Comparison of Viscous and Inviscid Unsteady Aerodynamic Loads for Aeroelastic Analyses

摘要

The present work addresses the use of high-fidelity computational fluid dynamics (CFD) formulations in the construction of the aerodynamic operator for aeroelastic stability analyses. In particular, the work is concerned with studying the effects of the inclusion of the viscous terms in the aerodynamic formulation, as compared to previous inviscid results. The flows of interest are assumed to be adequately modeled by the 2-D Euler equations or the 2-D Reynolds-averaged Navier-Stokes (RANS) equations with appropriate turbulence closures. The dynamic system is represented by the NACA 0012 airfoil typical section with two degrees of freedom, plunge and pitch. The purely aerodynamic test cases considered for the airfoil, in the transonic regime, include steady and harmonic prescribed motions. Indicial aerodynamic responses of the airfoil, with the current flow solver formulation, are compared to purely inviscid calculations. Furthermore, a root locus stability analysis of the aeroelastic system is performed in order to predict the flutter onset point.