Application of three-dimensional interfaces for data transfer in aeroelastic computations

Abstract

A framework of requirements for fluid-structure interfaces is presented and applied to evaluate the qualities of various transfer methods. The Constant-Volume Tetrahedron approach is compared with an inverse Boundary Element Method, both of which are three-dimensional techniques. Advantages of these three-dimensional interfaces over conventional planar interpolation methods (such as the infinite-plate spline interpolation) are demonstrated and discussed. Comparisons are based on geometric considerations as well as on results from aeroelastic computations. For flutter calculations, the three-dimensional Euler equations are solved by a finite-volume method coupled with a finite-difference method for the modal structural equations. The Constant-Volume Tetrahedron approach is more easily implemented as the inverse Boundary Element Method. However, the application of elastic equilibrium in case of the BEM is more physically meaningful than the arbitrary constraint of a constant elemental volume. A detailed comparison of both approaches in terms of implementation and applicability is provided.