One objective of the European Projects AFLoNext and Clean Sky 2 is to apply Active Flow Control (AFC) on the
airframe in critical aerodynamic areas such as the engine/wing junction or the outer wing region for being able to locally
improve the aerodynamics in certain flight conditions. At the engine/wing junction, AFC is applied to alleviate or even
eliminate flow separation at low speeds and high angle of attacks likely to be associated with the integration of underwing-
mounted Ultra High Bypass Ratio (UHBR) engines and the necessary slat-cut-outs. At the outer wing region, AFC
can be used to allow more aggressive future wing designs with improved performance. A relevant part of the work on
AFC concepts for airframe application is the development of suitable actuators. Fluidic Actuated Flow Control (FAFC)
has been introduced as a Flow Control Technology that influences the boundary layer by actively blowing air through
slots or holes out of the aircraft skin. FAFC actuators can be classified by their Net Mass Flux and accordingly divided
into ZNMF (Zero Net Mass Flux) and NZNMF (Non Zero Net-Mass-Flux) actuators. In the frame of both projects, both
types of the FAFC actuator concepts are addressed. In this paper, the objectives of AFC on the airframe is presented and
the actuators that are used within the project are discussed.
Fluidic Actuated Flow Control (FAFC) has been introduced as a technology that influences the boundary layer by actively blowing air through slots or holes in the aircraft skin or wind turbine rotor blade. Modern wing structures are or will be manufactured using composite materials. In these state of the art systems, AFC actuators are integrated in a hybrid approach. The new idea is to directly integrate the active fluidic elements (such as SJAs and PJAs) and their components in the structure of the airfoil. Consequently, the integration of such fluidic devices must fit the manufacturing process and the material properties of the composite structure. The challenge is to integrate temperature-sensitive active elements and to realize fluidic cavities at the same time. The transducer elements will be provided for the manufacturing steps using roll-to-roll processes. The fluidic parts of the actuators will be manufactured using the MuCell® process that provides on the one hand the defined reproduction of the fluidic structures and, on the other hand, a high light weight index. Based on the first design concept, a demonstrator was developed in order to proof the design approach. The output velocity on the exit was measured using a hot-wire anemometer.
Synthetic Jet Actuators (SJA) are micro fluidic devices with low power and high compactness. They are used for different applications that require a directed air flow. These kind of fluidic generators require zero mass input and produces non-zero momentum output. The classic design of such an actuator consists of a membrane located on one wall of a small cavity and an orifice that is typically on the opposite side of the membrane. In the new SJA concept a Helmholtz resonator is equipped with two transducers to increase the performance of the actuator. The piezoelectric membranes generate the volumetric flow symmetrically from both sides of the chamber. A common outlet connects them to the acoustic far field. A network model  was used for designing and optimizing the SJA. Based on this, a doublewall actuator (DWSJA) was developed. The simulation results show that using two transducers does not fully redouble the exit velocity , but it still shows major improvement in comparison to conventional SJA with single transducers.
Within the EC Clean Sky - Smart Fixed Wing Aircraft initiative concepts for actuating morphing wing structures are under development. In order for developing a complete integrated system including the actuation, the structure to be actuated and the closed loop control unit a hybrid deflection and damage monitoring system is required. The aim of the project "FOS3D" is to develop and validate a fiber optic sensing system based on low-coherence interferometry for simultaneous deflection and damage monitoring. The proposed system uses several distributed and multiplexed fiber optic Michelson interferometers to monitor the strain distribution over the actuated part. In addition the same sensor principle will be used to acquire and locate the acoustic emission signals originated from the onset and growth of defects like impact damages, cracks and delamination’s. Within this paper the authors present the concept, analyses and first experimental results of the mentioned system.