1,642 research outputs found
Dirichlet-Neumann and Neumann-Neumann Waveform Relaxation for the Wave Equation
We present a Waveform Relaxation (WR) version of the Dirichlet-Neumann and
Neumann-Neumann algorithms for the wave equation in space time. Each method is
based on a non-overlapping spatial domain decomposition, and the iteration
involves subdomain solves in space time with corresponding interface condition,
followed by a correction step. Using a Laplace transform argument, for a
particular relaxation parameter, we prove convergence of both algorithms in a
finite number of steps for finite time intervals. The number of steps depends
on the size of the subdomains and the time window length on which the
algorithms are employed. We illustrate the performance of the algorithms with
numerical results, and also show a comparison with classical and optimized
Schwarz WR methods.Comment: 8 pages, 6 figures, presented in 22nd International conference on
Domain Decomposition Methods, to appear in Domain Decomposition in Science
and Engineering XXII, LNCSE, Springer-Verlag 201
Optimized Schwarz waveform relaxation for Primitive Equations of the ocean
In this article we are interested in the derivation of efficient domain
decomposition methods for the viscous primitive equations of the ocean. We
consider the rotating 3d incompressible hydrostatic Navier-Stokes equations
with free surface. Performing an asymptotic analysis of the system with respect
to the Rossby number, we compute an approximated Dirichlet to Neumann operator
and build an optimized Schwarz waveform relaxation algorithm. We establish the
well-posedness of this algorithm and present some numerical results to
illustrate the method
Pipeline Implementations of Neumann-Neumann and Dirichlet-Neumann Waveform Relaxation Methods
This paper is concerned with the reformulation of Neumann-Neumann Waveform
Relaxation (NNWR) methods and Dirichlet-Neumann Waveform Relaxation (DNWR)
methods, a family of parallel space-time approaches to solving time-dependent
PDEs. By changing the order of the operations, pipeline-parallel computation of
the waveform iterates are possible without changing the final solution. The
parallel efficiency and the increased communication cost of the pipeline
implementation is presented, along with weak scaling studies to show the
effectiveness of the pipeline NNWR and DNWR algorithms.Comment: 20 pages, 8 figure
Nonlinear Nonoverlapping Schwarz Waveform Relaxation for Semilinear Wave Propagation
We introduce a non-overlapping variant of the Schwarz waveform relaxation
algorithm for semilinear wave propagation in one dimension. Using the theory of
absorbing boundary conditions, we derive a new nonlinear algorithm. We show
that the algorithm is well-posed and we prove its convergence by energy
estimates and a Galerkin method. We then introduce an explicit scheme. We prove
the convergence of the discrete algorithm with suitable assumptions on the
nonlinearity. We finally illustrate our analysis with numerical experiments.Comment: 20 page
Optimized Schwarz waveform relaxation and discontinuous Galerkin time stepping for heterogeneous problems
We design and analyze a Schwarz waveform relaxation algorithm for domain
decomposition of advection-diffusion-reaction problems with strong
heterogeneities. The interfaces are curved, and we use optimized Robin or
Ventcell transmission conditions. We analyze the semi-discretization in time
with Discontinuous Galerkin as well. We also show two-dimensional numerical
results using generalized mortar finite elements in space
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