Innovative rotor blades - Technology streams

The scope of this subproject is the development and assessment of active and passive technologies based on a two streams strategy. The first one concerns the continuation of the research activities performed within the framework of the FP6 FRIENDCOPTER Integrated Project on active twist technology and the second one based on variation of rotor speed, optimum planform and active rotor system preserving rotor aerodynamic performance and dynamic attributes to maintain stall envelope and reduce vibration. 

Active Twist

It concerns the development of a full scale, active twist blade segment based on integrated piezoelectric actuators (see diagram on the left) to allow the blade shape to be changed in flight to improve performance and/or reduce rotor generated noise. Analysis will be performed to assess future exploitation challenges, benefits in line with GRC1 objectives and airworthiness / safety evaluation. The expected TRL level at the end is planned to be 4. 

Active Gurney Flap

This dynamic blade control surface implements the same aerodynamic concept as steady Gurney flaps used on non rotating parts of some helicopters and airplanes. It will be thoroughly tested in 2D wind tunnel and new CFD modelling techniques have been developed to study the operation and performance. An active Gurney flap system is under development for a full scale main rotor blade and additional partners have been selected to design, manufacture and supply the actuation systems required for model testing and at full scale on a whirl tower. At the end of the program TRL 5 is expected to be achieved

Passive rotor optimisation

This development is based on the use of state of the art, multi-objective, genetic algorithms to assess all possible combinations of blade chord and twist distribution and additional blade features e.g. anhedral (see diagram on the right). An optimised full-scale blade aiming to maximise performance and minimise noise will be tested on a whirl tower.