to the adjustable wedge fuel injection structure 4, and a second high-pressure fuel cavity correspondingly connected to the wall fuel spray holes 6; wherein, a fuel channel connected to the first high-pressure fuel cavity is arranged inside the adjustable wedge fuel injection structure 4, and the opening of one end of the fuel channel faces the air intake duct inner channel 7.

[0043] In some embodiments, an end of the adjustable wedge fuel injection structure 4 facing the inlet channel 7 is provided with an outrigger cantilever beam, and an opening at one end of the fuel channel is provided on the outrigger cantilever beam, facing the inlet channel 7. The outrigger cantilever beam is used for fuel injection, the purpose of which is to increase the fuel penetration depth and prevent the fuel from gathering in the reflow area downstream of the wedge, resulting in local intense combustion. The length L of the cantilever beam is determined by the size of the reflow area during the design stage.

[0044] In some embodiments, the adjustable wedge fuel injection structure 4 is disposed at the leading edge of the forebody compression surface 3, and the lifting angle δ0 can be adjusted by a rotating shaft disposed inside the leading edge of the forebody compression surface 3, and the rotating shaft is driven by a motor and a corresponding mechanical structure.

[0045] Furthermore, the adjustable wedge fuel injection structure 4 is as wide as the inner wall surface 2 of the air inlet passage.

[0046] Furthermore, when the adjustable wedge fuel injection structure 4 is in the open state, the range of the lifting angle relative to the front body compression surface 3 is generally less than 10°.

[0047] Furthermore, when the adjustable wedge fuel injection structure 4 is in the closed state, the upper surface is flush with the front body compression surface 3, and the surface in contact with the internal entity of the air inlet is an arc surface, ensuring that the sealing is maintained during the adjustment process.

[0048] In some embodiments, the size of the wall fuel injection hole is related to the type of fuel used. When hydrogen fuel is used, the diameter of the wall fuel injection hole 6 is 1-2 mm. When kerosene fuel is used, the diameter of the wall fuel injection hole 6 is 0.3-0.5 mm.

[0049] In some embodiments, the front body compression surface 3 includes a first-stage compression surface, a second-stage compression surface and a third-stage compression surface extending backward in sequence, the front end of the second-stage compression surface forms a turning point with the first-stage compression surface, the front end of the third-stage compression surface is similar, and the rear end is connected to the inner wall of the inlet duct; the first-stage compression surface is divided into a front section and a rear section at the rear end of the adjustable wedge fuel injection structure, the front section is the upper surface of the adjustable wedge fuel injection structure, when the adjustable wedge fuel injection structure is in a closed state, the front section and the rear section are collinear, when the adjustable wedge fuel injection structure is in an open state, the front section and the rear section form an angle, which is equal to the rotation angle of the adjustable wedge fuel injection structure.

[0050] It should be noted that the forebody compression surface is generally designed with a compression wave system according to the equal shock wave intensity criterion, and then the coordinate values ​​of the key points of the outer compression surface are calculated based on the geometric relationship.

[0051] Therefore, when the above-mentioned inlet is used in an air-breathing propulsion system, the first compression wave will be generated at the front edge of the forebody compression surface under supersonic incoming flow conditions, and the subsequent extended compression surface will generate different compression wave systems depending on the type of inlet. Generally speaking, when the inlet is in the rated working state, the compression wave system will converge at the inlet lip. The position of the adjustable wedge fuel injection structure 4 at the front edge of the forebody compression surface 3 is relatively fixed. When the inlet is in the over-rated working state, the lifting angle of the adjustable wedge fuel injection structure 4 is adjusted by the rotating shaft to achieve shock wave control. The wall fuel nozzle 6 can be flexibly designed and configured according to the specific configuration and size of the inlet. Then, based on the structural design of the adjustable wedge fuel injection structure 4 and combined with the design of the specific configuration and size of the inlet, the requirements of shock wave control and fuel premixing can be met.

