Embedded type air inlet channel structure with adjustable boundary layer separation channel

Abstract

The invention provides an embedded type air inlet channel structure with an adjustable boundary layer separation channel, and belongs to the field of aircraft design, the embedded type air inlet channel structure comprises an aircraft body and an engine located in the aircraft body, the upper surface of the aircraft body is provided with an inlet flow guide slope section, the inlet flow guide slope section inclines downwards, and therefore a sunken embedded type air inlet is formed in the inlet flow guide slope section; an engine air inlet pipeline and a boundary layer exhaust pipeline are arranged in the machine body on the rear side of the inlet flow guide slope section, the engine air inlet pipeline is connected with the embedded air inlet and the engine and used for guiding airflow of the embedded air inlet into the engine, and the boundary layer exhaust pipeline is connected with the embedded air inlet and the lower side face of the machine body and used for guiding airflow of the embedded air inlet into the engine. Air flow of the embedded air flow port is led out from the interior of the machine body; wherein a tongue plate capable of controlling deflection is arranged at the combined part of the air inlet pipeline of the engine and the boundary layer removal pipeline, and the area proportion or the flow ratio of airflow flowing to the air inlet pipeline of the engine and the boundary layer removal pipeline at the embedded air inlet is adjusted by controlling the deflection of the tongue plate.

Description

Technical Field

[0001] This application belongs to the field of aircraft design technology, and specifically relates to an embedded air intake structure with adjustable boundary layer diverter. Background Technology

[0002] Embedded air intakes, by burying the air inlet within the fuselage, reduce the aircraft's frontal area and drag, while also lowering the radar cross-section (RCS), thus improving the aircraft's survivability. However, embedded air intakes also have some drawbacks. For example, when the aircraft is flying at high speed and the engine is operating at low flow rates, the airflow at the inlet section is prone to flow separation due to the large adverse pressure gradient, which can affect engine performance. Furthermore, during low-speed takeoff, the embedded air intake only has lip flow around one side, resulting in higher intake distortion at low speeds. This limits the operational range of embedded air intakes and restricts their application in aircraft. Summary of the Invention

[0003] The purpose of this application is to provide an embedded intake structure with adjustable boundary layer diverters to solve or mitigate at least one of the problems in the prior art.

[0004] The technical solution of this application is: an adjustable boundary layer diverter embedded air intake structure, including: a body and an engine located inside the body, the upper surface of the body is provided with an inlet guide slope section, the inlet guide slope section is inclined downward, thereby forming a recessed embedded air intake at the inlet guide slope section, the body behind the inlet guide slope section is provided with an engine air intake pipe and a boundary layer exhaust pipe, the engine air intake pipe connects the embedded air intake and the engine, and is used to guide the airflow of the embedded inlet into the engine, the boundary layer exhaust pipe connects the embedded air intake and the lower side of the body, and is used to exhaust the airflow of the embedded air intake from the inside of the body;

[0005] The junction of the engine intake duct and the boundary layer exhaust duct is provided with a controllable deflection tongue plate. By controlling the deflection of the tongue plate, the area ratio or flow rate ratio of the airflow at the embedded air intake to the engine intake duct and the boundary layer exhaust duct is adjusted.

[0006] Preferably, the reference position of the tongue plate is determined based on the engine's maximum flow rate during high-speed cruise flight as the design point.

[0007] Preferably, the tongue plate is installed at the junction of the engine intake pipe and the boundary layer exhaust pipe via a control device, the control device including a servo motor.

[0008] Preferably, the connection between the inlet guide slope section and the boundary layer discharge pipe forms an outwardly protruding structure, and the shape of the tongue plate is adapted to the outwardly protruding structure.

[0009] Preferably, the outer front end of the engine intake pipe is provided with a lip.

[0010] Preferably, the engine is a jet engine.

[0011] The adjustable boundary layer diverter embedded air intake provided in this application controls the inlet area distribution of the boundary layer exhaust pipe and the engine air intake pipe by adjusting the position of the tongue plate, thereby enabling the embedded air intake to maintain good aerodynamic performance under a wide range of flight Mach numbers and airflow conditions, and expanding the application range of the air intake. Attached Figure Description

[0012] To more clearly illustrate the technical solutions provided in this application, the accompanying drawings will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application.

[0013] Figure 1 This is a schematic diagram of the embedded intake structure of the adjustable boundary layer diverter of this application.

[0014] Figure 2 This is a schematic diagram showing the different adjustment positions of the tongue plate in this application. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings.

[0016] This application provides a recessed air intake system that utilizes an adjustable boundary layer diverter tongue to extend the normal operating range of the recessed air intake, enabling it to operate normally under a wider range of airflow and flight speed.

[0017] like Figure 1 and Figure 2 As shown, the embedded air intake structure of the adjustable boundary layer diverter provided in this application includes: a body 1 and an engine 2, wherein the engine 2 is disposed inside the body 1.

[0018] The upper surface of the fuselage 1 is provided with an inlet guide slope 3, which slopes downwards to form a recessed embedded air intake. Behind the inlet guide slope 3, within the fuselage 1, are an engine intake duct 4 and a boundary layer exhaust duct 5. The engine intake duct 4 connects the embedded air intake to the engine 2, guiding the airflow from the embedded inlet into the engine 2. The boundary layer exhaust duct 5 connects the embedded air intake to the lower side of the fuselage 1, exhausting the airflow from the embedded air intake from inside the fuselage 1. A controllable deflection tongue 6 is provided at the junction of the engine intake duct 4 and the boundary layer exhaust duct 5. By controlling the deflection of the tongue 6, the area ratio or flow rate ratio of the airflow from the embedded air intake to the engine intake duct 4 and the boundary layer exhaust duct 5 can be adjusted.

