关键词: 定向流喷嘴旋流增强器, 数值模拟, 发动机唇口防冰, 换热

Abstract: This study addresses the anti-icing issue of the lip of a high-bypass turbofan engine. A numerical simulation method is employed to compare and analyze the heating performance of two bleed air anti-icing methods: the Directed Flow Nozzle Swirl Enhancer (DFNSE) and the traditional piccolo tube. The influence of key geometric parameters of the DFNSE (twist angle, number of flow channels, and contraction-expansion ratio of the annular flow passage) on the anti-icing effect is systematically investigated. The results indicate that, under identical bleed air conditions, the DFNSE exhibits a higher average temperature on the outer skin, lower bleed air pressure, and reduced thermal accumulation compared to the piccolo tube, resulting in a less-er impact on engine performance. Through numerical simulations of heat transfer effects under varying structural parameters, it is found that the twist angle, number of flow channels, and contraction-expansion ratio have significant nonlinear effects on heating uniformity and system energy consumption. An optimal combination exists, enabling both efficient heating and low-energy operation. Furthermore, the study pro-poses a comprehensive evaluation metric, the "heating quality coefficient" (ηq), which confirms that the DFNSE outperforms the traditional piccolo tube in terms of heating efficiency, temperature uniformity, and system economy. This coefficient provides a quantitative indicator for evaluating the performance of anti-icing systems. The research offers theoretical foundations and engineering guidance for the optimal de-sign of anti-icing systems for aero-engine lips.

Key words: Directed flow nozzle swirl enhancer, numerical simulation, aeroengine lip anti-icing, heat transfer.