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Numerical investigations on the flow control around airfoils, in conjunction with Coandă effect, based on RANS equations are done. The circulation control uses the tangential blowing jet on the upper surface of the airfoil near the trailing edge with the rounded or modified flatback surface. Flow field spectra around such a configurations, involving the delayed of flow separation are obtained and analyzed by CFD methods. Thus can be identified the optimum domain of the geometric and jet flow parameters in which this flow control method should be used. [ABSTRACT FROM AUTHOR]

Direct airfoil optimization with single or multiple objectives is always required in preliminary aircraft design. Low fidelity aerodynamic methods like incompressible potential and incompressible boundary layer are still attractive when used under a genetic algorithm that although is relatively slow, it enables the identification of the global solution while handling generic constraints in a simple way. The work is focused on small angles of attack, for flows without large separations, where the current low fidelity models provide a good level of certainty. Geometric parametrisation of airfoils considers NACA 4, generic polynomial and a combination of Class Shape for thickness and Bernstein polynomials for camber line. Few objective functions are tested and it is shown with numerical results that constraint optimization is fully consistent at high Reynolds, achieving solution uniqueness according to engineering requirements, while for low Reynolds there is a need for special treatment. [ABSTRACT FROM AUTHOR]

This paper aims to achieve a practical study about the quality of the aerodynamic results provided by CFD simulation compared with the high level confidence of the experimental results. Numerical simulation were developed at low Reynolds Number, specific for a high lift airfoil. Some ideas and strategies have been issued for choosing a suitable turbulence model or a suitable low Reynolds airfoil for UAV's or a wind turbine blade. [ABSTRACT FROM AUTHOR]

In this paper we investigated numerically the possibilities to control the dynamic stall phenomenon, with application to vertical axis wind turbines (VAWT). The dynamic stall appears at low tip speed ratio (TSR<4) and it has a great impact on structural integrity of the wind turbine and power performances. For this reason we performed a computational analysis of the dynamic stall phenomenon around NACA 0012 airfoil equipped with passive flow control device, in pitching motion at relative low Reynolds number (~105). Two passive flow control devices have been numerically investigated: turbulence promoter mounted on the leading edge and step on the upper surface of the airfoil. For the present studies, unsteady Reynolds averaged Navier-Stokes (RANS) model is the suitable approach to perform the dynamic stall simulations with an acceptable computational cost and reasonable accuracy. The results are compared to those of an existing experimental case test for unmodified NACA 0012 airfoil. [ABSTRACT FROM AUTHOR]