pyopensn.solver.UncollidedSolver

class pyopensn.solver.UncollidedSolver

Generate and write uncollided flux moments for first-collision transport.

Wrapper of opensn::UncollidedSolver.

Advance(self: pyopensn.solver.Solver) → None

Advance the solver by one step.

Changes made to the problem since the last step are checked as in Execute. Initialize must be called first. Solver classes that do not implement stepping leave the state unchanged and log that Advance is unsupported.

For MPI transport solvers, this is a collective operation and must be called on all ranks.

Execute(self: pyopensn.solver.Solver) → None

Execute the solver.

The problem’s current state and the solver’s requirements are checked first, so changes made to the problem after Initialize (for example a mode switch or SetXSMap) are validated before they are used. Initialize must be called before Execute.

For MPI transport solvers, this is a collective operation and must be called on all ranks.

Initialize(self: pyopensn.solver.Solver) → None

Initialize the solver.

Solvers check that the problem is in a supported state (for example, steady-state mode without external sources for the k-eigenvalue solvers) and raise ValueError otherwise. Setup and post-setup validation must both succeed. Calling Initialize again clears the previous initialized state first.

For MPI transport solvers, this is a collective operation and must be called on all ranks.

__init__(self: pyopensn.solver.UncollidedSolver, **kwargs) → None

Construct an uncollided transport solver.

Parameters:

  • problem (pyopensn.solver.UncollidedProblem) – Existing uncollided problem instance.

  • file_name (str) – Output HDF5 file containing uncollided flux moments, mesh and total cross-section metadata, and production/removal/outflow balance terms.

  • progress_interval (int, default=5) – Percentage interval for source-point progress reports. Reports include completed source points, elapsed time, and estimated remaining time. Set to zero to disable progress reporting. Valid values are integers in [0, 100].

Notes

Initialize() requires exactly one MPI rank. The generated HDF5 file may then be reused by a serial or parallel collided calculation on the same mesh. Execute() uses the problem’s point sources as they are when it runs, including sources replaced after Initialize().

Internal threading in the current uncollided implementation is capped by the OPENSN_NUM_THREADS environment variable and defaults to 1 when the variable is unset or invalid.