Advanced Magnetorheological Fluid Elastomeric Damper for Helicopter Main Rotor Blades

Based on the DoD Rotary Wing Technology Development Approach (RVW-TDA), the objective of this project is to augment inherent rotor blade lag mode (in-plane bending) damping in soft-in-plane rotors by at least 50%, and to strive for an ultimate increase in lag mode damping of 100%. The ultimate goal is to design a rotor that requires neither mechanical nor elastomeric dampers. However, in the near term, substantial improvements to lag damper technology are needed. Techno-Sciences, Inc. in collaboration with Bell Helicopter Textron, Lord Corporation and the University of Maryland, will develop novel magnetorheological fluid elastomeric (MRFE) lag dampers to meet this need, and to ultimately augment stability of the rotor hub of the Army’s H1 helicopter and its variants (Huey, Huey II, Super Cobra), and with direct applicability to the Bell-430 civil helicopter, which has a similar rotor hub configuration. The implementation of adaptive lag damping using magnetorheological fluid elastomeric (MRFE) dampers may greatly enhance stability of the rotor hub over a wide range of temperature, amplitude of motion of blades in the rotor plane (lag mode), and flight conditions. Application of MRFE damper technology to future H-1 rotor upgrades may provide key benefits including high damping to enhance stability augmentation of the rotor in high speed flight conditions, and low damping in flight conditions where damping is not as critical so as to reduce rotor hub loads. The MRFE technology may provide significant savings in aircraft maintenance and operational costs. To enable retro-fit to existing rotor systems, the electrical power required to operate the actuator will be drawn from the DC power bus supplying the main rotor de-icing system. MRFE technology will also enable additional capability on the Bell-430 aircraft, a civil helicopter with a hub/dampers similar to those of the H-1.