4 March 2010
Eurocopter has announced that it is working on a number of initiatives to help silence the rotors of its helicopters in order to protect the environment and extend service life
Eurocopter explained that these initiatives include Blue Edge, a “revolutionary main rotor blade provides a passive reduction in noise levels, using a double-swept shape that is very different from present-day blades. The aim of this program is to reduce the noise generated by so-called blade-vortex interactions (BVI), which occur when a blade impacts a vortex, created at the tip of the blade of any helicopter.”
A five-blade Blue Edge main rotor has been flying since July 2007 on an EC155 testbed, logging 75 flight hours and demonstrating noise reductions of 3 to 4 dB.
Blue Pulse, meanwhile, is a piezo-active rotor control system with the primary objective of reducing noise levels generated by the interference of the rotor blade tip vortices from one rotor blade with the following blades. It is designed to “significantly reduce vibrations within the helicopter airframe, increasing passenger comfort and extending the service life of sensitive components.”
The control system uses three flap modules located at the trailing edge of each rotor blade. The blades’ piezoelectric actuators move the rotor flaps 15 to 40 times per second in order to completely neutralize the “slap noise” typically associated with helicopters during descent. The Blue Pulse technology has been flying since 2005, showing a noise reduction of up to 5 dB. Eurocopter’s evaluations with Blue Pulse are continuing on an EC145, while the development of a miniaturized system for production applications is advanced. <a href=”http://www.eurocopter.com”>Click here for more</a>
