Development and Analysis-Driven Optimization of Superelastic Slat-Cove Fillers for Airframe Noise Reduction

Experimental Investigation of Flow Around Three-Element High-Lift Airfoil with Morphing Fillers

“…Eventhough several studies [9][10][11][12][13][14][15][16][17][18] have been performed on the noise reduction capabilities of the slat cove filler, only basic aerodynamic and noise measurements have been presented. A detailed experimental study of the aerodynamic performance characteristics such as surface pressure measurements, shear layer measurements and the interaction confluent wakes of all the three-element of the high-lift airfoil has not yet been reported.…”

“…Several experimental and computational studies [9][10][11][12][13][14][15][16][17][18] were made over the past decade to reduce the broadband noise arising from the slat cove region by filling the recirculation area within the slat cove gap. Even though reduction in broadband noise was observed at all the instances it has been a challenge to maintain the aerodynamic performance of the high-lift device for the cove filled configurations.…”

Computational Modeling of a Mechanized Bench-Top Apparatus for Leading-Edge Slat Noise Treatment Device Prototypes

“…Multipiece SCF assemblies, consisting of two SMA flexures separated by a stiffer mid-link, were considered in those studies because of the possibility for controlling the deformation distribution and, consequently, the stowage timing. Although the optimal SCF configuration for this 2D airframe case proved to be a monolithic (one-piece), superelastic SMA with the shortest hinge possible, other SCF configurations that satisfied the application requirements were found in the course of the parametric study and optimization 13,14 . Four of these suboptimal but operable configurations (Mono-2 through Multi-3) are shown with the optimal design (Mono-1) in Figure 11, where the reference lines and dimensions are consistent with the parametric computational model used for the optimization.…”

“…A concept consisting of one or more superelastic shape memory alloy (SMA) components, shape set to the deployed configuration, was found to satisfy the application requirements and provide implementation feasibility. Further work was done to optimize the superelastic-SMA, SCF design to minimize the actuation authority required to stow the structure while satisfying steady-aerodynamic-load and other requirements 13,14 . Recent work has studied means to further reduce actuation requirements 15 .…”

“…The slat-cove filler, shown in Figure 8, was attached to the slat near the cusp, or lower trailing edge, by a hinge and at the upper trailing edge by a riveted lap joint. As mentioned in Section II, simplified physical and computational models were used for parametric study and optimization of the SCF for this 2D airframe, where optimization entailed minimizing the actuator authority required to stow the SCF while satisfying static load and other constraints [12][13][14] . Multipiece SCF assemblies, consisting of two SMA flexures separated by a stiffer mid-link, were considered in those studies because of the possibility for controlling the deformation distribution and, consequently, the stowage timing.…”