[0019] In some embodiments of this application, the tongue plate 6 can be connected to the junction of the engine intake pipe 4 and the boundary layer exhaust pipe 5 by a servo motor, so that the deflection of the tongue plate 6 can be controlled by the servo motor.

[0020] In a preferred embodiment of this application, the inlet guide slope section 3 and the boundary layer discharge pipe 5 are connected to form an outwardly protruding structure, and the shape of the tongue plate 6 is adapted to the protruding structure, thereby reducing the airflow of the boundary layer.

[0021] In some embodiments of this application, a lip 7 is provided at the upper (or outer) front end of the engine intake pipe 4 for rectifying the intake airflow.

[0022] In this application, engine 2 is a jet engine.

[0023] During flight, when the airflow upstream of the engine intake duct 4 flows into the embedded air intake along the inlet guide slope section 3, the airflow is divided into two by the tongue plate 6. The low-energy boundary layer airflow below the tongue plate 6 enters the boundary layer exhaust duct 5 and is eventually discharged to the outside of the fuselage 1, while the uniform airflow above the tongue plate 6 flows along the engine intake duct 4 to the engine 2.

[0024] In a preferred embodiment of this application, the reference position AA0 of the tongue plate 6 is determined as the design point based on the engine's maximum flow rate during high-speed cruise flight. This reference position is configured to effectively exclude low-energy boundary layer airflow while also ensuring a reasonable throat area for the engine intake duct 4. In this application, the area of ​​the engine intake duct 4 is typically significantly larger than the area of ​​the boundary layer exclusion duct 5, thereby ensuring sufficient air intake for the engine intake duct 4.

[0025] When the aircraft needs to operate the engine at low flow rates due to deceleration or descent, the tongue 6 is deflected upwards to position AA1, thereby increasing the inlet area of ​​the boundary layer exhaust duct 5 and decreasing the inlet area of ​​the engine intake duct 4. This allows more airflow to escape through the boundary layer exhaust duct 5, preventing flow separation caused by airflow obstruction in front of the embedded air intake. When the aircraft is flying at low speeds, the tongue 6 is deflected downwards to position AA2, thereby increasing the inlet area of ​​the engine intake duct 4 and improving low-speed performance. It is understandable that the specific deflection angle of the tongue 4 can be determined based on the actual flow field conditions of the embedded air intake.

[0026] The adjustable boundary layer diverter embedded air intake provided in this application controls the inlet area distribution of the boundary layer exhaust duct and the engine intake duct by adjusting the position of the tongue plate. This allows the embedded air intake to maintain good aerodynamic performance over a wide range of flight Mach numbers and intake flow rates, expanding the application range of the air intake. The solution in this application is simple, with few moving parts and a simple structure, and does not affect the main structure and shape of the air intake.

[0027] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A buried inlet structure with an adjustable boundary layer fence, characterized by, The application relates to a kind of aircrafts, comprising: A fuselage (1) and an engine (2) located inside the fuselage (1), the upper surface of the fuselage (1) is provided with an inlet guide slope section (3), the inlet guide slope section (3) is inclined to the downside, so as to form a recessed embedded air inlet at the inlet guide slope section (3), the inside of the fuselage (1) at the rear side of the inlet guide slope section (3) is provided with an engine air inlet pipe (4) and a boundary layer removal pipe (5), the engine air inlet pipe (4) is connected to the embedded air inlet and the engine (2), for guiding the airflow of the embedded air inlet into the engine (2), the boundary layer removal pipe (5) is connected to the embedded air inlet and the lower side of the fuselage (1), for guiding the airflow of the embedded air inlet out of the inside of the fuselage (1); Wherein, a controllable deflection tongue plate (6) is provided at the joint part of the engine air inlet pipe (4) and the boundary layer removal pipe (5), by controlling the deflection of the tongue plate (6), the area ratio or flow ratio of the airflow at the embedded air inlet to the engine air inlet pipe (4) and the boundary layer removal pipe (5) is adjusted.

2. The buried inlet structure of an adjustable boundary layer channel according to claim 1, wherein The reference position of the tongue plate (6) is determined according to the design point of the engine maximum flow state when the aircraft is in high-speed cruise flight.

3. The flush-mounted inlet structure of a variable boundary-layer channel according to claim 1, wherein The tongue plate (6) is installed at the joint part of the engine air inlet pipe (4) and the boundary layer removal pipe (5) through a control device, and the control device comprises a rudder.

4. The structure of claim 1, wherein the thickness of the adjustable boundary layer slot is varied by varying the thickness of the slot. The connection part of the inlet guide slope section (3) and the boundary layer removal pipe (5) forms an outward protruding structure, and the shape of the tongue plate (6) is adapted to the outward protruding structure.

5. The flush-mounted inlet structure of a variable boundary-layer channel according to claim 1, wherein The front end of the outside of the engine air inlet pipe (4) is provided with a lip (7).

6. The buried inlet structure of a variable boundary layer channel according to claim 1, wherein The engine (2) is a jet engine.

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