Numerical Investigations of a Wing Leading Edge Comprising Fluid Actuated Morphing Unit Structures (FAMoUS)

Abstract

A large-displacement morphing leading edge "droop nose" device has the potential to enable very high lift coefficients with low airframe noise as has been shown in previous works. A new integrated actuation principle via fluid-actuated morphing unit structures (FAMoUS), demonstrated in previous works, can be implemented in the leading edge instead of conventional linear/rotary actuators and mechanical linkages to enact shape change and to carry load. The advantages of the FAMoUS concept lies in its simplicity of operation and compactness of the skin, substructure, and actuation integrated package. The FAMoUS concept is based on elastomeric chambers that are reinforced with stiffening elements that can generate force and displacement along a specified axis when pressurized with a fluid. This paper investigates the usage of the FAMoUS concept in the leading edge application through numerical finite element analyses. Positive and negative (i.e. vacuum) pressure is considered in different FAMoUS elements along the wing leading edge profile to enable corresponding curvature changes. A parametric study considering different pressure values and thicknesses will provide details about the sensitivities of these parameters in matching a target profile under aerodynamic loads. Different concepts are considered in which the position of the neutral axis in combination with the appropriate direction of pressure (i.e. positive or vacuum) are investigated. Initial simulations of a wing leading edge with chord length 200 mm have been run using nonlinear hyperelastic material models. The results for the aforementioned different concepts show that the leading edge is able to undergo curvature change and the planned parametric studies will be performed via this established tool framework.