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
China
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.