New study on active flow control for helicopters
Use of active elements on the surface of a helicopter blade enhances rotor performance, reducing drag, fuel consumption and emissions. Merging expertise from different fields such as fluid dynamics, microelectromechanical (MEMS) systems and composite materials, the EU-funded project IMESCON (Innovative methods of separated flow control in aeronautics) brought 8 early-stage and 13 experienced researchers together to share knowledge on separated flow control methods in helicopters. Project members used numerical simulation and experimental validation to study vortex generators based on a MEMS system actuator of a piezoelectric membrane and Gurney flaps. Study outcomes confirmed the potential of vortex generators to reduce flow separation and thus reduce drag and increase lift. Advanced simulations proved the ability of these small devices to increase the thrust with a minimal power consumption penalty in hovering and forward flight. The team also conducted a study on the potential of another flow control device – a Gurney flap – to alleviate stall during forward flight. Results showed that hovering efficiency slightly improved at increased rotor thrust. Ultimately, IMESCON partners developed an active flow control system mock-up, integrating research outcomes regarding the flow, structure, control and actuators into an overall operational system. The helicopter blade was equipped with the active Gurney flap driven by piezoelectric actuators. IMESCON further explored active flow control technologies and delivered a powerful multi-physics simulation code for designers of helicopter blades. The technologies will reduce fuel consumption and emissions associated with helicopter flight, and increase the efficiency of power generation.
Keywords
Active flow control, helicopters, helicopter blade, IMESCON, vortex generators, Gurney flap
