Spray pipe and aircraft afterbody slit exhaust cooling device

Abstract

The invention belongs to the technical field of engine design, and particularly relates to a spray pipe and an aircraft afterbody slit exhaust cooling device. The device comprises a gas collecting cavity communicated with an engine outer culvert, the gas collecting cavity is located between the side wall of a spray pipe and the inner wall face and the outer wall face of a throat adjusting piece, the gas collecting cavity is provided with a side wall exhaust slit (1) at the rear end of the side wall of the spray pipe, the side wall exhaust slit (1) is formed in the front side of an aircraft afterbody or a tail cone (3), and exhaust of the side wall exhaust slit (1) is roughly parallel to the jet flow direction of the spray pipe; the air collecting cavity is provided with an expansion section exhaust slit (5) on the inner wall surface of the expansion section of the throat adjusting sheet of the spray pipe, and the exhaust direction of the expansion section exhaust slit (5) is approximately parallel to the airflow flowing direction of the near wall surface of the expansion section adjusting sheet of the spray pipe. The overall strength of the cooling mechanism is improved, the machining difficulty and the machining cost are reduced, the cooling range of the spray pipe and the aircraft afterbody is larger, the cooling effect is better, and meanwhile the backward radar stealth and infrared stealth effects of an aircraft can be better improved.

Description

technical field [0001] The application belongs to the technical field of engine design, and in particular relates to a nozzle and an aircraft rear body slit exhaust cooling device. Background technique [0002] After adopting rectangular nozzles such as binary thrust vectoring nozzles and unilateral expansion nozzles, the aircraft generally adopts a pointed tail vertebra structure, so that the aircraft as a whole meets the requirements of supersonic speed area ratio and reduces the pressure difference resistance of the rear body. It generally accommodates equipment such as drogue parachute and backward detection. Because important equipment will be accommodated in the tail cone, and a large number of composite materials are used on the surface and the stealth coating is sprayed. The temperature resistance of composite materials and stealth coatings is poor, so higher requirements are put forward for the thermal protection ability of the rear body of the aircraft. [0003] T...

AI Technical Summary

Problems solved by technology

[0005] 1) A large number of holes in the heat shield on the side wall of the engine nozzle will greatly increase the radar reflection intensity of the nozzle and reduce the stealth effect of the binary nozzle. At the same time, a large number of holes on the surface of the heat shield will reduce the strength of the heat shield, and The aerodynamic stress generated by the pressure difference inside and outside the heat shield and the thermal stress generated by the high-temperature jet will concentrate on the opening position, which will easily cause damage to the heat shield. In order to meet the strength requirements of the heat shield, the thickness of the heat shield must be increased. Increase nozzle weight;

[0006] 2) A large number of holes are opened on the heat shield, and the process is complicated, which will increase the processing difficulty and cost, and the performance and machinability of the material are high, and the range of available materials is small;

[0007] 3) In film cooling, the incident angle of cold air cannot be parallel to the wall surface, and the mixing effect with high-temperature jet flow is strong, and the wall surface is not easy to be completely covered by cold air, and the cooling effect is poor

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