Noise Reduction in a High Lift Wing Using SMAs: Computational Fluid-Structural Analysis

The leading-edge-slat on an aircraft is a significant contributor to the airframe noise during the low speed maneuvers of approach and landing. It has been shown in previous work that the slat noise may be reduced with a slat-cove filler (SCF). The objective of this current work is to determine how the SMA SCF behaves under steady flow using finite element structural models and finite volume (FV) fluid models based on a scaled wind tunnel model of a newly considered multi-element wing with a SCF. Computational fluid dynamics (CFD) analysis of the wing is conducted at multiple angles of attack, different flow speeds and high lift device deployment states. The FV fluid models make use of overset meshes, which overlap a slave mesh (that can undergo movement and deformation) unto a fixed master mesh, allowing for retraction and deployment of the slat and flap in the CFD analysis. The structural and fluid models are linked using a previously developed framework that permits the use of custom user material subroutines (for superelastic response of the SMA material) in the structural model, allowing for the performance of fluid-structure interaction (FSI) analysis. The fluid and structural solvers are weakly coupled such that the fluid solver transfers pressure data and the structural solver transfers displacements, but the physical quantities of each program are solved independently. FSI results are shown for the cases of the slat/SCF in the fully-deployed configuration as well as for the case of the slat/SCF undergoing retraction in flow.