This paper explores methods for controlling the boundary layer in the Horizontal Axis Wind Turbine (HAWT) to improve its performance. This study includes passive and active flow control methods at various speeds using numerical and experimental analysis. Most of the simulations in the literature were conducted using Computational Fluid Dynamics (CFD) software, mainly the Reynolds-Averaged Navier–Stokes (RANS) solver, with very few using other solvers. Among the active flow control methods of injection, suction, Co-Flow Jet (CFJ) method, and passive methods of vortex generator, slat, gurney flaps are considered effective for improving the performance of HAWT. Reducing drag and maximizing lift improves the power output and aerodynamic performance of the wind turbine. There have been limited experimental studies using wind tunnels to improve aerodynamic performance through both mechanisms. This study aims to analyze various parameters such as design, velocity, pressure, Reynolds number, and Mach number to delay the separation of incoming and outgoing flows. The use of the flow control method proves to be a useful and promising approach for future wind turbines, while also identifying a research gap. The benefits include lower operating costs, longer lifespan, and quieter operation.