Various methods of flow control for enhanced aerodynamic performance have been developed and applied to enhance and control the behavior of aerodynamic components. The use of Coand？ effect for the enhancement of circulation and lift has gained renewed interest, in particular with the progress of CFD. The present work addresses the influence, effectiveness, and configuration of Coand？-jet fitted aerodynamic surface for improving lift and , specifically for S809 airfoil, with a view on its incorporation in the wind turbine. A simple two-dimensional CFD modeling using - turbulence model is utilized to reveal the key elements that could exhibit the desired performance for a series of S809 airfoil configurations. Parametric study performed indicates that the use of Coand？-jet S809 airfoil can only be effective in certain range of trailing edge rounding-off radius, Coand？-jet thickness, and momentum jet size. The location of the Coand？-jet was found to be effective when it is placed close to the trailing edge. The results are compared with experimental data for benchmarking. Three-dimensional configurations are synthesized using certain acceptable assumptions. A trade-off study on the S809 Coand？ configured airfoil is needed to judge the optimum configuration of Coand？-jet fitted Wind-Turbine design. 1. Introduction In line with the efforts to enhance the use of green energy technology for energy extraction, conversion, and propulsion, the fundamental principles and mechanisms that play key roles in these technologies have been the focus in many current research efforts as well as the present research work, since these have the eventual potential of national development significance. Since one of the first attempts to generate electricity by using the wind in the United States by Charles Brush in 1888 [1], wind energy has been utilized for electricity generation using large Wind turbines in many wind farms with potential wind energy inland as well as off-shore. It has been estimated that roughly 10 million MW of energy are continuously available in the earth’s wind [2]. The technical potential of onshore wind energy is very large, 20 × 109 to 50 × 109？MWh per year against the current total annual world electricity consumption of about 15 × 109？MWh. The global wind power capacity installed in the year 2004 was 6614？MW, an increase in total installed generating capacity of nearly 20% from the preceding year. Wind energy conversion research and development efforts have their origin on fluid physics, thermodynamics, and material sciences. Learning from various
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