Flow control is a field of fluid dynamics that studies variations of a system configuration that lead to beneficial outcome, such as lift increase, drag or noise reduction, mixing enhancement etc. These variations of a system configuration are achieved using passive or active devices. Passive devices, for example, turbulizators, surface roughness etc., require no energy. Active devices are actuators that require energy, for example, valves or plasma actuators. The systems including these actuators may be either open-loop control systems or depend on the sensors feedback (closed-loop control systems).