The subject of the proposed project LEBox will be design of an integrated leading edge (L/E)-Box with pneumatic flow control devices for mid-scale wind tunnel testing on a suitable swept constant chord (2.5D) model. Dynamic vortex generator jets (VGJs) are chosen as the most suitable active device to control turbulent flow separation at the leading edge. The geometry of these devices in particular with respect to a swept integration will be evaluated to find important parameters such as the optimum skew angle, optimum position at the leading edge and optimum size, e.g. relative to the boundary layer. This will be done by means of comprehensive numerical simulations.
The actuator geometry will be designed for the proposed (new) L/E-Box as well as for an already existing actuator system on the shroud (if a specific wind tunnel model will be used). A new L/E-Box for a swept mid-scale wind tunnel model will be designed to the point of production drawings, manufacturing (preferably by an external partner from the SFWA /WP114 consortium) will be supported. The device will be integrated with the sensor and actuator systems and tested in a mid-scale facility. For these steps background knowledge will be taken from previous or current projects as well as from the results of the numerical evaluation and from previous wind tunnel tests. The results will be analysed with respect to effectiveness, efficiency and to the preparation of large-scale wind tunnel tests.
Active aerodynamics for aeroplane wings
Researchers have developed an active flow-control system to enable the development of innovative high-lift systems for aircraft. The new technologies will play an important role in making future air transport more efficient.
The main aim of the EU-funded LEBOX project was to demonstrate the effectiveness of flow separation control at the leading edge of a swept aerofoil. Aerofoil is the shape of the wing or blade. Dynamic vortex generator jets (VGJs) can suppress turbulent leading-edge flow separation at high angles of attack to increase lift to the maximum extent possible. An important step beyond the state-of-the-art was the creation of actuator geometries for twisted boundary layers to positively influence flow control.
Project members used a technologically advanced Reynolds-averaged Navier–Stokes (RANs) solver for modelling and linked this to wind tunnel testing to optimise the design and placement of VGJs on the aerofoil. The numerical solutions pioneered a new concept of 2.5D simulation. This highlighted the sensitivity of key parameters such as skew and pitch angles, spacing and size relative to the boundary layer. The best set up was found to be a so-called swept constant wing chord.
LEBOX developed a complete design concept and manufactured components that were validated in mid-level wind tunnel tests. Its innovative technologies will play a major role in the development of lighter, more efficient and quieter aircraft. The project has prepared the way for large-scale testing and research into fluidic vortex generators to further increase lift and angle of attack in aircraft.