Shape Memory Alloy enabled Remote Control Actuated High Speed Cryogenic Wind Tunnel Models

Remote Control Actuation (RCA) of wind tunnel models provides a paradigm shift in high speed wind tunnel testing. Traditional wind tunnel testing involves fabricating and testing numerous fixed parts requiring time consuming model changes in order to test configurations of interest. RCA of wind tunnel models seeks to replace these fixed wind tunnel parts with moving, controllable parts. Thus RCA enables increased productivity, improved data quality and reduced cost of wind tunnel testing. An international team from Boeing, Deharde GmbH, European Transonic Windtunnel (ETW) and NASA Langley Research Center (LaRC) developed and tested a 2D airfoil with a controllable spoiler to demonstrate this technology’s maturity. The spoiler system includes an integrated actuator and brake element enabled by Shape Memory Alloy (SMA) technology. The spoiler airfoil was designed to incorporate a suite of sensors, including pressure taps, thermocouples, spoiler position sensors and strain gages for load sensing. The team designed, built, assembled and laboratory tested the 2D spoiler test article prior to operational testing in the Pilot ETW (PETW) and NASA LaRC 0.3-Meter Transonic Cryogenic Tunnel. The team is currently designing a 787 semi-span model with multiple RCA surfaces including an inboard and outboard spoiler and aileron. This paper will review the design, integration and performance of the SMA actuation system and highlight efforts made to achieve spoiler deflection, aerodynamic loading and thermal management requirements. The successful demonstration of SMA enabled RCA wind tunnel models presented here, is the realization of a potential paradigm shift in wind tunnel testing technology.