Research in Engineering and Aviation
Fluid-Structure Interaction Simulation for the Design of Bio-Inspired Micro Air Vehicle Wings
30th AIAA Applied Aerodynamics Conference. DOI: 10.2514/6.2012-2764
Many biological flyers have evolved to employ flexible wing structures to augment aerodynamic performance. Since Micro Air Vehicles (MAVs) operate in the same flight regime, man-made wing designs have incorporated flexible structures in an attempt to achieve similar enhancements. Quantifying the performance effects of these flexible structures, however, requires simulation of the complex fluid-structure interaction between the wing and the surrounding air. One common approach to this problem involves coupled high-fidelity computational fluid dynamics (CFD) and finite element analysis (FEA), using three-dimensional solid elements. Because using these methods is computationally expensive, simulations are often performed only after a baseline design has been chosen. In response to the high computational cost, some simulations use reduced fidelity methods such as modelling the structure as a single torsion / bending beam or simplifying the aerodynamic model to an analytical model. Many of these simplified methods cannot react to or predict three dimensional surface deformation which can substantially affect the flow around the wing. This paper presents a fluid-structure interaction method for evaluating stationary flexible wings that both models the effects of three-dimensional deformation and is efficient enough to be utilized at the conceptual design stage. The method utilizes an advanced potential flow model for the calculation of aerodynamic loads and a three-dimensional simplified frame/shell finite element model for evaluating the structural response. Combining these two methods considerably reduces the computational cost, and allows for the rapid evaluation of wing performance for a range of operating conditions and structural definitions. Topics discussed in this paper include the formulation of the fluid-structure interaction model, an example trade study performed using the method, and comparisons with the results of higher-fidelity models formulated for this paper and from the literature.