Study of passive flow control in an airfoil wing by means of CFD techniques

To study different passive flow control mechanisms for delay separation and increase the performance of an airfoil wing by means of CFD techniques. The idea behind flow control is to improve aerodynamic performance of air and ground vehicles and reduce the drag. The following work covers the study of different passive flow control devices in an airfoil wing. Computational Fluid Dynamics analysis either in Direct Numerical Simulation and Large Eddie Simulation have been carried out to simulate different designs. The airfoil studied is a low-speed-Reynolds airfoil, SD8000, which has the particularity of the formation of a laminar separation bubble over the upper camber at low Reynolds number. Numerical results of the airfoil with no passive flow control device on it have been compared and verified with experimental data in wind tunnels. Two-dimensional simulations have been carried out as well as three-dimensional ones. Results from these devices show differences depending on the type of device studied. Dimple type devices are resulted to be the most efficient ones in terms of aerodynamic optimisation and laminar separation bubble size reduction