Experimental validation of a shape-memory alloy slat-cove filler: Structural response and computational model development

Current and expected Federal Aviation Administration regulations are pressuring the aerospace industry to develop new technologies that reduce aeroacoustic emissions, which may affect the health and well-being of community members. With recent technological advancements reducing noise emissions from aircraft engines, airframe noise sources now represent a large component of the total emitted noise during approach and landing. This research investigates a shape-memory alloy slat-cove filler concept, which is a promising noise reduction technology for the leading-edge-slat high-lift system. Aerodynamic and structural experiments are conducted with the purpose of characterizing response under relevant flow conditions. A model-scale wing section prototype was treated with a slat-cove filler and used to compare aerodynamic effects of the shape-memory alloy treatment at multiple settings. It is shown that the addition of the slat-cove filler does not detrimentally impact the aerodynamic response of the wing prototype and actually resulted in a higher lift-to-drag ratio. Aerostructural experiments were conducted incorporating Digital Image Correlation measurements and displacement measurements from a custom-designed system based on a laser displacement sensor. These experiments determined the structural response of the shape-memory alloy slat-cove filler during a typical retraction/deployment cycle under relevant wind tunnel test conditions and compared to results from a finite element analysis model.