This work addresses the use of a Cross-Flow Fan (CFF) technology as a high-lift device for Extremely Short Take-off and Landing (ESTOL) aircraft. The particular objective of the current paper is investigation of the acoustics of a conceptual airfoil design with embedded CFF used as an active circulation control (ACC) device. Comparative DES simulations are performed for 3 cases including a baseline NACA 65(3)-221 airfoil with the Fowler flap, and the same airfoils with embedded stationary and rotating CFF. Ffowcs Williams Hawkings method is employed to calculate noise in the far field. Results indicate a significant increase (up to 45 dB compared to the baseline) in the far-field acoustic SPL levels for the airfoil with embedded rotating fan, with a gain of 447c in the lift coefficient. The acoustic signature indicates a superposition of several acoustic sources dominated by the noise from the developed suction-side wall-jet vortical structures scattering at the flap and trailing edge of the fan-wing airfoil.
展开▼
机译：这项工作解决了使用横流风扇（CFF）技术作为极短距起降（ESTOL）飞机的高升力设备的问题。本文的特定目标是研究概念性机翼设计的声学效果，该概念机翼设计采用嵌入式CFF作为主动循环控制（ACC）装置。对3种情况进行了比较DES仿真，包括带有Fowler襟翼的基线NACA 65（3）-221机翼，以及带有嵌入式固定和旋转CFF的相同机翼。 Ffowcs Williams Hawkings方法用于计算远场噪声。结果表明，带有嵌入式旋转风扇的机翼的远场声学SPL级别显着提高（与基线相比，最高45 dB），升力系数提高447c。声学特征表明几个声源的叠加，这些声源主要来自散布在襟翼和机翼后缘的发达的吸力侧壁射流涡流结构产生的噪声。
展开▼
