RU2249545C1 - Method of preparation of aircraft for takeoff from flying-off apron of aircraft carrier - Google Patents

Abstract

FIELD: marine aviation; preparation of aircraft for takeoff from flying-off position of aircraft carrier.

SUBSTANCE: proposed method includes arresting the aircraft on flying-off apron, mounting the gas-deflecting shield at angle of 50-70° relative to surface of deck, attaining the "maximum boost" mode of engine, checking the aircraft readiness for takeoff, transmitting the information on readiness to fly off and releasing the lock. If aircraft is equipped with engines provided with swivel nozzle, swivel nozzle control mode shall be switched-on after arresting the aircraft. Then, nozzle is deflected upward through angle of 14-18° which is maintained for 0.7-1 s at "maximum boost" mode and is reduced to 6-9° in 6-10 s and is kept in this position for 6-8 s. At the moment of releasing the lock, nozzle is returned to neutral position. Gas jet of engine is reflected from gas deflecting shield due to reduction of reverse flow of gases sucked by air intake.

EFFECT: enhanced efficiency and reliability.

2 dwg

Description

The invention relates to the field of naval aviation and, in particular, to methods for preparing an aircraft for take-off from the starting position of an aircraft carrier ship.

A known method of preparing the aircraft for take-off from the starting position of the aircraft carrier, including locking the aircraft at the launch site of the aircraft carrier, installing a gas-reflecting shield of the aircraft carrier at an angle of 60 degrees relative to the surface of its deck, bringing the aircraft engines to full boost, monitoring the aircraft’s readiness for take-off , transmitting a message about this readiness and removing the airplane stopper [1].

In the process of preparing the aircraft for takeoff, the interaction of the gas stream exiting the engine nozzle with a flat gas shield installed at an angle of 60 ° to the surface of the deck of the aircraft carrier leads to a gas flow spreading over the entire surface of the shield with the formation of side and reverse flows. The return gas stream flowing under the fuselage spreads far ahead and is sucked in by the air intake, leading to unstable operation of the aircraft engines. At the same time, in the “fast and the furious” mode, as a result of hot gases entering the power plant inlets, there were cases of loss of gas-dynamic stability of the engines.

A decrease in the angle of inclination of the shield to the surface of the deck leads to a decrease in the angle of leakage of jet jets onto the shield, as a result of which the mass and speed in the reverse flow towards the starting aircraft are reduced. So, for example, when the angle of inclination of the shield is up to 40 degrees, the reverse flow rate is reduced by three times compared with the installation at an angle of 60 degrees.

At the same time, a decrease in the angle of inclination of the gas reflecting shield to the deck surface leads to the formation of a low pressure area behind the shield, into which hot exhaust gases rush, as a result of which a separation zone with a strong vortex flow and high temperature forms behind the shield. The temperature in the air intake of the aircraft, standing behind the shield, inclined at an angle of 40 degrees, compared with the installation angle of 60 degrees increases four times and significantly exceeds the permissible norms.

The objective of the invention is to ensure stable operation of the engine in the process of preparing the aircraft for take-off from the starting position of the aircraft carrier, by reducing the reverse gas flow, without the formation of a separation zone behind the gas shield, with a strong vortex flow and high temperature.

The problem is solved in that in the method of preparing the aircraft for take-off from the launch position of the aircraft carrier, including locking the aircraft on the launch platform of the aircraft carrier, setting the gas reflector shield of the aircraft carrier at an angle of 50-70 degrees relative to the surface of its deck, bringing the aircraft engines to the full boost mode ”, Monitoring the readiness of the aircraft for takeoff, transmitting a message about this readiness and removing the stopper of the aircraft, for an aircraft equipped with engines with a rotary nozzle, after locking it in they turn on the control mode of the rotary nozzle, divert the nozzle upward at an angle of 14-18 degrees, maintain it in the full afterburner mode for 0.7-1 seconds, after which they reduce the nozzle deflection angle to 6-9 degrees for 6-10 seconds and maintain it is in this position for 6-8 seconds, and at the time of removal of the stopper of the aircraft, the nozzle is returned to the neutral position.

The inclusion of the control mode of the rotary nozzle allows the deflection of the rotary nozzle of the aircraft engine.

