Engine and aircraft

Abstract

The embodiment of the present application provides an engine and an aircraft. The engine includes: an intake system, a precooling and supercharging system, a turbocharging system, a ramjet combustion system and an exhaust system; the engine has a first working mode, a second working mode and a third working mode; in the first working mode, after the incoming air enters the turbocharging system for supercharging, it is burned into combustion gas in the turbocharging system and the ramjet combustion system respectively, and finally expands in the exhaust system to generate thrust; in the second working mode, after the incoming air is precooled and supercharged by the precooling and supercharging system, it enters the turbocharging system for supercharging, and is burned into combustion gas in the turbocharging system and the ramjet combustion system respectively, and finally expands in the exhaust system to generate thrust; in the third working mode, the incoming air is burned into combustion gas by the ramjet combustion system, and finally expands in the exhaust system to generate thrust. The engine starts at zero speed and overcomes the problem of "thrust trap", achieving continuous and efficient operation.

Description

Technical Field

[0001] The present application belongs to the field of engine technology, and specifically relates to an engine and an aircraft. Background Art

[0002] With the development of science and technology, aerospace engines have gone through more than a hundred years of development and formed three major branches: aviation turbine engines, rocket engines, and ramjet engines. Due to the high technical maturity, these three types of engines are widely used in their respective fields, but it is difficult to use them across fields. Turbine engines are extremely inefficient when cruising at high Mach numbers; rocket engines have low specific impulse and high propellant consumption, making it difficult to run for a long time; ramjet engines cannot achieve zero-speed start. However, the further development of the aerospace industry requires that the power system must meet the requirements of continuous and efficient operation in a wide speed range (Mach number 0-6 and higher) and large airspace (0-30km and higher) and be reusable. Obviously, it is difficult for the above three types of engines to meet this requirement directly, and people naturally think of combining them appropriately, that is, a combined engine.

[0003] However, although the existing combined engines have their own characteristics, none of them can effectively solve the "thrust trap (Mach 2-4)" problem, and it is difficult to achieve continuous, efficient and repeatable operation at 0-6 Mach. Summary of the invention

[0004] The present application aims to provide an engine and an aircraft to solve the problem that existing combined engines cannot efficiently solve the "thrust trap" problem and it is difficult to achieve continuous, efficient and repeatable operation at 0-6 Mach.

[0005] In order to solve the above technical problems, this application is implemented as follows:

[0006] In a first aspect, the present application discloses an engine for an aircraft, the engine comprising: an intake system, a precooling and supercharging system, a turbocharging system, a ramjet combustion system, and an exhaust system arranged in sequence;

[0007] The engine has at least a first duct and a second duct, the first duct is at least formed in the pre-cooling and supercharging system, and the second duct is at least formed in the ramjet combustion system and the turbocharging system;

[0008] The engine has a first working mode, a second working mode and a third working mode;

[0009] Among them, in the first working mode, the pre-cooling and boosting system is closed, and the incoming air enters the turbocharger system through the second duct for supercharging, and then burns into combustion gas in the turbocharger system and the ramjet combustion system respectively, and finally expands in the exhaust system to generate thrust; in the second working mode, the incoming air enters the pre-cooling and boosting system through the first duct for pre-cooling and supercharging, and then enters the turbocharger system for supercharging, and then burns into combustion gas in the turbocharger system and the ramjet combustion system respectively, and finally expands in the exhaust system to generate thrust; in the third working mode, the incoming air directly enters the ramjet combustion system through the second duct to become combustion gas, and finally expands in the exhaust system to generate thrust.

[0010] Optionally, the operating mode of the engine corresponds to the flight speed of the aircraft; wherein,

[0011] When the speed of the aircraft is 0-2 Mach, the engine operates in the first working mode; when the speed of the aircraft is 2-4 Mach, the engine operates in the second working mode; when the speed of the aircraft is 4-6 Mach, the engine operates in the third working mode.

