Boundary layer suction type propulsion system and airplane

Abstract

The invention discloses a boundary layer suction type propulsion system and an aircraft. The propelling system comprises an open type rotor engine and a BLI fan. A part of energy of fuel combustion of the open type rotor engine is used for driving a rotor of the open type fan to rotate to serve as propelling power. The other part of fuel chemical energy is converted into electric energy which is transmitted to a BLI fan installed on the rear portion of the fuselage, and the electric energy drives the BLI fan to rotate so as to provide the other part of propelling power.

Description

Technical Field

[0001] The invention relates to a boundary layer suction propulsion system and an aircraft. Background Art

[0002] ICAO and related scientific research institutions have increasingly stringent requirements for fuel consumption, environmental protection and other indicators of future aircraft. According to reports, NASA and the European Union hope to reduce aircraft fuel consumption by 70% by 2035 (N+3 time frame). However, aircraft engines based on conventional fuel configurations can no longer meet this requirement. Therefore, a solution for the propulsion system of aircraft engines that further reduces fuel consumption is needed in this field.

[0003] At present, the scheme for reducing fuel consumption may include, for example, the use of a BLI fan, that is, a boundary layer ingestion fan (BLI fan, boundary layer ingestion fan) installed at the tail of the aircraft. The propulsive fuel system concept has become a research hotspot.

[0004] The basic idea of ​​this configuration is to add a fan to the tail of a traditional aircraft, which is usually directly driven by the electricity generated by the operation of a conventional gas turbine engine. When the tail fan is working, it can effectively inhale the gas boundary layer that gradually accumulates on the fuselage surface due to the viscosity, thereby reducing the accumulation of the fuselage boundary layer, effectively reducing the resistance of the aircraft, and ultimately achieving the purpose of reducing the range and fuel consumption. Due to the boundary layer suction effect of the tail fan, foreign countries usually call this fan a boundary layer ingestion fan (BLI fan), so it is referred to as a BLI fan in the application documents of this application.

[0005] On the other hand, the BLI fan also provides about 20% to 30% thrust. Therefore, when the total thrust demand of the aircraft remains unchanged, the thrust demand of the conventional gas turbine engine is reduced, so its fan diameter can also be reduced, making it easier to meet the size constraints under the maximum diameter of the nacelle.

[0006] Due to the boundary layer suction effect of the BLI fan, it is equivalent to indirectly increasing the bypass ratio of the traditional gas turbine engine. However, the effect of reducing fuel consumption of the thrust system using the BLI fan needs to be further improved.

[0007] Among the current solutions to reduce fuel consumption, there is an open rotor engine, for example, which is an engine between a turboprop and a turbofan. Since it can be seen as an ultra-high bypass ratio turbofan engine without the outer duct, it has the advantages of high propulsion efficiency and low fuel consumption of a turboprop engine and high flight speed of a turbofan engine. It is one of the important research directions for future high-performance engine configurations, but it has defects such as noise, and it is difficult to meet the relevant requirements of civil aviation for noise. Summary of the invention

[0008] The object of the present invention is to provide a boundary layer suction propulsion system.

[0009] The object of the present invention is to provide an aircraft.

[0010] According to the first aspect of the present invention, the boundary layer suction propulsion system includes: an open rotor engine and a BLI fan; wherein a part of the energy from the fuel combustion of the open rotor engine is used to drive the rotor of the open fan to rotate as a propulsion power; another part of the fuel chemical energy is converted into electrical energy and transmitted to the BLI fan installed at the rear of the fuselage, and the electrical energy drives the BLI fan to rotate to provide another part of the propulsion power.

[0011] In one embodiment, the propulsion system further includes a rechargeable battery, and in take-off and climbing conditions, the rechargeable battery supplies power to the BLI fan.

[0012] In one embodiment, during cruising and descent conditions, the electrical energy converted from the other part of the fuel chemical energy is also provided to charge the rechargeable battery.

[0013] In one embodiment, during descent, landing, and taxiing conditions, the open rotor engine is turned off, and the rechargeable battery supplies power to the BLI fan to provide all power.

[0014] In one embodiment, during landing conditions, the BLI fan is reversed to provide at least partial reverse thrust.

[0015] In one embodiment, the open rotor engine has no thrust reverser, and the BLI fan reverses to provide all of the reverse thrust.

[0016] In one embodiment, the open rotor engine includes a propulsion or traction structure.

