Exponential time integration using Krylov subspaces

Abstract : The application of exponential integrators based on Krylov techniques to large-scale simulations of complex fluid flows with multiple time-scales demonstrates the efficiency of these schemes in reducing the associated time-step restrictions due to numerical stiffness. Savings of approximately 50% can be achieved for simulations of the three-dimensional compressible Navier-Stokes equations while still maintaining a truncation error typical of explicit time-stepping schemes. Exponential time integration techniques of this type are particularly advantageous for fluid flows with a wide range of temporal scales such as low-Mach number, reactive or acoustically dominated flows. Copyright © 2008 John Wiley & Sons, Ltd.