[0012] Optionally, the engine further comprises: a first switch disposed in the first duct, a second switch disposed in the second duct, and a third switch disposed between the first duct and the second duct; wherein,

[0013] In the first working mode, the first switch is closed to control the first duct to be closed, the second switch is opened to control the second duct to be opened, and the third switch is opened to control the first duct and the second duct to be connected;

[0014] In the second working mode, the first switch is opened to control the first duct to be opened, the second switch is closed to control the second duct to be closed, and the third switch is closed to disconnect the first duct and the second duct;

[0015] In the third working mode, the first switch is closed to control the first duct to be closed, the second switch is opened to control the second duct to be opened, and the third switch is closed to disconnect the first duct and the second duct.

[0016] Optionally, the first switch and the second switch are close to an outlet of the intake system, and the third switch is arranged between the pre-cooling and supercharging system and the turbocharging system.

[0017] Optionally, the precooling and pressurizing system comprises: a precooling fan, a heat exchanger and a low-pressure compressor connected in sequence; wherein,

[0018] The pre-cooling fan is close to the outlet of the air intake system.

[0019] Optionally, the pre-cooling fan is connected to the low-pressure compressor via a driving shaft, and the pre-cooling fan is used to drive the low-pressure compressor to operate.

[0020] Optionally, the turbocharger system comprises a high-pressure compressor, a main combustion chamber and a turbine connected in sequence; wherein,

[0021] The high-pressure compressor is close to the outlet of the pre-cooling and boosting system.

[0022] Optionally, the turbine is connected to the high-pressure compressor via a drive shaft, and the turbine is used to drive the high-pressure compressor to operate.

[0023] Optionally, the ramjet combustion system comprises: a ramjet combustion chamber and the high-pressure compressor; wherein the ramjet combustion chamber is connected to the outlet of the high-pressure compressor.

[0024] Optionally, the exhaust system comprises: a first tail nozzle and a second tail nozzle; wherein,

[0025] The first tail nozzle is connected to the turbine, and the second tail nozzle is connected to the ramjet combustion chamber.

[0026] In a second aspect, the present application also discloses an aircraft, comprising: an engine as described in any one of the above items.

[0027] In the embodiment of the present application, the engine may include an intake system, a precooling and supercharging system, a turbocharging system, a ramjet combustion system and an exhaust system, and may switch between the first working mode, the second working mode and the third working mode. In the first working mode, the incoming air may be pressurized by the turbocharging system and then burned into combustion gas in the turbocharging system and the ramjet combustion system, and finally expand in the exhaust system to generate thrust, so as to solve the problem that the existing ramjet engine cannot achieve zero-speed start. In the second working mode, the incoming air may be precooled and supercharged by the precooling and supercharging system, and then enter the turbocharging system for supercharging, and burn into combustion gas in the turbocharging system and the ramjet combustion system, and finally expand in the exhaust system to generate thrust, so as to solve the problem of "thrust trap" existing in the existing combined engine. In the third working mode, the incoming air directly enters the ramjet combustion system through the second duct to become combustion gas, and finally expands in the exhaust system to generate thrust, so as to achieve high Mach flight. That is, the engine described in the embodiment of the present application can solve the problem of zero-speed starting and overcoming the "thrust trap", and achieve continuous, efficient, repeatable and low-cost operation.

[0028] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0030] Figure 1 is a structural schematic diagram of an engine described in an embodiment of the present application;

[0031] Figure 2 is a comparison chart of the unit thrust of the engine described in the embodiment of the present application and the existing combined engine as a function of Mach;

[0032] Figure 3 It is a comparison chart of the unit specific impulse of the engine described in the application embodiment and the existing combined engine with the change of Mach;

[0033] Figure 4 It is a schematic diagram of the mechanism of another engine described in an embodiment of the present application;

[0034] Figure 5 yes Figure 4 The structural schematic diagram of the engine shown is in the first working mode;

[0035] Figure 6 yes Figure 4 The structural schematic diagram of the engine shown is in the second working mode;

[0036] Figure 7 yes Figure 4 The structural schematic diagram of the engine shown is in the third working mode;

[0037] Figure 8 The engine described in the embodiment of the present application is Figure 5 PV cycle diagram of the working mode shown;

[0038] Fig. 9 The engine described in the embodiment of the present application is Figure 6 PV cycle diagram of the working mode shown;

[0039] Fig.10 The engine described in the embodiment of the present application is Figure 7 PV cycle diagram of the operating mode shown.

