Explicitly uncoupled variational multiscale for characteristic finite element methods based on the unsteady Navier–Stokes equations with high Reynolds number

In this study, we consider the combination of a known method for inducing variational multiscale treatments by postprocessing with known characteristic time stepping methods. Both are interesting for practical computational fluid dynamics applications but this combination has not been explored previously. We prove that the error estimates depend on a reduced Reynolds number. Numerical experiments show that our method improves the numerical performance of the straightforward characteristic method.