A dual-channel buried air intake

Abstract

The present invention discloses a dual-channel embedded air intake duct. The dual-channel embedded air intake duct comprises an air intake duct arranged on an aircraft body (7), an inner channel (1) being arranged in the air intake duct along its axis, a discharge channel (2) being formed between the inner wall of the air intake duct and the outer wall of the inner channel (1); the air intakes of the inner channel (1) and the discharge channel (2) are flush with the aircraft body (7). The present invention solves the technical problems of the current embedded air intake duct having a low total pressure recovery coefficient and a large outlet flow field distortion.

Description

Technical Field

[0001] The invention belongs to the technical field of aircraft air inlet design, and in particular relates to a dual-channel embedded air inlet. Background Art

[0002] The embedded air inlet is an air inlet with no protruding parts and the inlet is buried in the aircraft. The embedded air inlet has a small frontal area and a small radar scattering area, so its frontal resistance is small and its stealth performance is good. At the same time, the embedded air inlet is integrated with the missile body / fuselage, which effectively reduces the size of the aircraft and is conducive to the placement, carrying and box-type launch of the aircraft. However, since the inlet of the embedded air inlet is completely placed in the boundary layer of the missile body / fuselage, it is impossible to use the incoming flow ram pressure to inhale air. It only relies on the pressure gradient of the front lip perpendicular to the incoming flow direction and the vortex generated by the side edges to inhale air. Therefore, the embedded air inlet will inhale a large amount of boundary layer. At the same time, the side edge vortex will cause a large airflow mixing loss, which makes the total pressure loss of the embedded air inlet and the outlet cross-sectional flow field distortion larger. Summary of the invention

[0003] The purpose of the present invention is to provide a dual-channel embedded air intake duct. The present invention solves the technical problems of low total pressure recovery coefficient and large outlet flow field distortion of the current embedded air intake duct.

[0004] The technical solution of the present invention is: a dual-channel embedded air inlet, including an air inlet channel arranged on the aircraft body, an inner channel is arranged in the air inlet channel along its axis, and a discharge channel is formed between the inner wall of the air inlet channel and the outer wall of the inner channel; the air inlets of the inner channel and the discharge channel are flush with the aircraft body.

[0005] In the aforementioned dual-channel embedded air intake duct, a symmetrical surface connecting support plate is provided in the discharge channel to fix the inner channel.

[0006] In the aforementioned dual-channel embedded air intake duct, the rear lips of the inner channel and the discharge channel are connected via a rear lip connecting support plate.

[0007] In the aforementioned dual-channel embedded air intake duct, the width h of the rear lip connecting support plate is smaller than the width H of the rear lip of the inner channel.

[0008] In the aforementioned dual-channel embedded air intake duct, the front lip of the inner channel is provided with a guide slope I.

[0009] In the aforementioned dual-channel embedded air intake duct, the front lip of the discharge channel is provided with a guide slope II.

[0010] In the aforementioned dual-channel buried air intake duct, the ratio of the mouth surface area of ​​the discharge channel and the inner channel is 1 / 10 to 1 / 8.

[0011] In the aforementioned dual-channel embedded air intake duct, the discharge channel and the front lip of the inner channel are in an outwardly convex arc structure.

[0012] The advantages of the present invention are as follows: the dual-channel embedded air intake of the present invention is also provided with a discharge channel in addition to the inner channel. The low-energy flow along the incoming flow direction flows through the front lip of the discharge channel and then directly enters the discharge channel for discharge, while the high-energy fluid in the mainstream area enters the inner channel; at the same time, the vortex generated by the side edges of the discharge channel and the boundary layer sucked in flows through the side edges of the discharge channel and then enters the discharge channel for discharge, while the vortex generated by the side edges of the inner channel develops downstream and flows through the rear lip of the inner channel and then enters the discharge channel for discharge or is directly discharged. That is, the present invention reduces the low-energy flow in the boundary layer flowing into the embedded air intake, improves the quality of the airflow sucked into the embedded air intake, thereby effectively improving the total pressure recovery coefficient of the embedded air intake and reducing the outlet distortion index.

[0013] Simulation calculation results show that, compared with the conventional embedded air inlet, the dual-channel embedded air inlet of the present invention has an inlet total pressure recovery coefficient increased from 0.92 to 0.94, and a comprehensive distortion index reduced from 2.75% to 2.2% under the conditions of an inlet Mach number of 0.60, an inlet attack angle of 2°, and an inlet outlet Mach number of 0.32.

