Application of Shape Memory Alloys Inside a Ram Air Door Rotary Actuator

As the aerospace sector aims to decrease its greenhouse gas emissions from historical levels, vehicle lightweighting is seen as key to achieving meaningful reductions in the sector. Shape memory alloy (SMA) materials have been shown to have extremely high work density that, when applied in an actuator, can yield significant weight savings compared to electric motor and hydraulic powered alternatives. Following a collaboration between Kinitics Automation and Boeing, a high torque rotary actuator was developed which can be scaled to accommodate a wide range of aerospace applications.

To advance the readiness level of the technology, a ram air door application on a 777-series airplane was selected for demonstration. Developed as a line replaceable unit (LRU) for drop-in replacement, the rotary actuator needed to meet strict requirements typically demanded by the aerospace sector. The rotary actuator was developed to be electrically powered, fully self-contained, and environmentally sealed. Leveraging the scalable nature of the platform, multiple SMA material systems were tested under various loads within the same LRU. This project highlights the high value capability of SMA-based actuators for the aerospace sector.