pyopensn.solver.NonLinearKEigenSolver

class pyopensn.solver.NonLinearKEigenSolver

Non-linear k-eigenvalue solver.

Wrapper of opensn::NonLinearKEigenSolver.

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

Advance time values function.

ComputeBalanceTable(self: pyopensn.solver.NonLinearKEigenSolver) → dict

Compute and return the global balance table using the solver’s normalization. This is a collective operation and must be called on all ranks.

Returns:

Dictionary with the following entries:

  • absorption_rate: Global absorption rate, approximately integral sigma_a * phi dV summed over groups and the full domain.

  • production_rate: Global volumetric production/source rate used by the solver, approximately integral Q dV summed over groups and the full domain.

  • inflow_rate: Global incoming boundary contribution integrated over incoming angular flux on boundaries.

  • outflow_rate: Global outgoing boundary contribution accumulated from face outflow tallies.

  • balance: Rate balance, production_rate + inflow_rate - absorption_rate - outflow_rate.

Return type:

dict

Notes

For k-eigenvalue balance reporting, this solver scales the production term by 1 / k_eff before forming both production_rate and balance.

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

Execute the solver.

GetEigenvalue(self: pyopensn.solver.NonLinearKEigenSolver) → float

Return the current k-eigenvalue.

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

Initialize the solver.

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

Construct a non-linear k-eigenvalue solver.

Parameters:

  • lbs_problem (pyopensn.solver.LBSProblem) – Existing LBSProblem instance.

  • nl_abs_tol (float, default=1.0e-8) – Non-linear absolute tolerance.

  • nl_rel_tol (float, default=1.0e-8) – Non-linear relative tolerance.

  • nl_sol_tol (float, default=1.0e-50) – Non-linear solution tolerance.

  • nl_max_its (int, default=50) – Non-linear algorithm maximum iterations.

  • l_abs_tol (float, default=1.0e-8) – Linear absolute tolerance.

  • l_rel_tol (float, default=1.0e-8) – Linear relative tolerance.

  • l_div_tol (float, default=1.0e6) – Linear divergence tolerance.

  • l_max_its (int, default=50) – Linear algorithm maximum iterations.

  • l_gmres_restart_intvl (int, default=30) – GMRES restart interval.

  • l_gmres_breakdown_tol (float, default=1.0e6) – GMRES breakdown tolerance.

  • reset_phi0 (bool, default=True) – If true, reinitializes scalar fluxes to 1.0.

  • num_initial_power_iterations (int, default=0) – Number of initial power iterations before the non-linear solve.