[0052] The present invention provides a control method for an intake duct based on any of the aforementioned leading edge shock wave regulation and fuel pre-injection regulation. The intake duct is connected to an engine integrated control system based on motor control (specifically: an adjustable wedge fuel injection structure 4 is connected to the engine integrated control system through a rotating control motor and a high-pressure fuel chamber through an electromagnetic valve). The working state of the adjustable wedge fuel injection structure 4 is determined according to the current working state and demand of the intake duct, and combined with Figure 2The fuel pre-injection control method of the intake port based on the adjustable wedge fuel injection structure is described in detail, and the specific examples are as follows:

[0053] S1: After obtaining the flight status, the engine integrated control system determines the required working mode of the air inlet and instructs the air inlet to complete the structural adjustment; the structural adjustment is to adjust the angle of the adjustable wedge fuel injection structure, as follows:

[0054] By determining that when the designed air intake is in a sub-rated or rated working state, the working mode of the adjustable wedge fuel injection structure is controlled to be closed, and when the designed air intake is in an over-rated working state, the working mode of the adjustable wedge fuel injection structure is controlled to be open, and the lifting angle of the adjustable wedge fuel injection structure is calculated according to the compression wave system control requirements; wherein, the lifting angle δ0 is preliminarily determined by the shock wave relationship, specifically: given the wavefront airflow parameters, assuming the initial value of the deflection angle δ, the x value is obtained according to the wavefront parameters, thereby obtaining the wavefront and waveback density ratio ρ2 / ρ1 and the y value, and the wavefront and waveback static pressure ratio is calculated by the formula:

[0055]

[0056] in Where γ1 and γ2 are the specific heat ratios before and after the wave, β is the shock wave compression angle, ρ1 and ρ2 are the gas densities before and after the wave, Ma 1n ,Ma 2n is the Mach number before and after the wave;

[0057] The ratio of static temperature and static pressure before and after the wave is derived as follows:

[0058]

[0059] Based on the energy conservation formula, it is determined whether the energy conservation is satisfied after adopting the given initial value δ of the deflection angle. If not, the deflection angle δ is continuously updated for the next iteration until the accuracy requirement is met.

[0060]

[0061] The initial lifting angle δ0 of the adjustable wedge fuel injection structure is calculated by δ0=δ-δ1, where δ1 is the current lifting angle of the wedge.

[0062] S2: After preliminarily determining the lifting angle of the adjustable wedge fuel injection structure, determine the final lifting angle of the adjustable wedge fuel injection structure and the overall injection strategy of the wall fuel injection hole based on the requirements of the downstream combustion organization for fuel mixing efficiency.

[0063] Among them, the combustion organization is generally measured by the combustion efficiency η along the way. com Characterizes, and its fuel mixing efficiency η mixThe relationship is as follows:

[0064] η com =f(η mix ,Ma,T,σ,x)(6);

[0065] Where Ma, T, σ respectively correspond to the Mach number, temperature, and total pressure recovery coefficient at the inlet port outlet; x is the distance along the flow path. Specifically, the final lifting angle of the adjustable wedge fuel injection structure and the overall injection strategy of the wall fuel injection hole can be determined through numerical simulation calculation and analysis of the entire flow channel of the engine.

[0066] In some embodiments, after preliminarily determining the lifting angle of the adjustable wedge fuel injection structure, it also includes adjusting the overall injection strategy by combining the requirements of the downstream combustion organization for fuel mixing efficiency with the local wall drag reduction and thermal protection requirements.

[0067] In some embodiments, changes in incoming flow parameters (including flight Mach number, altitude, angle of attack, etc.) are fed back to the engine integrated control system in real time, and the output signal of the rotary motor is adjusted in real time according to the inlet performance requirements and the current inlet performance parameters to control the lifting angle of the adjustable wedge fuel injection structure; the engine combustion chamber performance parameter monitoring results are fed back to the engine integrated control system in real time, and the high-pressure fuel chamber is controlled by the solenoid valve to control fuel delivery, and the fuel injection structure and the wall fuel nozzle are used to perform fuel injection mixing.

