This is an abstract base class which different Solver subclasses implement for different architectures or source iteration algorithms. More...

#include "src/Solver.h"

Public Member Functions
	Solver (TrackGenerator *track_generator=NULL)
	Constructor initializes an empty Solver class with array pointers set to NULL. More...

virtual	~Solver ()
	Destructor deletes arrays of boundary angular fluxes, scalar fluxes and sources for each FSR and energy group. More...

void	setGeometry (Geometry *geometry)
	Sets the Geometry for the Solver. More...

Geometry *	getGeometry ()
	Returns a pointer to the Geometry. More...

TrackGenerator *	getTrackGenerator ()
	Returns a pointer to the TrackGenerator. More...

FP_PRECISION	getFSRVolume (long fsr_id)
	Returns the calculated volume for a flat source region. More...

int	getNumPolarAngles ()
	Returns the number of angles used for the polar quadrature. More...

int	getNumIterations ()
	Returns the number of source iterations to converge the source. More...

double	getTotalTime ()
	Returns the total time to converge the source (seconds). More...

double	getKeff ()
	Returns the converged eigenvalue $k_{eff}$ . More...

double	getConvergenceThreshold ()
	Returns the threshold for source/flux convergence. More...

FP_PRECISION	getMaxOpticalLength ()
	Get the maximum allowable optical length for a track segment. More...

bool	isUsingDoublePrecision ()
	Returns whether the solver is using double floating point precision. More...

bool	isUsingExponentialInterpolation ()
	Returns whether the Solver uses linear interpolation to compute exponentials. More...

bool	is3D ()
	Returns whether the Solver is tackling a 3D problem. More...

void	initializeSolver (solverMode solver_mode)
	Initializes most components of Solver. Mostly needed from the Python side.

virtual void	initializeFixedSources ()
	Assigns fixed sources assigned by Cell, Material to FSRs.

void	printFissionRates (std::string fname, int nx, int ny, int nz)
	Prints fission rates to a binary file. More...

virtual void	printInputParamsSummary ()
	A function that prints a summary of the input parameters.

void	setKeffFromNeutronBalance ()
	Sets computation method of k-eff from fission, absorption, and leakage rates rather than from fission rates. keff = fission/(absorption + leakage)

void	setResidualByReference (std::string fname)
	Sets residuals to be computed a error relative to a reference. More...

void	dumpFSRFluxes (std::string fname)
	Prints scalar fluxes to a binary file. More...

void	loadInitialFSRFluxes (std::string fname)
	Load the initial scalar flux distribution from a binary file. More...

void	loadFSRFluxes (std::string fname, bool assign_k_eff=false, double tolerance=0.01)
	Load scalar fluxes from a binary file. More...

double	getFlux (long fsr_id, int group)
	Returns the scalar flux for some FSR and energy group. More...

virtual void	getFluxes (FP_PRECISION *out_fluxes, int num_fluxes)=0

double	getFSRSource (long fsr_id, int group)
	Returns the source for some energy group for a flat source region. More...

void	setTrackGenerator (TrackGenerator *track_generator)
	Sets the Solver's TrackGenerator with characteristic Tracks. More...

void	setConvergenceThreshold (double threshold)
	Sets the threshold for source/flux convergence. More...

virtual void	setFluxes (FP_PRECISION *in_fluxes, int num_fluxes)=0

virtual void	setFixedSourceByFSR (long fsr_id, int group, double source)
	Assign a fixed source for a flat source region and energy group. More...

void	setFixedSourceByCell (Cell *cell, int group, double source)
	Assign a fixed source for a Cell and energy group. More...

void	setFixedSourceByMaterial (Material *material, int group, double source)
	Assign a fixed source for a Material and energy group. More...

void	setMaxOpticalLength (FP_PRECISION max_optical_length)
	Set the maximum allowable optical length for a track segment. More...

void	setExpPrecision (double precision)
	Set the precision, or maximum allowable approximation error, of the the exponential interpolation table. More...

void	useExponentialInterpolation ()
	Informs the Solver to use linear interpolation to compute the exponential in the transport equation.

