In this technical report we study the convergence of Parareal for 2D incompressible flow around a cylinder for different viscosities. Two methods are used as fine integrator: backward Euler and a fractional step method. It is found that Parareal converges better for the implicit Euler, likely because it under-resolves the fine-scale dynamics as a result of numerical diffusion.
['Andreas Kreienbuehl', 'Arne Naegel', 'Daniel Ruprecht', 'Andreas Vogel', 'Gabriel Wittum', 'Rolf Krause']
Parareal convergence for 2D unsteady flow around a cylinder