[0017] In one embodiment, the annular motor stator is embedded and installed inside the BLI fan nacelle, and the tip portion of the BLI fan rotor is connected to the annular motor rotor and driven to rotate thereby, providing part of the forward thrust.

[0018] An aircraft according to a second aspect of the present invention comprises one or more boundary layer suction propulsion systems as described above.

[0019] In one embodiment, the inlet support plate of the BLI fan and the BLI fan stator are mounted on the fuselage of the aircraft to support the nacelle of the BLI fan.

[0020] According to the technical solution of the present invention, one or a combination of the following technical effects can be obtained:

[0021] 1. The combination of BLI fan and open rotor engine constructs a hybrid power system of BLI fan, open rotor engine and rechargeable battery, which not only realizes the high propulsion efficiency brought by the large bypass ratio of the open fan and the boundary layer suction effect of the BLI fan, but also can significantly reduce the fuel consumption required by the entire propulsion system under the same thrust conditions. In addition, during descent, landing and ground taxiing, only the battery can be used to drive the BLI fan to provide power, reducing ground noise and combustion chamber pollutant emissions. On the basis of reducing fuel consumption, the synergistic effect of the three achieves the effect of reducing noise.

[0022] 2. The reverse thrust function during landing can be achieved through the reversal of the BLI fan, and there is no need to consider the variable pitch function. The open rotor engine structure is also simpler, easier to repair and maintain, and the reliability of the entire machine structure is improved.

[0023] 3. The BLI fan is installed on the outside of the tail fuselage, and a ring-shaped motor belt is used to drive the BLI fan rotor, which can avoid the problems of limited installation space, structural strength and motor heat dissipation caused by installing the motor in the tail hub. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which:

[0025] Figure 1 This is a general diagram of an aircraft, an open rotor engine, and a BLI fan according to an embodiment.

[0026] Figure 2 Schematic diagram of an open rotor engine installed under the wing of an aircraft.

[0027] Figure 3A , Figure 3B They are schematic diagrams of the two-dimensional cross-sectional structures of propulsion and traction open rotor engines respectively.

[0028] FIG. 4A to FIG. 4C A schematic diagram of the installation structure of a BLI fan of a propulsion system on a fuselage according to an embodiment. DETAILED DESCRIPTION

[0029] The present invention is further described below in conjunction with specific embodiments and drawings. More details are elaborated in the following description to facilitate a full understanding of the present invention. However, the present invention can obviously be implemented in a variety of other ways different from the description herein. Those skilled in the art can make similar generalizations and deductions based on actual application situations without violating the connotation of the present invention. Therefore, the protection scope of the present invention should not be limited by the content of this specific embodiment.

[0030] like Figure 1 , which is a schematic diagram of the overall structure of an aircraft, an open rotor engine, and a BLI fan. An open rotor engine 300 is installed on each side of the wing of the aircraft 1. A lithium battery pack 4 is installed in the body of the aircraft 1 as a rechargeable battery. It can be understood that the rechargeable battery is not limited to a lithium battery, and can also be other common rechargeable batteries. In addition, a BLI fan 500 is installed at the rear of the aircraft 1.

[0031] like Figure 1 As shown, the open rotor engines 300 installed on both sides of the aircraft 1 use conventional fuel (such as aviation kerosene) as fuel, but are not limited thereto and may also use other fuels. A portion of the energy from the fuel combustion is used to drive the open fan rotor 308 of the open rotor engine to rotate as a propulsion power, and the airflow passing through the open fan rotor 308 then flows through the open fan stator 310 for rectification, such as Figure 2 As shown, the propulsion power is outputted. It can be understood that the open fan stator 310 can also be changed to a rotating counter-rotating blade to output the propulsion power.

[0032] like Figure 1 As shown, another part of the fuel chemical energy will be converted into electrical energy and transmitted to the BLI fan 500 installed at the rear of the fuselage through the aircraft cable 2. The electrical energy drives the BLI fan 500 to rotate to provide another part of the propulsion power. This part of the thrust can account for 10% to 30% of the thrust of the entire propulsion system.

[0033] In the take-off condition, in addition to the open rotor engine 300 providing power to the BLI fan 500, the lithium battery 4 placed inside the aircraft 1 can also provide auxiliary power supply; in the flight conditions such as cruising and descent, the power generated by the open rotor engine 300 is not only provided to the BLI fan 500, but the excess power can be used to charge the lithium battery pack 4, so that the excess power is stored in the lithium battery pack 4 inside the aircraft 1. In the descent, landing, and taxiing stages, the open rotor engine 300 can be turned off, and the lithium battery pack 4 can supply power to the BLI fan 500 to provide all the power of the propulsion system, so as to achieve the purpose of reducing the pollutant emissions and noise of the combustion chamber.

