An efficient and stable finite element solver of higher order in space and time for nonstationary incompressible flow

In this paper, we present fully implicit continuous Galerkin-Petrov (cGP) and discontinuous Galerkin (dG) time-stepping schemes for incompressible flow problems which are, in contrast to standard approaches like for instance the Crank-Nicolson scheme, of higher order in time. In particular, we analyze numerically the higher order dG(1) and cGP(2) methods, which are super convergent of third, resp., fourth order in time, whereas for the space discretization, the well-known LBB-stable finite element pair Q2/<mml:msubsup>P1disc</mml:msubsup> of third-order accuracy is used. The discretized systems of nonlinear equations are treated by using the Newton method, and the associated linear subproblems are solved by means of a monolithic (geometrical) multigrid method with a blockwise Vanka-like smoother treating all components simultaneously. We perform nonstationary simulations (in 2D) for two benchmarking configurations to analyze the temporal accuracy and efficiency of the presented time discretization schemes w.r.t.CPU and numerical costs. As a first test problem, we consider a classical flow around cylinder' benchmark. Here, we concentrate on the nonstationary behavior of the flow patterns with periodic oscillations and examine the ability of the different time discretization schemes to capture the dynamics of the flow. As a second test case, we consider the nonstationary flow through a Venturi pipe'. The objective of this simulation is to control the instantaneous and mean flux through this device. Copyright (c) 2013 John Wiley & Sons, Ltd.