Combined subsonic air intake device of aircraft

Abstract

The invention belongs to the technical field of aircraft air intake ducts and discloses a combined subsonic air intake device of an aircraft. The device comprises an embedded air intake duct, an externally-hung air intake structure and an automatically-separated connection mechanism. The embedded air intake duct comprises a fixed air intake passage and a fixed flange plate. The externally-hung air intake structure comprises a jettisonable air intake passage, a front fairing, a rear fairing and a jettisonable flange plate. The automatically-separated connection mechanism comprises an explosive bolt and a connecting sheet. The jettisonable air intake passage, the front fairing and the rear fairing are fixed to the jettisonable flange plate through connecting pieces, the jettisonable flange plate is fixed to an inlet of the embedded air intake duct on the aircraft through the explosive bolt and the connecting sheet, and an airflow outlet of the externally-hung air intake structure is matched with an airflow inlet of the embedded air intake duct. According to the device, flow distortion is good, engine thrust loss is reduced, and the flying ability of the aircraft is guaranteed; the externally-hung air intake structure is separated from the aircraft at the tail section of the aircraft, and therefore the stealth defense penetration ability of the aircraft is guaranteed.

Description

technical field [0001] The invention belongs to the technical field of aircraft air intakes, and more specifically relates to an aircraft subsonic air intake device. Background technique [0002] The subsonic air inlet can be equipped on the aircraft whose flight speed is sub-transonic, as the air intake device of the air-breathing engine. In order to reduce the flight resistance of the aircraft, the engine is generally built-in and installed inside the aircraft. Correspondingly, the subsonic air inlet has two forms: S-shaped air inlet and buried air inlet. [0003] Early aircraft mostly used S-shaped inlets. The S-shaped inlets can use the speed of airflow to pressurize. The total pressure recovery coefficient of the inlet outlet is relatively high. Generally, the total pressure recovery coefficient σ is above 0.98. According to theoretical analysis According to the statistical results of the test, an increase in the total pressure recovery coefficient of the inlet port by...

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Problems solved by technology

[0006] However, it is difficult for the buried air intake to take advantage of the speed ramming effect of the airflow, so the total pressure recovery capability of the air intake is low, and the total pressure recovery coefficient σ at the outlet of the air intake is about 0.92; at the same time, the outlet of the buried air intake The flow field distortion of the engine is also poor, which has a great impact on the engine's potential and stable work

[0007] Some long-range, radar-stealth aircraft flying at high subsonic speeds need to use buried air inlets to ensure the stealth performance of the entire fuselage RCS when the aircraft approaches the target. Stealth performance requirements are not high, but the total pressure recovery coefficient σ of the buried air inlet is low, and the flow field distortion at the outlet of the air inlet is relatively large, which will have a great impact on the flight range of the aircraft

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