Most of the flow separation control devices used in the aircraft wing are effective at high angles of attack, and adversely affect the performance of the wing at low angles of attack. In flight mission, the cruise phase takes major portion than the take-off and landing. Therefore, the flow separation control devices installed on wing may reduce the performance of the aircraft in total flight mission. A bio-inspired passive flow control method is used by introducing leading edge modification. The leading edge modification inspired by the cetacean species (Porpoise) has been analyzed on NACA2412 and NACA66215 airfoils at different subsonic speed using 2D analysis. The effect of the spanwise location and extent of these leading edge modifications is analyzed using a three-dimensional numerical investigation. The porpoise nose design (shorter length and medium depth i.e. depth — 2.25 % of chord, nose length — 0.75 % chord, and nose diameter — 2 % chord) delay the flow separation and improves the aerodynamic efficiency up to the critical Mach number. After critical Mach number, the shock wave formation affects the porpoise nose performance and shows similar flow behavior as base airfoil. A finite wing with a porpoise nose design of full spanwise length showed the better aerodynamic efficiency than base wing model. This rigid design improves aerodynamic performance of a wing without major structural modification.

飞机机翼中使用的气流分离控制装置大多在大迎角时有效，在小迎角时对机翼性能产生不利影响。在飞行任务中，巡航阶段比起飞和着陆阶段占主要部分。因此，安装在机翼上的分流控制装置可能会降低飞机在全飞行任务中的性能。通过引入前沿修改来使用仿生被动流量控制方法。已使用二维分析在 NACA2412 和 NACA66215 机翼上以不同的亚音速分析了受鲸类物种（江豚）启发的前缘修改。使用三维数值调查分析了这些前缘修改的展向位置和范围的影响。海豚鼻设计（较短的长度和中等深度，即深度 — 弦长的 2.25%，鼻长 — 弦的 0.75%，鼻直径 — 弦的 2%）延迟了流动分离并提高了空气动力学效率，直至达到临界马赫数。在临界马赫数之后，激波的形成会影响海豚鼻的性能，并显示出与基础翼型相似的流动行为。具有全展向长度的海豚鼻设计的有限机翼显示出比基础机翼模型更好的空气动力学效率。这种刚性设计提高了机翼的空气动力学性能，而无需进行重大的结构修改。激波的形成会影响海豚鼻的性能，并显示出与基础翼型相似的流动行为。具有全展向长度的海豚鼻设计的有限机翼显示出比基础机翼模型更好的空气动力学效率。这种刚性设计提高了机翼的空气动力学性能，而无需进行重大的结构修改。激波的形成会影响海豚鼻的性能，并显示出与基础翼型相似的流动行为。具有全展向长度的海豚鼻设计的有限机翼显示出比基础机翼模型更好的空气动力学效率。这种刚性设计提高了机翼的空气动力学性能，而无需进行重大的结构修改。