### ASA 124th Meeting New Orleans 1992 October

## 5aPAb4. Noniterative overlapping domain decomposition method for acoustic
wave propagation.

**E. Priolo
**

**
G. Seriani
**

**
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*Osservatorio Geofisico Sperimentale, P.O. Box 2011, 34016 Trieste, Italy
*

*
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A noniterative overlapping domain decomposition technique for a linear
acoustic wave equation is presented, based on the concept of region of
dependence of a point P. The field computed in P after a time interval (Delta)t
depends on the initial values of the points inside this region, whose extension
depends mainly on (Delta)t that in turn depends on the time integration scheme.
In practice, the original domain is decomposed into overlapping subdomains
containing an interface. The overlaps include the region of dependence of the
interface. The numerical solution is then computed separately and concurrently
on each subdomain. Finally, the fields on each overlap are updated with the
values of the field in the underlying domain. The implementation for an
explicit scheme is straightforward. For implicit schemes, great advantage can
be gained by using a local spatial interpolation. In this work, the spectral
element method and the implicit Newmark method are used, respectively, for
spatial and time integration. The overlap region is reduced to a maximum of two
elements. Numerical results are shown for 1-D and 2-D cases.