[0040] Figure numerals: 10-intake system, 11-intake duct, 20-precooling and boosting system, 21-precooling fan, 22-heat exchanger, 23-low-pressure compressor, 30-turbocharger system, 31-high-pressure compressor, 32-main combustion chamber, 33-turbine, 40-ramjet combustion system, 41-ramjet combustion chamber, 50-exhaust system, 51-first tail nozzle, 52-second tail nozzle, 60-first duct, 61-first switch, 70-second duct, 71-second switch, 72-third switch. DETAILED DESCRIPTION

[0041] Embodiments of the present invention will be described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0042] The term "first" or "second" in the specification and claims of the present application may include one or more of the features explicitly or implicitly. In the description of the present invention, unless otherwise specified, "plurality" means two or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally means that the objects connected before and after are in an "or" relationship.

[0043] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0044] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] Reference Figure 1 , shows a schematic diagram of the structure of an engine according to an embodiment of the present application, such as Figure 1 As shown, the engine may specifically include: an intake system 10, a precooling and supercharging system 20, a turbocharging system 30, a ramjet combustion system 40, and an exhaust system 50, which are arranged in sequence; The engine has at least a first duct 60 and a second duct 70, the first duct 60 is at least connected to the precooling and supercharging system 20, and the second duct 70 is at least formed in the ramjet combustion system 40 and the turbocharger system 30; the engine has a first working mode, a second working mode and a third working mode; wherein, in the first working mode, the precooling and supercharging system is closed, and the incoming air enters the turbocharger system 30 through the second duct 70 for supercharging, and then burns into combustion gas in the turbocharger system 30 and the ramjet combustion system 40 respectively, and finally expands in the exhaust system to generate thrust; in the second working mode, the incoming air enters the precooling and supercharging system 20 through the first duct 60 for precooling and supercharging, and then enters the turbocharger system 30 for supercharging, and burns into combustion gas in the turbocharger system 30 and the ramjet combustion system 40 respectively, and finally expands in the exhaust system to generate thrust; in the third working mode, the incoming air directly enters the ramjet combustion system 40 through the second duct 70 to become combustion gas, and finally expands in the exhaust system to generate thrust.

[0046] In the embodiment of the present application, the engine may include an intake system 10, a precooling and supercharging system 20, a turbocharging system 30, a ramjet combustion system and an exhaust system 50, and may switch between the first working mode, the second working mode and the third working mode. In the first working mode, the incoming air may be pressurized by the turbocharging system 30 and may be burned into combustion gas in the turbocharging system 30 and the ramjet combustion system 40 respectively, and finally expand in the exhaust system to generate thrust, so as to solve the problem that the existing ramjet engine cannot achieve zero-speed start. In the second working mode, the incoming air may be precooled and supercharged by the precooling and supercharging system 20, and then enter the turbocharging system 30 for supercharging, and may be burned into combustion gas in the turbocharging system 30 and the ramjet combustion system 40 respectively, and finally expand in the exhaust system to generate thrust, so as to solve the problem of "thrust trap" existing in the existing combined engine. In the third working mode, the incoming air directly enters the ramjet combustion system 40 through the second duct 70 to become combustion gas, and finally expands in the exhaust system to generate thrust, so as to achieve high Mach flight. That is, the engine described in the embodiment of the present application can solve the problem of zero-speed starting and overcoming the "thrust trap", and achieve continuous, efficient, repeatable and low-cost operation.

[0047] like Figure 1 As shown, the incoming air can be Figure 1The direction indicated by the middle arrow enters the interior of the engine through the intake system 10, and after combustion in the turbocharger system 30 and / or the ramjet combustion system 40 inside the engine, it is finally discharged through the exhaust system 50 to form thrust. The engine may be provided with a first duct 60 and a second duct 70 for air circulation. The first duct 60 may serve as an inner duct of the engine to guide the incoming air to the precooling and supercharging system 20. The second duct 70 may serve as an inner duct of the engine to guide the incoming air to the turbocharger system 30 or the ramjet combustion system 40.

[0048] In the embodiment of the present application, the operating mode of the engine corresponds to the flight speed of the aircraft, so that the engine can operate efficiently and stably at different flight speeds.

