Pneumatic and infrared comprehensive design method for low-detectability large-curvature spray pipe

Abstract

The invention belongs to the field of aero-engines, and particularly relates to a pneumatic and infrared comprehensive design method for a low-detectable large-curvature spray pipe, which comprises the following steps: S1, selecting a characteristic section of the spray pipe; determining pneumatic profile parameters based on a nozzle pneumatic flow path design method; s2, obtaining a first geometric shielding profile meeting a preset infrared radiation suppression requirement on the basis of a rear-view shielding design requirement; s3, the geometric shielding molded surface is corrected through a secondary flow injection cooling means, a second geometric shielding molded surface is obtained, and meanwhile a first gas film molded surface is obtained; and S4, engine outer culvert air entraining parameters are obtained, the first air film molded surface is corrected through the engine outer culvert air entraining parameters, a second air film molded surface is obtained, and the infrared suppression performance of the spray pipe is improved by reducing the curvature of the spray pipe, reducing the thrust performance loss of the spray pipe and reducing the wall temperature of the spray pipe.

Description

technical field [0001] The application belongs to the field of aero-engines, and in particular relates to a low-detectable and large-curvature nozzle integrated aerodynamic and infrared design method. Background technique [0002] When designing an exhaust system, aerodynamic design goals and infrared design goals are often contradictory. In order to balance the two, when designing the exhaust system, it is necessary to minimize the change of the airflow direction of the exhaust system, that is, to minimize the curvature of the exhaust system, thereby reducing the local loss of airflow along the way. The smaller curvature of the exhaust system has a limited shielding effect on the high-temperature components at the front end, and the suppression effect on the infrared radiation intensity is small. The exhaust system with larger curvature has obvious effect on the inhibition of infrared radiation intensity, but the negative effect on the aerodynamic performance is also obvio...

AI Technical Summary

Problems solved by technology

[0004] The aerodynamic and infrared performance are only related to the geometric parameters. A relatively simple correlation model will inevitably lead to the sacrifice of a part of the aerodynamic performance or infrared radiation performance, and it is impossible to fully balance the two performances.

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