[0034] The beneficial effect of this is that the combination of the BLI fan and the open rotor engine constructs a hybrid power system of the BLI fan, the open rotor engine and the rechargeable battery, which not only realizes the high propulsion efficiency brought by the large bypass ratio of the open fan and the boundary layer suction effect of the BLI fan, but also can significantly reduce the fuel consumption required for the entire propulsion system under the same thrust conditions. In addition, during descent, landing and ground taxiing, only the battery can be used to drive the BLI fan to provide power, thereby reducing ground noise and combustion chamber pollutant emissions. On the basis of reducing fuel consumption, the synergistic effect of the three achieves the effect of reducing noise.

[0035] During landing, the BLI fan 500 can be reversed to achieve reverse thrust, shorten the landing distance, and even replace the reverse thrust device in the open rotor engine 300, thereby simplifying the engine structure, reducing the engine weight, and increasing the reliability of the open rotor engine 300. The reverse rotation of the BLI fan can achieve at least a partial reverse thrust function during landing, and even the variable pitch function (i.e., no reverse thrust device) is required, and the BLI fan can achieve the full reverse thrust function, which not only makes the structure of the open rotor engine in the propulsion system more concise and convenient for repair and maintenance, but also improves the structural reliability of the entire system.

[0036] As shown in FIG3 , it is a schematic diagram of the structure of an open rotor engine 300. Since open fans are divided into two types: a propulsion type in which the fan rotor blades are at the rear of the engine and a traction type in which the fan rotor blades are at the front, these two types are described separately here:

[0037] 1) Push-type

[0038] like Figure 3AAs shown, after the incoming air is compressed by the compressor 301a, it enters the combustion chamber 303a and burns with the fuel. The gas enters and drives the high-pressure turbine 304a to rotate. The high-pressure turbine 304a is connected to the compressor 301a through the high-pressure shaft 302a, driving the compressor to rotate and compress the air. After the gas flows through the high-pressure turbine 304a, it enters the power turbine 305a to drive it to rotate. The power turbine 305a drives the low-pressure shaft 306a. The reducer 307a is respectively connected to the left low-pressure shaft 306a and the right fan disk assembly 309a, driving the open rotor rotor 308a to rotate and provide thrust. The open fan stator 310a is fixed to the open rotor engine tail cone 314a through the mounting assembly 311a. The motor shaft 315a is connected to the reducer 307a and the motor 313a respectively. The motor 313a is fixed in the tail cone 314a through the mounting support plate 312a and is driven to rotate by the motor shaft 315a, converting part of the chemical energy of combustion into electrical energy through mechanical energy. In addition, in high thrust conditions such as takeoff and climbing, the motor 313a can also use the power of the battery pack 4a to provide auxiliary energy to the fan rotor 308a to rotate and generate thrust.

[0039] 2) Traction type

[0040] like Figure 3BAs shown, after the incoming air is compressed by the compressor 306b, it enters the combustion chamber 308b and burns with the fuel, and the combustion gas enters the high-pressure turbine 309b and drives it to rotate. The high-pressure turbine 309b is connected to the high-pressure compressor 306b through the high-pressure disk shaft / structure 307b, which can drive the high-pressure compressor 306b to rotate and compress the air. The combustion gas leaving the high-pressure turbine 309b enters the low-pressure turbine 311b and drives it to rotate. The low-pressure turbine 311b is connected to the low-pressure turbine disk 312b and the low-pressure shaft 310b, and can drive the reduction gear box 304b connected to the left side of the low-pressure shaft 310b. The left side of the reduction gear box 304b is connected to the fan shaft 303b, and the left side of the fan shaft 303b is connected to the actuator 302b. The actuator structure 302b mainly supports and drives the fan rotor 301b to rotate. The rotation of the fan rotor 301b generates thrust by compressing the incoming air. After the fan stator 305b is installed on the fan rotor 301b, its root is connected and fixed with the open fan hub 314b, which can play a role in rectifying the air. In addition, a variable pitch adjustment structure can be installed in the fan hub 314b to change the pitch angle of the fan stator 305, thereby changing the thrust and aerodynamic efficiency of the open fan 300b, or playing a role of reverse thrust. The motor 313b is installed inside the tail cone of the open fan, and it is connected to the low-pressure shaft 310b at the same time as the low-pressure turbine 311b. Through the power supply of the fuselage battery pack 4b, the motor 313b can provide auxiliary energy to the fan rotor blades 301b in high-thrust flight conditions such as take-off and climbing, thereby reducing fuel consumption and carbon dioxide emissions. In low-thrust conditions such as cruising and descent, the low-pressure turbine 311b can drive the motor 313b to rotate and generate electricity, and the generated electricity will be stored in the battery pack 4b.

