Fluid-Structure Interaction Tool For Morphing Blades

Abstract

The design of aeronautical components commonly involves two highly coupled disciplines: aerodynamics and structural mechanics. The interaction between them becomes even more relevant when morphing aeronautical structures are studied. Considering the importance of morphing technology for the future of the aerospace industry, several tools have already been developed to couple these two disciplines together, but all of them deal with pure twodimensional or three-dimensional aero-structural problems. In some circumstances, the study of aeronautical components requires to couple a 2D computational fluid-dynamics (CFD) analysis with a 3D finite element analysis (FEA). This usually happens in the preliminary design phase of aeronautical engine blades (i.e. compressor blades) where the aerodynamic study of the original 3D geometry is replaced by the analysis of a 2D blade cascade in order to reduce the overall computational cost. However, such an approach requires a specific method to couple the 2D CFD geometry/mesh with the 3D FEA geometry/mesh in order to transfer the aerodynamic loads from the CFD analysis to the structural one. As mentioned before, the existing fluid-structure interaction (FSI) tools cannot be implemented to solve a 2D-3D problem; therefore, a novel 2D- 3D aero-structure coupling approach needs to be developed. This paper describes step-by-step the 2D-3D aero-structure coupling strategy applied to the performance analysis of a morphing blade cascade with the goal of enhancing its aerodynamic performance. The results show a relevant decrease in the total pressure losses of the morphing cascade thanks to the adapting blade leading-edge. In order to highlight the reliability of the FSI framework, the developed approach is applied to four different blade configurations which differ in size and location of the two morphing devices.