openmc.CMFD¶
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class
openmc.CMFD[source]¶ Parameters that control the use of coarse-mesh finite difference acceleration in OpenMC. This corresponds directly to the cmfd.xml input file.
Variables: - begin (int) – Batch number at which CMFD calculations should begin
- dhat_reset (bool) – Indicate whether \(\widehat{D}\) nonlinear CMFD parameters should be reset to zero before solving CMFD eigenproblem.
- display ({'balance', 'dominance', 'entropy', 'source'}) –
Set one additional CMFD output column. Options are:
- “balance” - prints the RMS [%] of the resdiual from the neutron balance
- equation on CMFD tallies.
- “dominance” - prints the estimated dominance ratio from the CMFD iterations.
- “entropy” - prints the entropy of the CMFD predicted fission source.
- “source” - prints the RMS [%] between the OpenMC fission source and CMFD fission source.
- downscatter (bool) – Indicate whether an effective downscatter cross section should be used when using 2-group CMFD.
- feedback (bool) – Indicate or not the CMFD diffusion result is used to adjust the weight of fission source neutrons on the next OpenMC batch. Defaults to False.
- gauss_seidel_tolerance (Iterable of float) – Two parameters specifying the absolute inner tolerance and the relative inner tolerance for Gauss-Seidel iterations when performing CMFD.
- ktol (float) – Tolerance on the eigenvalue when performing CMFD power iteration
- cmfd_mesh (openmc.CMFDMesh) – Structured mesh to be used for acceleration
- norm (float) – Normalization factor applied to the CMFD fission source distribution
- power_monitor (bool) – View convergence of power iteration during CMFD acceleration
- run_adjoint (bool) – Perform adjoint calculation on the last batch
- shift (float) – Optional Wielandt shift parameter for accelerating power iterations. By default, it is very large so there is effectively no impact.
- spectral (float) – Optional spectral radius that can be used to accelerate the convergence of Gauss-Seidel iterations during CMFD power iteration.
- stol (float) – Tolerance on the fission source when performing CMFD power iteration
- tally_reset (list of int) – List of batch numbers at which CMFD tallies should be reset
- write_matrices (bool) – Write sparse matrices that are used during CMFD acceleration (loss, production) to file