CFD-Corrected Aerodynamic Influence Matrices and Aplications on Aeroelastic Phenomena

Abstract

Abstract The main aim of this study is solution of aeroelastic problems such as flutter, gust and control reversal analysis with Computational Fluid Dynamic (CFD) corrected unsteady aerodynamic instead of inviscid linear results calculated by Doublet Lattice Method (DLM). The DLM is the essential tool for calculating unsteady aerodynamic loads in aeroelasticity. Besides the essential advantages of the DLM, it is based on linear potential flow approach and is only valid for subsonic flow with the assumption of thin airfoil geometry. On the other hand, wing tunnel experiments and high fidelity methods such as Reynolds Avaraged Navier Stoke equations (RANS) are traditional ways to improve aerodynamic behavior fidelity. While the experiments and the CFD based solutions give valid results even for transonic region, the cost of them are higher than the conventional DLM method. Hence, the CFD correction methods have been implemented to increase fidelity of the DLM calculations without computational burdens. The challenge here lies in, the mapping/interpolation of external CFD results to DLM boxes and the generation of correction matrices. The authors presents the CFD interpolation and its commercial application on common sense aeroelastic phenomena; flutter, gust and control reversal analysis which are mentioned in aircraft certification documents with CFD corrected aerodynamic. Once the the methods are applied to models in the frame of industrial mandatories. The comparison is made between with and without the CFD correction.