锯齿结构对带襟翼的NACA2418翼型的气动及噪声影响

Study on the Aerodynamic and Noise Effects of Serrated Structure on NACA2418 Flap Air-foil

在低雷诺数(1.4 × 105)下,基于NACA2418翼型,通过IDDES和FW-H方法对平板襟翼翼型(PGF)和锯齿平板襟翼翼型(SGF)的气动性能及噪声特性进行了数值模拟,并探讨了涡旋结构对流场和声场的影响机理。结果表明,在所研究的攻角下,相比于PGF,SGF可以进一步提高升阻比,并降低远场噪声。锯齿结构在未失速和深度失速情况下都可以控制低速区范围,减少翼型表面的涡团,从而获得了更好的气动性能和更低的噪声。与PGF相比,SGF的升阻比在大多数攻角下(3˚~20˚)更大,最大升阻比提高了9.27%。与PGF相比,α = 6˚时,SGF的OASPL降低了6.9 dB;α = 20˚时,SGF的OASPL降低了3.8 dB。

At low Reynolds numbers (1.4 × 105), based on the NACA2418 airfoil, numerical simulations were conducted using IDDES and FW-H methods to investigate the aerodynamic performance and noise characteristics of the Plate Gurney Flap airfoil (PGF) and Serrated Gurney Flap airfoil (SGF), and the influence mechanism of vortex structure on the flow field and sound field was explored. The results indicate that at the studied angle of attack, SGF can further improve the lift-to-drag ratio and reduce far-field noise compared to PGF. The serrated structure can control the low-speed range in both non stall and deep stall situations, reduce vortex clusters on the airfoil surface, and thus achieve better aerodynamic performance and lower noise. Compared with PGF, SGF has a higher lift-to-drag ratio at most angles of attack (3˚~20˚), with a maximum increase of 9.27%. Compared to PGF, at α = 6˚, the OASPL of SGF decreased by 6.9 dB;At α = 20˚, the OASPL of SGF decreased by 3.8 dB.