Deviation of the nozzle up to an angle in the range of 14-18 degrees and keeping it in full fast and furious mode for 0.7-1 seconds, followed by a decrease in the nozzle tilt angle to 6-9 degrees for 6-10 seconds and keeping it in this position for for 6-8 seconds provides a decrease in the angle of leakage of a gas stream onto a gas-reflecting shield.

The dependence of the change in the angle of the leakage of the jet on the gas shield over time t is determined by the expression

α (t) = 60 ° -β (t), where

t is the time change in the interval from the moment the engine enters the “full fast and furious” mode until the airplane stopper is removed;

β is the angle of deviation of the engine nozzle relative to the vertical plane.

A decrease in the angle α (t) by β (t) will lead to a decrease in the intensity and length of the reverse gas flow, while the temperature in the air intake of the aircraft behind the shield will not exceed the permissible norms. In reality, on modern aircraft, the maximum deflection angle of the engine nozzle lies within 14-18 degrees.

The time spent by the nozzle in a deviated position, depending on the angle, is determined by the permissible level of heating of the nozzle elements. The larger the angle of deviation of the nozzle, the shorter the time spent on this angle. So, in the “fast and the furious” mode, the time spent by the nozzle at the maximum angle should not exceed 1 second, and when the angle of the nozzle is reduced to 6–9 degrees, it increases to 6–8 seconds.

The time to decrease the nozzle deflection angle from 14-18 degrees to 6-9 degrees within 6-10 seconds is determined by the technical capabilities of the nozzle control system.

The invention is illustrated graphically, in which Fig. 1 shows a diagram of the flow of a gas jet of an engine reflected from a gas shield, and Fig. 2 shows a cyclogram of a change in the nozzle deflection angle in the time interval for preparing the aircraft for take-off.

The presented diagram clearly shows that the gas flow coming out of the nozzle 1 of the aircraft engine, reflected from the gas reflection shield 2, installed at an angle of 60 degrees to the surface of the deck 3 of the aircraft carrier, is divided into a reverse flow passing under the fuselage 4 of the aircraft, and the fan flow deflected up from the shield 2.

The method of preparing the aircraft for take-off from the starting position is carried out in the following sequence.

The aircraft in the “small gas” mode is distilled from the technical position to the starting one, where it is locked using the delay device. The gas reflection shield is raised at an angle of 50-70 degrees with respect to the deck of the aircraft carrier. The pilot includes a control mode deviation of the rotary nozzle. The rotary nozzle is deflected by an angle of 14-18 degrees and the engine is brought to the “full boost” mode, keeping the nozzle in this mode for 0.7-1 seconds, after which the nozzle deflection angle is reduced to 6-9 degrees for 6-10 seconds and maintain it in this position for 6-8 seconds. Next, they monitor the readiness for take-off, and in case of readiness send a message about it. The plane is removed from the stopper, while returning the nozzle to the neutral position.

In a specific example, with a maximum nozzle deflection angle of 14 degrees, the nozzle deflection in the time interval for preparing the aircraft for take-off is performed in accordance with the sequence diagram shown in FIG.

The invention is possible due to the installation on the Su-33 aircraft of AL-31FP engines with a rotary jet nozzle and allowing control of the thrust vector. Currently, a ship combat training aircraft (KUB-1) with AL-31FP engines is undergoing flight tests.

The invention allows for the stable operation of aircraft engines in the process of preparing for take-off from the starting position of an aircraft carrier by reducing the return gas flow, while eliminating the excess of temperature behind the gas reflection shield above acceptable standards.

Sources of information

1. A. Fomin “Su-27. The history of the fighter. ” RA Intervestnik, Moscow, 1990

Claims (1)

A method of preparing an aircraft for take-off from the launch site of an aircraft carrier, including locking the aircraft at the launch platform of an aircraft carrier, installing a gas reflection shield at an angle of 50-70 ° relative to the surface of the deck of an aircraft carrier, bringing the aircraft engines to full boost, monitoring readiness for take-off, transmitting a message about the readiness for take-off and removing the stopper of the aircraft, characterized in that on an aircraft equipped with engines with a rotary nozzle, after locking the aircraft, the control mode is activated I swivel the nozzle, deflect the nozzle upward at an angle of 14-18 °, maintain it in the "fast and the furious" mode for 0.7-1 s, then reduce the nozzle deflection angle to 6-9 ° for 6-10 s and maintain it is in this position for 6-8 s, and at the time of removal of the stopper of the aircraft, the nozzle is returned to the neutral position.

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