[0068] In order to make the purpose, technical solutions and advantages of this patent more clear, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0069] In order to facilitate the description of the advantages of the structure of the present invention, the traditional air inlet design is adopted as follows: Two Mach numbers (Ma=8 and Ma=15) are selected as the benchmark design conditions, and the equal shock wave intensity method is used to design the binary air inlet.

[0070] That is, given the initial value of the first deflection angle δ1, based on the variable specific heat single-channel oblique shock wave calculation, the first oblique shock wave angle θ1 and the corresponding airflow parameters behind the wave are obtained. Based on the equal shock wave intensity method, the second oblique shock wave angle θ2 and the corresponding airflow parameters behind the wave are calculated from the first oblique shock wave angle θ1. Similarly, the third oblique shock wave angle θ2 and the corresponding airflow parameters behind the wave can also be obtained.

[0071] M0sinθ1=M1sinθ2=M2sinθ3(7);

[0072] At this time, according to the second and third shock wave angles and the wave front and wave rear parameters, the second and third deflection angles δ2 and δ3 can be obtained. Based on the given total deflection angle δ of the inlet duct, the first deflection angle δ1 of the next iteration is updated, and the above calculations are repeated to repeatedly update the three deflection angles δ1, δ2 and δ3 until the accuracy requirements are met. After determining the first three deflection angles δ1, δ2 and δ3, for the fourth and fifth deflection angles δ4 and δ5, based on the given total deflection angle δ and the outer cover inclination angle θ, the following is derived according to the geometric relationship:

[0073] δ=δ1+δ2+δ3

[0074] δ4=δ-θ

[0075] δ5=θ(8);

[0076] Both are three-channel external compression wave system structures. After the design is completed, they converge at the lip at the design point, such as Figure 3 As shown in the figure, the overall length of the Ma 15 design point inlet is 10100mm, which is about 42.3% longer than that of the Ma 8 design point inlet. If the traditional inlet wall internal flow friction resistance is used under hypersonic flow conditions, the cost of structural thermal protection will increase significantly.

[0077] The present invention provides a high Mach number inlet with integrated leading edge shock wave regulation and fuel pre-injection (based on the Ma 8 design point structure), including a lip cover, an inner wall surface, an inlet channel, a front body compression surface, an adjustable wedge fuel injection structure, a wall fuel injection hole, and a high-pressure fuel cavity; and is designed according to the above detailed description. Figure 4 (a) is a cross-sectional view of the air intake duct, and (b) is a top view of the air intake duct.

[0078] The wedge structure is installed at the front edge of the front compression surface. The specific structure is as follows: Figure 5 As shown in the figure, its width is consistent with the width of the compression section in the intake duct. The side wall of the adjustable wedge has a fuel input interface, which is connected to the first high-pressure fuel chamber placed at the front edge of the compression surface of the front body. The fuel is ejected through the cantilever beam on the wedge. The length of the cantilever beam L is determined by the size of the recirculation area behind the wedge, that is, the size of the recirculation area of ​​the wedge needs to be calculated through high-precision numerical simulation. More specific dimensions can be determined in the design iteration stage according to the intake duct and engine performance requirements.

[0079] Furthermore, the rotating shaft on which the wedge block is placed is connected to a rotating motor through a mechanical structure. The rotating motor drives the adjustable wedge block to rotate along with the rotating shaft, and the adjustable wedge block can be adjusted to any position within a limited angle range. Figure 5The control method is described below. The entire structure control will be incorporated into the engine's integrated control system. The integrated control system will determine the use of the adjustable wedge for fuel injection based on the incoming flow conditions and the current working state of the intake duct, and continue to determine the fuel supply requirements based on the current working state requirements of the combustion chamber, thereby ultimately determining the control requirements for wedge adjustment and oil supply. The overall idea is as follows: Figure 2 As shown, the two parts of control requirements will be explained in sequence below.

