Synergistic Smart Morphing AIleron: Capabilites Identification

Abstract

Unmanned Aerial Vehicles (UAVs) can require adaptation to large changes in flight condition but are restricted by their size. Hybrid actuation systems that excel at both long timescale trim conditions and short timescale deviations, e.g. gusts, can be utilized to augment UAVs controllability. Previously, the Synergistic Smart Morphing Aileron (SSMA) system, a camber-morphing airfoil system utilizing two smart-material actuators operating over different timescales, was introduced and characterized without positional controllers. The combined SSMA system utilizes the comparatively high blocking force of shape-memory alloy (SMA) wires to augment static displacement under high aerodynamic loads while maintaining high-bandwidth tip displacement from the faster piezo-driven MFC actuator. Static aeroelastic simulations have shown that the concept can achieve superior control over flow separation through reflex actuation under aerodynamic loading. This current work further identifies performance capabilities of the SSMA concept that are synergistic in nature, and thus extended beyond that of the constituent actuators in isolation. Dynamic URANS simulations show that allowing the comparatively faster MFC-driven actuator to compensate for the slower SMA wires by actuating through reflex camber mimics the forces of a faster monotonic actuator. By implementing position controllers, an experimental demonstrator is used to initially validate both the static and dynamic benefits of synergistic force control through a hybrid morphing system. Although specific to this configuration, this study exposes how a multi-material, multi-timescale morphing concept can be leveraged to improve steady and unsteady flow control.

Parametric optimization for morphing structures design: application to morphing wings adapting to changing flight conditions

“…As angle of attack continues to increase (7 • ≤ α < 9 • ), the high camber at the front of the airfoil decreases, leading to traditional airfoil shapes (design C). At the highest angles of attack, camber is decreased to delay boundary layer separation, leading to unorthodox designs (design D) known as reflexed airfoils (Jacobs and Pinkerson 1936;Pankonien et al 2016). Each of the identified designs is not acceptable Fig.…”

Aero-structural optimization and analysis of a camber-morphing flying wing: Structural and wind tunnel testing

“…By eliminating the gap between spanwise sections of the wing, the additional drag can be further decreased, as described by Ippolito et al (2013). Concepts investigating spanwise varying camber deflections have been presented by Pankonien et al (2016) and Nguyen et al (2015), which relied on flexible materials in the transition region between discrete camber-morphing devices. In these studies, the entire load-carrying capability is provided by the actuated ribs, as the flexible transition material prevents the load-transfer between the actuated sections.…”

Effects of Speed on Coupled Sweep and Camber in Morphing Wings

“…This design implemented the curved actuation performance of Macro Fiber Composites (MFCs), a piezoelectric actuator, to achieve a smooth trailing edge camber deformation with rapid actuation time. Pankonien et al later extended this design to the Synergistic Smart Morphing Aileron (SSMA), which couples an MFC trailing edge actuator with an antagonistic hinge using Shape Memory Alloy (SMA) wires ahead of the MFCs 10 . When both the MFC and SMA are actuated in the same direction, this allows for a greater range of tip deflection, with the small range of deflection being a shortcoming of many morphing wing designs, compounding the effects of the SMA deflection and the MFC deflection.…”