Computational Framework Based on Variational LES Method for the Multi- Disciplinary Analysis of MAVS With Flapping Wings

摘要

In this paper the three level formulation of a variational multi- scale (VMS) large eddy simulation (LES) method for compressible flow computations is extended for applications involving moving/deforming grids. A consistent method to improve the VMS-LES constant dynamically as the flow develops (dynamic VMS-LES) is also extended for dynamic grid applications. Two applications of VMS-LES for the simulation of separated flow over moving NACA- 0012 extruded airfoil is then presented. The first application involves a qualitative simulation exploring the Knoller-Betz effect of the heaving airfoil at high Strouhal number. The second application is that of the pitching airfoil undergoing dynamic stall. The results predicted by the dynamic VMS-LES method are compared to those obtained with other turbulence models and to experimental data and it is found that the dynamic VMS-LES performs better than the other considered static and dynamic LES models.