关键词: 定向流喷嘴旋流增强器, 航空发动机唇口, 防冰, 换热, 流固耦合, 加热质量系数

Abstract:

To address the anti-icing issue of the lip of a high-bypass-ratio 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 DFNSE （twist angle， number of flow passage， and contraction-expansion ratio of the annular flow passage） on anti-icing effects 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 less heat accumulation， compared to the piccolo tube， resulting in a lesser impact on engine performance. Through investigation of heat transfer effects under varying structural parameters， it is found that the twist angle， number of flow passage， 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-consumption operation. Furthermore， the study proposes a comprehensive evaluation metric， the “heating quality coefficient”， 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 the performance evaluation of the anti-icing system. The research conclusions can serve as a theoretical basis and engineering guidance for the optimal design of the aero-engine lip anti-icing system

Key words: directed flow nozzle swirl enhancer, aero-engine lip, anti-icing, heat transfer, fluid-structure interaction, heating quality coefficient