Parametric study of square-wave leading-edge blowing on a non-slender delta wing
AEROSPACE SCIENCE AND TECHNOLOGY, vol.176, 2026 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 176
- Publication Date: 2026
- Doi Number: 10.1016/j.ast.2026.112170
- Journal Name: AEROSPACE SCIENCE AND TECHNOLOGY
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex, INSPEC, zbMATH
- Middle East Technical University Affiliated: Yes
Abstract
In the present study, a systematic experimental investigation of active flow control on a 45 degrees swept non-slender delta wing is conducted using periodic leading-edge blowing with square-wave excitation. The experiments are performed in a low-speed wind tunnel employing surface pressure measurements, particle image velocimetry (PIV), and aerodynamic force measurements, supported by an in-house-developed blowing control system. Two square-wave excitation modes, regular and burst-modulated, are examined in comparison with steady blowing. Carrier excitation frequencies ranging from 4 to 64 Hz are tested at duty-cycle settings of 25% and 50%. A detailed characterization of the actuator supply conditions yields an effective momentum coefficient range of 0.25% <= C mu,eff,tot <= 0.68%. The flow field is investigated at a Reynolds number of Re = 9 x 104 over an angle-ofattack range of 0o <= alpha <= 30o. The results demonstrate that excitation frequency is the dominant parameter governing aerodynamic performance and flow field improvement in the stall and post-stall regimes. In particular, regular square-wave excitation at higher frequencies significantly delays lift stall and yields improved pitching moment characteristics in the post-stall region. These improvements are associated with the suppression or modification of three-dimensional surface separation, as indicated by enhanced swirl structure, elimination of surface focal points in streamline topology, and recovery of suction levels in the - Cp distributions relative to the baseline configuration. Overall, the findings indicate that square-wave blowing is an effective and robust strategy for manipulating inherent flow structures and enhancing the aerodynamic performance of non-slender delta wing planforms over a broad range of actuation parameters.