  We investigate the Lyapunov spectrum of separated flows and their dependence
on the numerical discretization. The chaotic flow around the NACA 0012 airfoil
at low Reynolds number and large angle of attack is considered to that end, and
t-, h- and p-refinement studies are performed to examine each effect
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. In particular, the asymptotic Lyapunov spectrum for
time refinement is achieved for CFL numbers as large as
$\mathcal{O}(10^1-10^2)$, whereas the system continues to become more and more
chaotic even for meshes that are much finer than the best practice for this
type of flows.