[0049] Specifically, when the speed of the aircraft is 0-2 Mach, the engine operates in the first working mode. The first working mode is the turbocharging mode. In this working mode, the incoming air enters the turbocharging system 30 through the second duct 70 and is pressurized, and then burns into combustion gas in the turbocharging system 30 and the ramjet combustion system 40, and finally expands in the exhaust system to generate thrust. Since the incoming air is pressurized by the turbocharging system 30 and then burns and expands to generate thrust, zero-speed starting can be achieved, solving the problem of the existing ramjet engine that cannot start at zero speed.

[0050] When the speed of the aircraft is 2-4 Mach, the engine operates in the second working mode. The second working mode is the pre-cooling and supercharging mode. In this working mode, the incoming air first enters the pre-cooling and supercharging system 20 through the first duct 60 for pre-cooling and supercharging. The pre-cooling and supercharging system 20 maintains the total pressure of the incoming air and reduces the total temperature of the incoming air at 2-3 Mach; increases the total pressure of the incoming air and reduces the total temperature of the incoming air at 3-4 Mach, so that the subsequent turbocharger system 30 can work efficiently at a high Mach number. In this way, the problem of "thrust trap" existing in the existing combined engine at 2-4 Mach can be overcome.

[0051] When the speed of the aircraft is Mach 4-6, the engine operates in the third working mode. The third working mode is the ramjet mode. In this working mode, the high-speed incoming air is pressurized from the second duct 70 and directly enters the ramjet combustion system 40 and is mixed with the fuel for combustion and then directly discharged from the exhaust system 50. The thrust is relatively large, and the high-speed flight of the aircraft can be achieved.

[0052] Reference Figure 2 , which shows a comparison of the unit thrust of the engine described in the embodiment of the present application and the existing combined engine with Mach change. Figure 3, which shows a comparison of the unit specific impulse of the engine described in the embodiment of the present application and the existing combined engine with the change of Mach. Figure 2 and Figure 3 As shown, the existing

[0053] like Figure 2 , Figure 3 As shown, the existing turboramjet combination engine (TBCC), air turbine rocket combination engine (ATR) and rocket ramjet combination engine (RBCC) cannot effectively solve the problem of "thrust trap" at a flight speed of 2-4 Mach. The engine provided in this application can achieve continuous, efficient and repeatable operation at 0~6Ma, effectively solving the problem of "thrust trap". Since the engine provided in the embodiment of this application can achieve efficient, continuous, repeatable and low-cost operation, it is the power equipment of future high Mach number aircraft, and can even open up new ideas for new air and space transportation systems. The social and economic benefits are huge.

[0054] Reference Figure 4 , showing a schematic diagram of another engine structure described in an embodiment of the present application, referring to Figure 5 , showing Figure 4 The schematic diagram of the structure of the engine in the first working mode shown in FIG. Figure 6 , showing Figure 4 The schematic diagram of the structure of the engine in the second working mode shown in FIG. Figure 7 , showing Figure 4 The schematic diagram of the structure of the engine shown is in the third working mode.

[0055] like Figure 4 As shown, the precooling and supercharging system 20 may specifically include: a precooling fan 21, a heat exchanger 22 and a low-pressure compressor 23 connected in sequence; wherein the precooling fan 21 is close to the outlet of the air inlet duct 11 of the air inlet system 10. In a specific application, after the incoming air passes through the air inlet duct 11 of the air inlet system 10 and enters the engine, it may enter the precooling fan 21 through the first duct 60. The incoming air may be reduced in pressure and temperature by the precooling fan 21, and then further reduced in temperature by the heat exchanger 22, and then pressurized and heated by the low-pressure compressor 23. In this process, the total pressure of the incoming air is maintained and the total temperature of the incoming air is reduced under the condition of Mach 2-3; the total pressure of the incoming air is increased and the total temperature of the incoming air is reduced under the condition of Mach 3-4, so that the high-pressure compressor 31 can work efficiently at a high Mach number.

[0056] Optionally, the precooling fan 21 is connected to the low-pressure compressor 23 via a drive shaft, and the precooling fan 21 can be used to drive the low-pressure compressor 23. In this way, it is possible to avoid using an additional separate driving mechanism to drive the low-pressure compressor 23, thereby reducing the number of components inside the engine and simplifying the internal structure of the engine.