[0080] (1) Structural adjustment requirements: The fuel injection position of the adjustable wedge is determined by the lifting angle δ0 and the cantilever beam length L. Figure 5 As shown in , according to the current flight flow conditions, it is determined whether to open the adjustable wedge located at the leading edge of the forebody compression surface. At this time, it can be specifically divided into two situations: 1) When the inlet state is in the sub-rated (rated) working state, the adjustable wedge at the leading edge is immersed in the forebody compression surface, and the wall fuel nozzle can be used for fuel pre-injection; 2) When the inlet is in the over-rated state, the adjustable wedge at the leading edge will be lifted, and fuel will be injected through the cantilever beam. According to the compression wave system adjustment requirements, the required wedge lifting angle can be preliminarily obtained by iterative calculation through the shock wave relationship. The specific calculation process is as follows Figure 6 After the wedge lifting angle δ0 is initially determined, Figure 8 As shown in , the size of the recirculation zone can also be established through numerical simulation or experimental means after the specific structure of the intake duct is determined. After the wedge is lifted, a recirculation will occur downstream. At this time, direct injection from the wedge wall may cause the fuel to stagnate in the recirculation zone and form local combustion, which seriously affects the performance of the intake duct. Therefore, injection is performed through a cantilever beam structure with an extended length of L to avoid this phenomenon and increase the fuel premixing efficiency to a certain extent.

[0081] (2) Supply control requirements: After the wedge lifting angle δ0 is preliminarily determined, the fuel premixing efficiency index and whether to open the wall fuel nozzle hole are determined according to the working requirements of the combustion chamber, and finally the specific supply control requirements of the current fuel injection action are given.

[0082] Further, such as Figure 7 As shown in , the fuel jet can form a cooling film effect locally, reducing the wall thermal protection cost. At the same time, it can form a relatively controllable boundary layer combustion through compression shock wave induction, resulting in the effect of reducing wall friction resistance, which affects the overall performance of the engine. The injection strategy can be flexibly adjusted according to the specific situation, such as Figure 2 as shown in .

[0083] Furthermore, by real-time monitoring of the working status of the intake duct and combustion chamber and comparing them with the current target performance requirements, feedback can be generated to make real-time adjustments to the pre-injection strategy.

[0084] In summary, this high Mach number inlet with integrated leading edge shock wave regulation and fuel pre-injection can accept the instructions of the integrated control system, realize the fuel (or other working fluid) pre-injection action through the adjustment control of the adjustable wedge fuel injection structure and the wall fuel nozzle, and can produce functions such as fuel premixing, compression wave system structure regulation, local wall heat protection and wall friction drag reduction, thereby replacing the traditional inlet under higher flight Mach number inflow conditions and improving the overall performance of the engine in many aspects.

[0085] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the present invention and its equivalent technologies, the present invention is also intended to include these changes and variations. The above-described embodiments are only preferred embodiments for fully illustrating the present invention, and their protection scope is not limited thereto. Equivalent substitutions or changes made by those skilled in the art based on the present invention are all within the protection scope of the present invention.

Claims

1. A hypersonic inlet based on leading edge shock wave regulation and fuel pre-injection control, characterized in that: include: A lip cover (1), an inner wall surface of an air inlet passage (2), a front body compression surface (3) and a high-pressure fuel chamber (5); The lip mask (1) is located on the inner wall surface (2) of the air inlet duct, and together with the inner wall surface (2) of the air inlet duct, forms an inner channel (7) of the air inlet duct; The front compression surface (3) is connected to the portion extending forward from the inner wall surface (2) of the air inlet duct; an adjustable wedge fuel injection structure (4) is rotatably provided at the front edge of the front compression surface (3); and wall fuel injection holes (6) are arranged side by side on the front compression surface (3); The high-pressure fuel chamber (5) comprises a first high-pressure fuel chamber and a second high-pressure fuel chamber; the first high-pressure fuel chamber is connected to the adjustable wedge fuel injection structure (4), and the second high-pressure fuel chamber is connected to the wall fuel injection hole (6); a fuel channel is provided inside the adjustable wedge fuel injection structure (4); The adjustable wedge fuel injection structure (4) is provided with a fuel channel inside, one end of the fuel channel is connected to the first high-pressure fuel cavity, and the other end of the fuel channel opens toward the inlet channel (7).

