BOUTERRA SamiBELAMADI Riyadh (Directeur de Thèse)DJEMILI Abdelouaheb (Co-Directeur de Thèse)2026-05-042026-05-042026-02-11http://dspace-ensti-annaba.dz:4000/handle/123456789/1093This thesis projects addresses the issue of flow separation over wind turbine airfoils under stall conditions via passive boundary layer control. Various configurations and passive control devices are investigated and compared to baseline to yield an optimum configuration. Based on CFD calculations of 2D and 3D steady and unsteady-incompressible flow Reynolds average Navier-Stokes equations, are modeled using RANS and IDDES using ANSYS Fluent. A thorough 2D parametric investigation was held to explore devices such as leading-edge micro cylinders, micro cylinder/slot combination and various slat profiles. Parameters such as position relative to leading-edge, diameter, diameter to gap ratio, slat’s inclination angle camber, chord length and position were taken into account in this study. Validation was performed in comparison to experimental results available for the S809 profile. 2D and 3D peculiar Mechanisms that govern and influence separation and induce efficient control were identified. A particular interest was directed towards the slat case using a IDDES-FWH study. Further deepening and investigation were necessary to evaluate the 3D effects using a comparison study of slot and slat validated configuration implemented on the S809 Phase II blade. The slotted phase VI blade has also been studied. Aeroacoustic effect of both slat and slot implementation over the whole blade span resulted in high acoustic emission at high frequencies.frPassive flow controlboundary layer separationwind energy,CFD-RANSIDDES-FWHturbulence sheddingangle of attackThesis