[0057] like Figure 4 As shown, the turbocharger system 30 may include a high-pressure compressor 31, a main combustion chamber 32, and a turbine 33 connected in sequence; wherein the high-pressure compressor 31 is close to the outlet of the precooling and supercharging system 20. In a specific application, after the incoming air enters the high-pressure compressor 31, it can be pressurized by the high-pressure compressor 31, and then enter the main combustion chamber 32 to burn and generate combustion gas, and the combustion gas drives the turbine 33 to do work to provide energy for the front high-pressure compressor 31, and then the combustion gas is discharged from the exhaust system 50 to generate thrust.

[0058] In practical applications, turbocharging can improve the engine power and torque. Without changing the engine displacement, turbocharging can significantly improve the engine power and torque. Moreover, turbocharging can also make the engine combustion more efficient, saving 3% to 5% of fuel, thereby improving fuel economy.

[0059] Optionally, the turbine 33 is connected to the high-pressure compressor 31 via a drive shaft, and the turbine 33 can be used to drive the high-pressure compressor 31. In this way, it is possible to avoid using an additional separate driving mechanism to drive the high-pressure compressor 31, thereby reducing the number of parts inside the engine and simplifying the internal structure of the engine.

[0060] Usually, the compressor rotor with high speed is the high-pressure compressor 31, and the compressor rotor with low speed is the low-pressure compressor 23. The maximum speed of the high-pressure compressor 31 is 30,000 rpm, and the maximum speed of the low-pressure compressor 23 can be 20,000 rpm. Specifically in the embodiment of the present application, the high-pressure compressor 31 and the low-pressure compressor are only used to illustrate the speed of the compressor in the pre-cooling and supercharging system 20 and the turbocharging system 30, that is, the speed of the compressor in the turbocharging system 30 is greater than the speed of the compressor in the pre-cooling and supercharging system 20. The embodiment of the present application does not specifically limit the speed of the high-pressure compressor 31 and the low-pressure compressor 23.

[0061] like Figure 4 As shown, the ramjet combustion system 40 may specifically include: a ramjet combustion chamber 41 and a high-pressure compressor 31; wherein the ramjet combustion chamber 41 is connected to the outlet of the high-pressure compressor 31. In a specific application, after the incoming air enters the high-pressure compressor 31, it may be pressurized by the high-pressure compressor 31, and then enter the ramjet combustion chamber 41 to burn and generate combustion gas, and the combustion gas is discharged from the exhaust system 50 to generate thrust.

[0062] like Figure 4As shown, the exhaust system 50 may specifically include: a first tail nozzle 51 and a second tail nozzle 52; wherein the first tail nozzle 51 is connected to the turbine 33, and is used to discharge the gas generated by the combustion of the fuel in the main combustion chamber 32 to form thrust. The second tail nozzle 52 is connected to the ramjet combustion chamber 41, and is used to discharge the gas generated by the combustion of the fuel in the ramjet combustion chamber 41 to form thrust.

[0063] like Figures 5 to 7 As shown, the engine further includes: a first switch 61 disposed in the first duct 60 , a second switch 71 disposed in the second duct 70 , and a third switch 72 disposed between the first duct 60 and the second duct 70 .

[0064] exist Figure 5 In the first working mode shown, the first switch 61 is closed to control the first duct 60 to be closed, the second switch 71 is opened to control the second duct 70 to be opened, and the third switch 72 is opened to control the first duct 60 to be connected to the second duct 70. In this way, the incoming air can enter the second duct 70 through the intake duct 11 and enter the high-pressure compressor 31 through the second duct 70.

[0065] exist Figure 6 In the second working mode shown, the first switch 61 is opened to control the first duct 60 to be opened, the second switch 71 is closed to control the second duct 70 to be closed, and the third switch 72 is closed to disconnect the first duct 60 from the second duct 70. In this way, the incoming air can enter the first duct 60 through the air intake duct 11, and enter the precooling fan 21 through the first duct 60.

[0066] exist Figure 7 In the third working mode shown, the first switch 61 is closed to control the first duct 60 to be closed, the second switch 71 is opened to control the second duct 70 to be opened, and the third switch 72 is closed to disconnect the first duct 60 and the second duct 70. In this way, the incoming air can enter the second duct 70 through the intake duct 11 and directly enter the ramjet combustion chamber 41 through the second duct 70.

