The improvement of helicopter performance represents a challenging target because of the several involved disciplinary areas involved: aerodynamics, aeroacoustics, aeroelasticity, stability/manoeuvrability, propulsion. Among the many and different systems constituting a helicopter, a remarkable influence on the overall efficiency may be attributed to the main rotor; thus, more and more efforts are spent to improve its features, both in hover and forward flight. The classical design strategy aimed at enhancing the rotor efficiency is based on the passive optimization of the rotor blade geometry (i.e. airfoil shape, span length, chord and twist distribution, planform, tip shape). However, due to the different regimes the rotor has to work in, it is not possible to identify a unique configuration, optimal for any flight condition. This leads to consider solutions, belonging to "adaptive" typology, able to affect rotor performance at several regimes: conventional and innovative actuators, locally integrated within the blade to change its shape, dampers for vibration control, local suctions to modify the aerodynamic field, are just some examples of the strategies that are under investigation. According to this trend, within the FRIENDCOPTER European Integrated Project'11, the goal of enhancing the Figure of merit of the BO-105 rotor has been accomplished by affecting the blade twist and the airfoil camber through SMA based actuators. Firstly, numerical investigations have been performed to identify the blade geometry (airfoils and blade tip shape) able to guarantee an optimal Figure of merit in the hover condition; secondly, the design of a SMA based on an actuator able to produce the required twist has been carried out by adopting a dedicated FE approach (MSC/Marc software with the SMA Brinson model implemented); then, a laboratory specimen of the actuator has been manufactured and tested in order to validate numerical predictions; and, finally, the effective benefits in terms of Figure of merit has been estimated.
|Number of pages||11|
|Publication status||Published - 25 Sep 2009|
|Event||35th European Rotorcraft Forum 2009, ERF 2009 - Hamburg, Germany|
Duration: 22 Sep 2009 → 25 Sep 2009
|Conference||35th European Rotorcraft Forum 2009, ERF 2009|
|Abbreviated title||ERF 2009|
|Period||22/09/09 → 25/09/09|
- helicopter rotors
- aerodynamic field
- airfoil shape
- numerical investigations
Pagano, A., Ameduri, S., Cokonaj, V., Prachař, A., Zachariadis, Z., & Drikakis, D. (2009). Helicopter blade twist control through SMA technology: optimal shape prediction, twist actuator realisation and main rotor enhanced performance computation. 587-597. Paper presented at 35th European Rotorcraft Forum 2009, ERF 2009, Hamburg, Germany.