Nonlinear solvers for unsteady compressible flows

P. Birken, University of Kassel, Germany

Wednesday, April 22
at 16.15, HG E 1.2

We consider the numerical simulation of compressible flows. Already for the Euler equations, implicit methods are often more economic, but the high aspect ratio grids for the Navier-Stokes equations make this type of time integration mandatory. For unsteady flows this results in long sequences of large nonlinear equation systems, which need to be solved. However, contemporary solvers cannot be considered fast. We will present updating techniques for preconditioned Newton-Krylov methods and nonlinear matrix free preconditioners which aim at improving the convergence speed of the nonlinear solver. As a motivational example, we consider a cooling process during steel manufacturing, which employs high pressured air.