[0067] Optionally, the first switch 61 and the second switch 71 are close to the outlet of the intake system 10, so that the first switch 61 controls the opening and closing of the first duct 60, and the second switch 71 controls the opening and closing of the second duct 70. The third switch 72 is arranged between the precooling and supercharging system 20 and the turbocharger system 30, so that the third switch 72 controls the air flow in the second duct 70 to enter the high-pressure compressor 31 or the ramjet combustion chamber 41.

[0068] In a specific application, when the speed of the aircraft is 0-2 Mach, the engine can Figure 5The first working mode shown works. In this mode, the precooling and supercharging system 20 is closed; the incoming air enters the second duct 70, and the third switch 72 plate is in the open state at this time, and the airflow in the second duct 70 directly enters the high-pressure compressor 31. After being pressurized by the high-pressure compressor 31, the air flow is divided into two streams: the first stream enters the main combustion chamber 32 for combustion, and the gas drives the turbine 33 to do work to provide energy for the front high-pressure compressor 31, and then the gas is discharged from the first tail nozzle 51 to generate the first part of the engine's thrust; the second stream of air enters the ramjet combustion chamber 41 of the outer ring of the main combustion chamber 32 and is mixed with the fuel and burned, and then is directly discharged from the second tail nozzle 52 to generate the second part of the thrust. The combined force of the two parts of the thrust is the total thrust of this type of engine.

[0069] When the speed of the aircraft is 2-4 Mach, the engine can Figure 6 The second working mode shown in the figure works. In this mode, the second duct 70 is closed, the incoming air enters the first duct 60, then flows through the precooling fan 21 to reduce the pressure and temperature, and then flows through the heat exchanger 22 to further reduce the air flow temperature, and then pressurizes and heats up through the low-pressure compressor 23. This process maintains the total pressure of the incoming air and reduces the total temperature of the incoming air under the condition of 2-3 Mach; increases the total pressure of the incoming air and reduces the total temperature of the incoming air under the condition of 3-4 Mach, so that the high-pressure compressor 31 can work efficiently at a high Mach number. After being pressurized by the low-pressure compressor 23, the air flows into the high-pressure compressor 31 for further pressurization and is divided into two streams of air: the first stream enters the main combustion chamber 32 for combustion, and the gas drives the turbine 33 to do work to provide energy for the high-pressure compressor 31 at the front end, and then the gas is discharged from the first tail nozzle 51 to generate the first part of the engine's thrust; the second stream of air enters the ramjet combustion chamber 41 of the outer ring of the main combustion chamber 32 and is mixed with the fuel and burned, and then is directly discharged from the second tail nozzle 52 to generate the second part of the thrust. The combined force of the two thrusts is the total thrust of this type of engine.

[0070] When the speed of the aircraft is 4-6 Mach, the engine can Figure 7 The third working mode shown in the figure works. In this mode, the first duct 60 is completely closed, that is, the precooling and supercharging system 20 and the turbocharging system 30 are both closed; the high-speed incoming air enters the second duct 70 and is supercharged, directly enters the ramjet combustion chamber 41, mixes with the fuel and burns, and then is directly discharged from the second tail nozzle 52 to generate the total thrust of the engine.

[0071] Reference Figure 8 , showing the engine described in the embodiment of the present application Figure 5 Refer to the PV cycle diagram of the working mode shown in Fig. 9 , showing the engine described in the embodiment of the present application Figure 6 Refer to the PV cycle diagram of the working mode shown in Fig.10, showing the engine described in the embodiment of the present application Figure 7 PV cycle diagram of the operating mode shown.

[0072] It should be noted that Figures 8 to 10 The PV cycle diagram shown is based on the following assumptions: 1. The airflow or gas involved in the embodiments of the present application is a perfect gas, and the flow is one-dimensional and steady; 2. The airflow has its own constant-pressure specific heat capacity, constant-volume specific heat capacity and specific heat ratio when flowing through the air inlet 11, the precooling fan 21, the high-pressure compressor 31, the turbine 33 and the tail nozzle; 3. When the airflow flows through the combustion chamber, the afterburner and the mixing chamber, the value is changing.

