Graduate School in Nonlinear Science

Sponsored by the Danish Research Academy

MIDIT                               OFD                           CATS
Modelling, Nonlinear Dynamics       Optics and Fluid Dynamics     Chaos and Turbulence Studies
and Irreversible Thermodynamics     Risø National Laboratory      Niels Bohr Institute and 
Technical University of Denmark     Building 128                  Department of Chemistry
Building 321                        P.O. Box 49                   University of Copenhagen 
DK-2800 Lyngby                      DK-4000 Roskilde              DK-2100 Copenhagen Ø
Denmark                             Denmark                       Denmark


by Chuanju XU
Department of Mathematics
Xiamen University
361005 Xiamen

Laboratoire J.A. Dieudonne de Mathematiques,
UNSA, 06108 Nice, France

Thursday June 17, 1999, 14-15 h
at ET, Institute of Energy Engineering
Fluid Mechanics, Building 404, Room 215

Abstract: The effects on the stability of the treatment of the nonlinear terms are investigated on spectral element approximation of the Navier-Stokes equations. Classical semi-implicit treatment of the convection terms in a time discretization of the Navier-Stokes equations has principal restriction on the time step. This restriction, however, could be relaxed if a characteristic method be used to treat the convective term, with a special emphasis on the determination on the characteristic solution. Detailed comparisons on the stability and the accuracy for different methods are examined. Numerical results on the simulation of the driven cavity flow show that the realized speedup using the characteristic method over classic semi-implicit method is considerable.