A Stable and Efficient Nonlinear Aeroelastic Method Using Moving Frames

Abstract

This article presents a new integrated corotational fluid-structure interaction method based on a staggered algorithm to solve nonlinear aeroelastic problems in the time domain. The structural deformation caused by aerodynamic forces is determined using the nonlinear corotational finite element method which models structures undergoing large deformations. A beam corotational element is used to model an airfoil skin and a plate corotational element to model a delta wing. The aerodynamic forces are determined solving the fluid flow Euler equations with respect to multiple moving frames of reference. The multiple moving frames method is improved and its coupling with the corotational structural finite element theory is developed. The original multiple moving frames method had stability problems associated with large structural deformations. This issue is addressed and resolved here. The integrated corotational approach presents an advantage as it does not require deformation or regeneration of the fluid flow grid which is time consuming and frequently generates errors. Two and three-dimensional test cases are solved to illustrate the applicability and stability of the developed formulation. These results highlight the nonlinear effects influence on the dynamic behavior.