Fluid-Structure Interaction of a Variable Camber Compliant Wing

Abstract

This paper presents results for a loosely-coupled fluid-structure interaction (FSI) of a flexible wing using FUN3D to compute the aerodynamic flow-field and Abaqus to calculate the structural deformation. NASA Langley also provides a general 3D algorithm to interpolate between dissimilar meshes which is used here to map pressures and displacements between the aerodynamic and structural codes. This method is applied to the AFRLdeveloped "Variable Camber Compliant Wing" (VCCW), which is an adaptable wing designed target airfoil shapes between a NACA 2410 and 8410. Results will be compared to experiments conducted in the AFRL Vertical Wind Tunnel.

Numerically Efficient Three-Dimensional Fluid-Structure Interaction Analysis for Composite Camber Morphing Aerostructures

“…For example, De Gaspari et al [29] identified the need to study camber morphing at the 3D wing level, and therefore developed a model based on 3D CFD and 3D FEM. Miller et al [30] also developed a FEM/CFD routine for variable camber wings, which also implemented a 3D interpolate algorithm to handle the dissimilar meshes used for structural versus aerodynamic analysis. After experimental validation, it was determined that the FSI model tends to under-predict lift coefficients and trailing edge displacements, and they suggest that a mesh refinement in both FEM and CFD models may improve results.…”

Minimising induced drag with weight distribution, lift distribution, wingspan, and wing-structure weight

“…However, for other aircraft types, these results may not be practical due to additional constraints. Moreover, the results shown in Equations (23)- (27) and (29)- (33) are for a rectangular wing with the weight distribution given in Equations (5) and (6), which minimises the bending moment required for any given wingspan at the constraining design limit. However, the reader is reminded that this weight distribution is not always practical due to other design constraints.…”

“…Therefore, in order for this constraint to be satisfied, we must assume that wing twist can be varied during flight to maintain a single lift distribution at all loading conditions. This can be done using variable geometric and/or aerodynamic twist (30)(31)(32)(33)(34)(35) . However, the designer is not always constrained to a single lift distribution.…”

“…However, the designer is not always constrained to a single lift distribution. Variable geometric and/or aerodynamic twist can also be used to implement different lift distributions during different flight phases (4,5,7,8,(30)(31)(32)(33)(34)(35) . For example, the lift distribution given by Equation (13) could be implemented during high-loadfactor manoeuvers; other lift distributions could be implemented during takeoff and landing; and the elliptic lift distribution could be implemented during steady level flight.…”

Development of an Aeroelastic Formulation for Deformable Airfoils Using Orthogonal Polynomials

“…The camber effects on the wing aeroelastic behavior lie in two aspects. For models with a fixed wing box, whereas the leading or trailing edge of the wing is flexible and morphing, such as the MACW [2], the wing with VCCTEF [6], and the variable camber compliant wing designed in AFRL [15,16], the aforementioned aerodynamic impact is dominant, whereas the wing structural dynamic characteristic remains almost unchanged. Therefore, the aeroelastic behavior of the wing can be accurately captured as long as the camber effect is properly modeled in the aerodynamics.…”