Autonomous Camber Morphing of a Helicopter Rotor Blade with Temperature Change using Integrated Shape Memory Alloys

The present study proposes and explores a new autonomous morphing concept, whereby an increase in helicopter rotor blade camber of the order of 12-13° is realized over the inboard section of the blade with increase in ambient temperature. The camber change is achieved through a proper integration of Shape Memory Alloys (SMAs) on the lower surface of the blade aft of the leading-edge spar. For a reference rotor (no-SMA) generating 21,000 lbs thrust, operation in hot conditions resulted in a 2,590lb loss in lift. When the SMA camber morphing section extends from the blade root to 50% span, the rotor recovered up to 43% of the lift loss at high temperature. If the camber-morphing section is further extended to 75% span, up to 82% of the lost lift can be recovered.