[0014] At the same time, the combustion in the engine combustion chamber produces high-temperature and high-pressure combustion gas, which causes the temperature of the space formed by the engine surface and the tail cabin to be higher. Aircraft often arrange components at this position, and some components have operating temperature limitations. Therefore, in this case, it is necessary to strictly limit the temperature in the tail cabin. The dual-channel embedded air inlet of the present invention can discharge the vortex low-energy flow discharged by the discharge channel to the tail cabin, cool the space formed by the engine surface and the tail cabin, reduce the operating temperature of components with temperature limitations, and ensure their stable and normal operation.

[0015] In addition, the dual-channel embedded air inlet of the present invention can be used in conjunction with an ejector nozzle, that is, the ejector nozzle is installed at the tail nozzle of the engine, and the vortex low-energy flow discharged from the discharge channel can flow to the tail cabin and further to the ejector nozzle, which can also increase thrust and reduce infrared radiation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the present invention;

[0017] Figure 2 It is a cross-sectional view of the present invention.

[0018] Figure numerals: 1-inner channel, 2-discharge channel, 3-rear lip connecting support plate, 4-symmetry surface connecting support plate, 5-guide slope I, 6-discharge channel side edge, 7-aircraft body, 8-guide slope II. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0020] Embodiment 1. A dual-channel embedded air intake, comprising: Figure 1-2 As shown, it includes an air intake channel arranged on the aircraft body 7, an inner channel 1 is arranged in the air intake channel along its axis, and a discharge channel 2 is formed between the inner wall of the air intake channel and the outer wall of the inner channel 1; the air intake ports of the inner channel 1 and the discharge channel 2 are flush with the aircraft body 7.

[0021] A symmetrical surface connecting support plate 4 is arranged in the aforementioned discharge channel 2 for fixing the inner channel 1 .

[0022] The inner channel 1 and the rear lip of the discharge channel 2 are connected via a rear lip connecting support plate 3 .

[0023] The width h of the aforementioned rear lip connecting support plate 3 is smaller than the width H of the rear lip of the inner channel 1 .

[0024] The front lip of the aforementioned inner channel 1 is provided with a flow guide slope Ⅰ5.

[0025] The front lip of the aforementioned discharge channel 2 is provided with a guide slope II8.

[0026] The ratio of the opening surface area of ​​the aforementioned discharge channel 2 to that of the inner channel 1 is 1 / 10 to 1 / 8.

[0027] The aforementioned discharge channel 2 and the front lip of the inner channel 1 are in an outwardly convex arc structure.

[0028] The low-energy flow along the incoming flow direction flows through the front lip of the discharge channel and directly enters the discharge channel for discharge, while the high-energy fluid in the mainstream area enters the inner channel; the vortex generated by the side edge 6 of the discharge channel and its entrained boundary layer flows through the side edge 6 of the discharge channel and enters the discharge channel for discharge, and the vortex generated by the side edge of the inner channel develops downstream and flows through the rear lip of the inner channel to enter the discharge channel for discharge or is directly discharged from the body.

Claims

1. A dual-channel embedded air intake, characterized in that: It comprises an air intake passage arranged on an aircraft body (7), wherein an inner passage (1) is arranged in the air intake passage along its axis, and a discharge passage (2) is formed between the inner wall of the air intake passage and the outer wall of the inner passage (1); the air intakes of the inner passage (1) and the discharge passage (2) are flush with the aircraft body (7); The rear lips of the inner channel (1) and the discharge channel (2) are connected via a rear lip connecting support plate (3); The width h of the rear lip connecting support plate (3) is smaller than the width H of the rear lip of the inner channel (1); The ratio of the opening area of ​​the discharge channel (2) to that of the inner channel (1) is 1 / 10 to 1 / 8; The front lips of the discharge channel (2) and the inner channel (1) are in an outwardly convex arc-shaped structure.

2. The dual-channel embedded air intake according to claim 1, characterized in that: A symmetrical surface connecting support plate (4) is provided in the discharge channel (2) and is used to fix the inner channel (1).

3. The dual-channel embedded air intake according to claim 1, characterized in that: The front lip of the inner channel (1) is provided with a flow guide slope I (5).

4. The dual-channel embedded air intake according to claim 1, characterized in that: The front lip of the discharge channel (2) is provided with a flow guide slope II (8).

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