Overall optimization design of high temperature components cooling coefficient for lower infrared turbofan engine

Abstract

A novel aero-engine overall design method which optimizes the thrust, fuel consumption and infrared radiation and other importance performance comprehensive is proposed to reduce engine infrared radiation. A prediction model for infrared radiation intensity of engine exhaust system is established. The cooling air flow for high temperature components is chosen as optimization design variables. This overall design method not only considers the restriction of engine design limit, but also takes the change of engine performance parameters into account. The simulations of cooling effects of different components such as high pressure turbine, low pressure turbine, cooling center cone, inner wall of the expansion section are conducted. And the simulations show that the cooling effect of inner wall of the expansion section is the best, the second is cooling the center cone. The overall optimization design simulations show that the total infrared radiation intensity of the exhaust system is reduced by 51.38%. And the action distance of the infrared detector is reduced by 40.49%, which has significant infrared suppression effect.