[0041] like FIG. 4A to FIG. 4C The structure diagram of the BLI fan 500 is shown. The structure of the motor that drives the BLI fan to rotate is the structure of a ring motor. The ring motor stator 5031 of the ring motor 503 is embedded and installed inside the BLI fan nacelle 505, and the tip part of the fan rotor 502 of the BLI fan is connected to the ring motor rotor 5032 of the ring motor and driven to rotate thereby, providing a part of the forward thrust. The BLI fan inlet support plate 501 and the fan stator 504 of the BLI fan are installed on the fuselage 1, supporting the BLI fan nacelle. The beneficial effect of this is that the BLI fan is installed on the outside of the tail fuselage, and the ring motor belt is used to drive the BLI fan rotor, which can avoid the problems of limited installation space, structural strength and motor heat dissipation caused by the motor being installed in the tail hub, thereby simplifying the structure of the BLI fan.

[0042] In summary, the beneficial effects of the boundary layer suction propulsion system and the aircraft described in the above embodiments include but are not limited to one or a combination of the following:

[0043] 1. The combination of BLI fan and open rotor engine constructs a hybrid power system of BLI fan, open rotor engine and rechargeable battery, which not only realizes the high propulsion efficiency brought by the large bypass ratio of the open fan and the boundary layer suction effect of the BLI fan, but also can significantly reduce the fuel consumption required by the entire propulsion system under the same thrust conditions. In addition, during descent, landing and ground taxiing, only the battery can be used to drive the BLI fan to provide power, reducing ground noise and combustion chamber pollutant emissions. On the basis of reducing fuel consumption, the synergistic effect of the three achieves the effect of reducing noise.

[0044] 2. The reverse thrust function during landing can be achieved through the reversal of the BLI fan, and there is no need to consider the variable pitch function. The open rotor engine structure is also simpler, easier to repair and maintain, and the reliability of the entire machine structure is improved.

[0045] 3. The BLI fan is installed on the outside of the tail fuselage, and a ring-shaped motor belt is used to drive the BLI fan rotor, which can avoid the problems of limited installation space, structural strength and motor heat dissipation caused by installing the motor in the tail hub.

[0046] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. A boundary layer suction propulsion system, characterized in that: include: Open rotor engines, and BLI fan; Part of the energy from the fuel combustion of the open rotor engine is used to drive the rotor of the open fan to rotate as propulsion power; Another part of the fuel's chemical energy is converted into electrical energy and transmitted to the BLI fan installed at the rear of the fuselage. The electrical energy drives the BLI fan to rotate to provide another part of the propulsion power.

2. The propulsion system according to claim 1, characterized in that The propulsion system also includes a rechargeable battery, which provides electrical energy to the BLI fan during takeoff and climb conditions.

3. The propulsion system according to claim 2, characterized in that In cruising and descent conditions, the electrical energy converted from the other part of the fuel chemical energy is also provided to charge the rechargeable battery.

4. The propulsion system according to claim 2, characterized in that During descent, landing, and taxiing conditions, the open rotor engine is turned off, and the rechargeable battery supplies power to the BLI fan to provide all power.

5. The propulsion system according to claim 1, characterized in that During landing conditions, the BLI fan is reversed to provide at least partial reverse thrust.

6. The propulsion system according to claim 1, characterized in that The open rotor engine has no reverse thrust device, and the BLI fan reverses to provide all the reverse thrust.

7. The propulsion system according to claim 1, characterized in that The open rotor engine includes a propulsion type or a traction type structure.

8. The propulsion system according to claim 1, characterized in that The ring motor stator is embedded in the BLI fan nacelle. The tip of the BLI fan rotor is connected to the ring motor rotor and driven to rotate by it, providing part of the forward thrust.

9. An aircraft, characterized in that: It comprises arranging one or more boundary layer suction propulsion systems as described in claims 1-8.

10. The aircraft according to claim 9, characterized in that The inlet support plate of the BLI fan and the BLI fan stator are mounted on the fuselage of the aircraft to support the nacelle of the BLI fan.

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