Numerical Study on Film Effectiveness and Heat Transfer Characteristics of Aero-Engine Nose Cone With Hot Air Film

When the aircraft works in an environment containing supercooled water droplets, it is easy to cause the engine inlet nose cone on the windward side to freeze, which not only affects the performance of the engine, but also leads to flight accidents. Therefore, it is necessary to research the anti-icing technology of aero-engine nose cone components. At present, the air intake cone of the aircraft mainly forms a thermal anti-icing system by means of hot film anti-icing and heating impingement anti-icing. In this paper, the effects of blowing ratio, film hole pitch, hole shape and film hole arrangement method on film heating effectiveness and heat transfer characteristics are studied by numerical simulation methods for the hot film anti-icing system of the nose cone. The results show that with the increase of the blowing ratio, the film heating effectiveness in the downstream area quickly decreases first and then increases, and the range of change aggrandizes. Under the given condition, as the pitch between the film holes decreases, the area covered by the film extends, and the heating effectiveness improves significantly. In the case of high blowing ratio, the advantage of film heating effectiveness of waist-shaped film hole is more apparent. The laterally-averaged film heating effectiveness of the staggered film holes is much higher than that of the aligned film holes. For the characteristics of film heat transfer, the hole pitch and hole shape has little effect on the heat transfer characteristics at low blowing ratio. In the case of high blowing ratio, the heat transfer effect will be greatly weakened when the hole pitch is increased, moreover the heat transfer efficiency of the waist-shaped hole is better. In the region near the exit of the secondary row film hole, the heat transfer characteristics of the staggered structure is stronger than that in the aligned structure. In addition, it is found that the high heat transfer region for staggered arrangement shows W–shaped.