2. The hypersonic inlet based on leading edge shock wave regulation and fuel pre-injection control according to claim 1 is characterized in that: The adjustable wedge fuel injection structure (4) is provided with an outwardly extending cantilever beam at one end facing the inlet channel (7), and an opening at one end of the fuel channel is arranged on the outwardly extending cantilever beam and faces the inlet channel (7).

3. The hypersonic inlet based on leading edge shock wave regulation and fuel pre-injection control according to claim 1 is characterized in that: A rotating shaft is also provided at the front edge of the front compression surface (3), and is rotatably connected to the adjustable wedge fuel injection structure (4) via the rotating shaft.

4. The air intake duct based on leading edge shock wave regulation and fuel pre-injection control according to claim 1, characterized in that: When the adjustable wedge fuel injection structure (4) is not lifted, it is flush with the front body compression surface (3), and the contact surface with the inner part of the air inlet duct entity is an arc surface.

5. The hypersonic inlet based on leading edge shock wave regulation and fuel pre-injection control according to claim 1, characterized in that: The adjustable wedge fuel injection structure (4) has a lifting angle relative to the anterior compression surface (3) in the range of 0-10°.

6. The hypersonic inlet based on leading edge shock wave regulation and fuel pre-injection control according to claim 1, characterized in that: When hydrogen fuel is used, the diameter of the wall fuel injection hole (6) is 1-2 mm, and when kerosene fuel is used, the diameter of the wall fuel injection hole (6) is 0.3-0.5 mm.

7. The hypersonic inlet based on leading edge shock wave regulation and fuel pre-injection control according to claim 1, characterized in that: The front compression surface (3) includes a first compression surface, a second compression surface and a third compression surface extending in the direction of the inlet channel (7); the front end of the second compression surface forms a turning point with the first compression surface, the front end of the front end of the third compression surface forms a turning point with the second compression surface, and the rear end of the third compression surface is connected to the inlet channel inner wall surface (2); the first compression surface is divided into a front section and a rear section at the rear end of the adjustable wedge fuel injection structure (4), the front section is the upper surface of the adjustable wedge fuel injection structure (4), when the adjustable wedge fuel injection structure (4) is in a closed state, the front section and the rear section are in a collinear line, when the adjustable wedge fuel injection structure (4) is in a raised state, the front section and the rear section form an angle, which is equal to the rotation angle of the adjustable wedge fuel injection structure.

8. A control method for a hypersonic inlet based on leading edge shock wave regulation and fuel pre-injection control according to any one of claims 1 to 7, characterized in that: The steps include: S1: After acquiring the flight status, the engine integrated control system determines the required working mode of the air inlet and instructs the air inlet to perform preliminary angle adjustment on the adjustable wedge fuel injection structure; wherein, when the air inlet is in a sub-rated or rated working state, the working mode of the adjustable wedge fuel injection structure is controlled to be closed; when the air inlet is in an over-rated working state, the preliminary lifting angle of the adjustable wedge fuel injection structure is determined according to the compression wave system regulation requirement; S2: Determine the final lifting angle of the adjustable wedge fuel injection structure and the overall injection strategy of the wall fuel injection hole according to the requirements of the downstream combustion organization for fuel mixing efficiency.

9. The method for controlling a hypersonic inlet based on leading edge shock wave regulation and fuel pre-injection control according to claim 8, characterized in that: After completing the preliminary angle adjustment of the adjustable wedge fuel injection structure, it also includes adjusting the overall injection strategy by combining the requirements of the downstream combustion organization for fuel mixing efficiency with the local wall drag reduction and thermal protection requirements.

10. The method for controlling a hypersonic inlet based on leading edge shock wave regulation and fuel pre-injection control according to claim 8, characterized in that: The engine integrated control system acquires the incoming flow parameters in real time, and adjusts the initial lift angle of the adjustable wedge fuel injection structure in real time according to the intake duct performance requirements and the current intake duct performance parameters.

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