SBLI control for wings and inlets

Flow control can be applied to shock wave/boundary layer interactions to achieve two different goals; the delay of shock-induced separation and/or the reduction of stagnation pressure losses, which cause wave drag or inlet inefficiencies. This paper introduces the principles and main techniques for both approaches and assesses their relative suitability for practical applications. While boundary layer suction is already in wide use for separation control, the most promising novel device is the micro-vortex generator, which can deliver similar benefits to traditional vortex generators at much reduced device drag. Shock control is not yet used on practical applications for a number of reasons, but recent research has focused on three-dimensional devices which promise to deliver flow control with improved off-design behaviour. Furthermore, there are some indications that a new generation of control devices may be able to combine the benefits of shock and boundary layer control and reduce shock-induced stagnation pressure losses as well as delay shock-induced separation.