Lyapunov spectrum of the separated flow around the NACA 0012 airfoil and its dependence on numerical discretization
Author(s)
Fernandez del Campo, Pablo
Wang, Qiqi
Date Issued
September 2017
Journal
Journal of Computational Physics
Publisher
Elsevier BV
Citation
Fernandez, P., and Q. Wang. "Lyapunov spectrum of the separated flow around the NACA 0012 airfoil and its dependence on numerical discretization." Journal of Computational Physics, 350 (December 2017): 453-469.
Version
Author's final manuscript
Abstract
We investigate the impact of numerical discretization on the Lyapunov spectrum of separated flow simulations. The two-dimensional chaotic flow around the NACA 0012 airfoil at a low Reynolds number and large angle of attack is considered to that end. Time, space and accuracy-order refinement studies are performed to examine each of these effects separately. Numerical results show that the time discretization has a small impact on the dynamics of the system, whereas the spatial discretization can dramatically change them. Also, the finite-time Lyapunov exponents associated to unstable modes are shown to be positively skewed, and quasi-homoclinic tangencies are observed in the attractor of the system. The implications of these results on flow physics and sensitivity analysis of chaotic flows are discussed. Keyword: Computational fluid dynamics; Flow instability; Lyapunov stability analysis; Nonlinear dynamics and chaos; Sensitivity analysis; Separated flows; Turbulence
MIT Department
Massachusetts Institute of Technology. Department of Aeronautics and Astronautics
Massachusetts Institute of Technology. Center for Computational Engineering
Terms of Use
Creative Commons Attribution-NonCommercial-NoDerivs License
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1016/j.jcp.2017.08.056
