Removing the CFL stability criterion of the explicit time-domain very high degree spectral-element method with eigenvalue perturbation - CNRS - Centre national de la recherche scientifique Accéder directement au contenu
Article Dans Une Revue Geophysics Année : 2021

Removing the CFL stability criterion of the explicit time-domain very high degree spectral-element method with eigenvalue perturbation

Résumé

The explicit time-domain spectral-element method (SEM) for synthesizing seismograms hasgained tremendous credibility within the seismological community at all scales. Althoughthe recent introduction of non-periodic homogenization has addressed the spatial meshing difficulty of the mechanical discontinuities, the Courant-Friedrichs-Lewy (CFL) stability criterionstrictly constrains the maximum time step, which still puts a great burden on the numericalsimulation. In the explicit time-domain SEM, the source of instability of using a time stepbeyond the stability criterion is that some unstable eigenvalues of the updated matrix are largerthan what can be accurately simulated. We succeed in removing the CFL stability condition inthe explicit time-domain SEM by combining the forward time dispersion-transform method,the eigenvalue perturbation, and the inverse time dispersion-transform method. Our theoretical analyses and numerical experiments both in the homogeneous, moderate and strong heterogeneous models, show that this combination can precisely simulate waveforms with timesteps dozens of the CFL limit even towards the Nyquist limit especially for the efficient veryhigh degree SEM, which abundantly saves the iteration times without suffering from the time-dispersion error. It demonstrates a potential application prospect in some situations such as thefull waveform inversion which requires multiple numerical simulations for the same model.
Fichier principal
Vignette du fichier
geo2020-0623.1.pdf (1.73 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-03306824 , version 1 (29-07-2021)

Identifiants

Citer

Chao Lyu, Yann Capdeville, Gang Lu, Liang Zhao. Removing the CFL stability criterion of the explicit time-domain very high degree spectral-element method with eigenvalue perturbation. Geophysics, 2021, 86 (3), ⟨10.1190/geo2020-0623.1⟩. ⟨hal-03306824⟩
213 Consultations
175 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More