[0073] For ease of explanation, different cross sections may be taken at different locations within the engine. Figures 4 to 6 As shown, section 0 is the air far field, section 1 is the inlet of the air inlet 11, section 2 is the outlet of the air inlet 11, section 2.1 is the outlet of the precooling fan 21, section 2.2 is the outlet of the heat exchanger 22, section 3.1 is the outlet of the low-pressure compressor 23, section 3.2 is the outlet of the high-pressure compressor 31, section 4 is the outlet of the main combustion chamber 32, section 5.1 is the outlet of the turbine 33, 5.2 is the outlet of the ramjet combustion chamber 41, section 9.2 is the outlet of the tail nozzle, and sections 7.1, 8.1 and 9.1 are the inlet, throat and outlet of the convergent-divergent tail nozzle.

[0074] like Figure 8 As shown, in the first working mode: 1-2 is the isentropic compression process in the air inlet 11; 2-3.2 is the isentropic compression process in the compressor; 3.2-4 is the isobaric combustion process of air with a relative air entrainment amount of e in the main combustion chamber 32; 4-5.1 is the isentropic expansion process of air with a relative air entrainment amount of e in the turbine 33; 6-9.2 is the isentropic expansion process of air with a relative air entrainment amount of e in the first tail nozzle 51; 3.2-5.2 is the isobaric combustion process of air with a relative air entrainment amount of 1-e in the ramjet combustion chamber 41; 5.2-9.1 is the isentropic expansion process of air with a relative air entrainment amount of 1-e in the second tail nozzle 52; 9.1-1 is the isobaric heat release process in the atmosphere.

[0075] like Fig. 9As shown, in the second working mode: 1-2.1 is the isentropic expansion process in the precooling fan 21; 2.1-2.2 is the isobaric heat release process in the heat exchanger 22; 2.2-3.1 and 3.1-3.2 are the isentropic compression processes in the low-pressure compressor 23 and the high-pressure compressor 31 respectively; 3.2-4 is the isobaric combustion process of air with a relative air entrainment amount of e in the combustion chamber; 4-5.1 is the isentropic expansion process of air with a relative air entrainment amount of e in the turbine 33; 5.1-9.2 is the isentropic expansion process of air with a relative air entrainment amount of e in the first tail nozzle 51; 3.2-5.2 is the isobaric combustion process of air with a relative air entrainment amount of 1-e in the ramjet combustion chamber 41; 4-9.1 is the isentropic expansion process of air with a relative air entrainment amount of 1-e in the second tail nozzle 52; 9.1-1.2 is the isobaric heat release process in the atmosphere.

[0076] like Fig.10 As shown, in the ramjet mode, 1-2 is the isentropic compression process in the inlet 11; 2-5.2 is the isobaric combustion process in the ramjet combustion chamber 41; 5.2-9.1 is the isentropic expansion process in the second tail nozzle 52. In summary, the engine described in the embodiment of the present application can at least include the following advantages:

[0077] In the embodiment of the present application, the engine may include an intake system, a precooling and supercharging system, a turbocharging system, a ramjet combustion system and an exhaust system, and may switch between the first working mode, the second working mode and the third working mode. In the first working mode, the incoming air may be pressurized by the turbocharging system and then burned into combustion gas in the turbocharging system and the ramjet combustion system, and finally expand in the exhaust system to generate thrust, so as to solve the problem that the existing ramjet engine cannot achieve zero-speed start. In the second working mode, the incoming air may be precooled and supercharged by the precooling and supercharging system, and then enter the turbocharging system for supercharging, and burn into combustion gas in the turbocharging system and the ramjet combustion system, and finally expand in the exhaust system to generate thrust, so as to solve the problem of "thrust trap" existing in the existing combined engine. In the third working mode, the incoming air directly enters the ramjet combustion system through the second duct to become combustion gas, and finally expands in the exhaust system to generate thrust, so as to achieve high Mach flight. That is, the engine described in the embodiment of the present application can solve the problem of zero-speed starting and overcoming the "thrust trap", and achieve continuous, efficient, repeatable and low-cost operation.

[0078] The present application also provides an aircraft, which may include the engine described in any of the above embodiments. The aircraft may include but is not limited to at least one of an aircraft, a spacecraft, and a high Mach aircraft. The present application does not specifically limit the type of the aircraft.

