Aerodynamic performance and flow structure analysis of a swallow–inspired NACA2415 airfoil
Bioinspiration and Biomimetics, cilt.21, sa.3, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 21 Sayı: 3
- Basım Tarihi: 2026
- Doi Numarası: 10.1088/1748-3190/ae6210
- Dergi Adı: Bioinspiration and Biomimetics
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, Compendex, INSPEC, MEDLINE
- Anahtar Kelimeler: aerodynamic performance, bioinspired airfoil, smoke-wire visualization, surface oil visualization, swallow wing
- Ankara Yıldırım Beyazıt Üniversitesi Adresli: Evet
Özet
This study investigates the aerodynamic characteristics of a swallow-inspired wing based on a NACA 2415 airfoil at Reynolds numbers of 7.5 × 104 and 1.25 × 105 using experimental force measurements and flow-visualization techniques. The bioinspired wing model was designed according to the top-view geometry of a swallow wing and tested in a low-speed open-suction wind tunnel together with a rectangular wing of identical planform area and airfoil profile to provide a baseline comparison. Aerodynamic measurements were conducted over an angle-of-attack range between −6° and 24° to determine lift, drag and moment coefficients as well as aerodynamic efficiency. In addition to force measurements, smoke-wire and TiO2 based flow visualization techniques were used to examine the flow topology around the test models. The results show that the swallow-inspired wing exhibits improved aerodynamic performance compared with the rectangular configuration under both Reynolds number conditions. At Re= 1.25 × 105, the bioinspired wing achieved a maximum lift coefficient of 0.694 at an angle of attack of 9°, while the minimum drag coefficient was approximately 7.48 × 10−3. The aerodynamic efficiency reached a maximum L/D ratio of 42.9 at an angle of attack of 2°. Similar aerodynamic trends were observed at Re= 7.5 × 104, although slightly reduced lift and aerodynamic efficiency were recorded due to stronger viscous effects at lower Reynolds numbers. The pitching moment coefficient varied approximately linearly with angle of attack, with a slope of −7.8 × 10−3 per degree and a zero-lift moment value of −7.47 × 10−3, indicating stable longitudinal aerodynamic behavior. Flow visualization results revealed a gradual transition from attached laminar flow to separated turbulent flow, suggesting smoother stall development and improved flow stability for the bioinspired configuration. These findings highlight the aerodynamic advantages of swallow-inspired wing geometries and their potential to enhance aerodynamic efficiency in low Reynolds number flight.