[0079] It should be noted that in the embodiment of the present application, the structure of the engine of the aircraft is the same as the structure of the engine described in any of the above embodiments, and its beneficial effects are also similar, which will not be repeated here.

[0080] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0081] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An engine for an aircraft, characterized in that: The engine comprises: an intake system (10), a precooling and supercharging system (20), a turbocharging system (30), a ramjet combustion system (40), and an exhaust system (50) which are arranged in sequence; The precooling and pressurizing system (20) comprises: a precooling fan (21), a heat exchanger (22), and a low-pressure compressor (23) connected in sequence; wherein the precooling fan (21) is close to the outlet of the air intake system (10); The turbocharging system (30) comprises a high-pressure compressor (31), a main combustion chamber (32), and a turbine (33) connected in sequence; wherein the high-pressure compressor (31) is close to an outlet of the precooling and supercharging system (20); The engine has at least a first duct (60) and a second duct (70), the first duct (60) being formed at least in the pre-cooling and supercharging system (20) and the turbocharging system (30), and the second duct (70) being formed at least in the ramjet combustion system (40); The engine further comprises: a first switch (61) arranged at the first duct (60), a second switch (71) arranged at the second duct (70), and a third switch (72) arranged between the first duct (60) and the second duct (70); The engine has a first working mode, a second working mode and a third working mode; Wherein, in the first working mode, the first switch (61) is closed to control the first duct (60) to be closed, the second switch (71) is opened to control the second duct (70) to be opened, and the third switch (72) is opened to control the first duct (60) and the second duct (70) to be connected; the precooling and supercharging system is closed, and the incoming air enters the turbocharger system (30) through the second duct (70) for supercharging, and then burns into combustion gas in the turbocharger system (30) and the ramjet combustion system (40), and finally expands in the exhaust system to generate thrust; In the second working mode, the first switch (61) is opened to control the first duct (60) to be opened, the second switch (71) is closed to control the second duct (70) to be closed, and the third switch (72) is closed to disconnect the connection between the first duct (60) and the second duct (70); the incoming air enters the precooling and supercharging system (20) through the first duct (60) for precooling and supercharging, then enters the turbocharging system (30) for supercharging, and is respectively burned in the turbocharging system (30) and the ramjet combustion system (40) to become combustion gas, and finally expands in the exhaust system to generate thrust; In the third working mode, the first switch (61) is closed to control the first duct (60) to be closed, the second switch (71) is opened to control the second duct (70) to be opened, and the third switch (72) is closed to disconnect the first duct (60) and the second duct (70); the incoming air directly enters the ramjet combustion system (40) through the second duct (70) to become combustion gas, and finally expands in the exhaust system to generate thrust.

2. The engine according to claim 1, characterized in that The working mode of the engine corresponds to the flight speed of the aircraft; wherein, When the speed of the aircraft is 0-2 Mach, the engine operates in the first working mode; when the speed of the aircraft is 2-4 Mach, the engine operates in the second working mode; when the speed of the aircraft is 4-6 Mach, the engine operates in the third working mode.

3. The engine according to claim 1, characterized in that The first switch (61) and the second switch (71) are located close to an outlet of the air intake system (10), and the third switch (72) is arranged between the pre-cooling and supercharging system (20) and the turbocharging system (30).

4. The engine according to claim 1, characterized in that The precooling fan (21) is connected to the low-pressure compressor (23) via a drive shaft, and the precooling fan (21) is used to drive the low-pressure compressor (23) to operate.

5. The engine according to claim 1, characterized in that The turbine (33) is connected to the high-pressure compressor (31) via a drive shaft, and the turbine (33) is used to drive the high-pressure compressor (31) to work.

6. The engine according to claim 1, characterized in that The ramjet combustion system (40) comprises a ramjet combustion chamber (41).

7. The engine according to claim 6, characterized in that The exhaust system (50) comprises: a first tail nozzle (51) and a second tail nozzle (52); wherein: The first tail nozzle (51) is connected to the turbine (33), and the second tail nozzle (52) is connected to the ramjet combustion chamber (41).

8. An aircraft, characterized in that: The aircraft comprises: the engine according to any one of claims 1 to 7.

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