void	useExponentialIntrinsic ()
	Informs the Solver to use the exponential intrinsic exp(...) function to compute the exponential in the transport equation.

void	setSolverMode (solverMode solver_mode)
	Choose between direct and adjoint mode. More...

void	setRestartStatus (bool is_restart)
	Informs the Solver that this is a 'restart' calculation and therefore k_eff, track angular and region scalar fluxes should not be reset. More...

void	allowNegativeFluxes (bool negative_fluxes_on)
	Informs the Solver that this calculation may involve negative fluxes for computing higher eigenmodes for example. More...

void	correctXS ()
	Directs OpenMOC to correct unphysical cross-sections. More...

void	stabilizeTransport (double stabilization_factor, stabilizationType stabilization_type=DIAGONAL)
	Directs OpenMOC to use the diagonal stabilizing correction to the source iteration transport sweep. More...

void	setInitialSpectrumCalculation (double threshold)
	Instructs OpenMOC to perform an initial spectrum calculation. More...

void	setCheckXSLogLevel (logLevel log_level)
	Determines which log level to set cross-section warnings. More...

void	setChiSpectrumMaterial (Material *material)
	Sets the chi spectrum for use as an inital flux guess. More...

void	resetMaterials (solverMode mode)
	Returns the Material data to its original state. More...

void	fissionTransportSweep ()
	This method performs one transport sweep using the fission source. More...

void	scatterTransportSweep ()
	This method performs one transport sweep using the scatter source. More...

void	computeFlux (int max_iters=1000, bool only_fixed_source=true)
	Computes the scalar flux distribution by performing a series of transport sweeps. More...

void	computeSource (int max_iters=1000, double k_eff=1.0, residualType res_type=TOTAL_SOURCE)
	Computes the total source distribution by performing a series of transport sweep and source updates. More...

void	computeEigenvalue (int max_iters=1000, residualType res_type=FISSION_SOURCE)
	Computes keff by performing a series of transport sweep and source updates. More...

void	printBGQMemory ()

virtual void	computeFSRFissionRates (double *fission_rates, long num_FSRs, bool nu=false)=0
	Computes the volume-weighted, energy integrated fission rate in each FSR and stores them in an array indexed by FSR ID. More...

float *	getBoundaryFlux (long track_id, bool fwd)
	Returns the boundary flux array at the requested indexes. More...

void	setVerboseIterationReport ()
	Sets the solver to print extra information for each iteration.

void	printTimerReport ()
	Prints a report of the timing statistics to the console.

FP_PRECISION *	getFluxesArray ()
	A function that returns the array of scalar fluxes. More...

void	limitXS ()
	Limits cross-sections so that there are no negative cross-sections. More...

void	setLimitingXSMaterials (std::vector< int > material_ids, int reset_iteration)
	Instructs MOC to limit negative cross-sections for early iterations. More...

void	checkLimitXS (int iteration)
	Checks to see if limited XS should be reset. More...

void	setOTFTransport ()
	Activate On-The-Fly transport, to OTF ray-trace and propagate the track angular fluxes at the same time.

Protected Member Functions
virtual void	initializeFluxArrays ()=0
	Initializes Track boundary angular flux and leakage and FSR scalar flux arrays.

virtual void	initializeSourceArrays ()=0
	Allocates memory for FSR source arrays.

virtual void	initializeExpEvaluators ()
	Initializes new ExpEvaluator object to compute exponentials.

void	initializeMaterials (solverMode mode)
	Initializes the Material's production matrices. More...

virtual void	initializeFSRs ()
	Initializes the FSR volumes and Materials array. More...

void	countFissionableFSRs ()
	Counts the number of fissionable flat source regions. More...

void	checkXS ()
	All material cross-sections in the geometry are checked for consistency. More...

virtual void	initializeCmfd ()
	Initializes a Cmfd object for acceleration prior to source iteration. More...

void	calculateInitialSpectrum (double threshold)
	Performs a spectrum calculation to update the scalar fluxes. More...

virtual void	zeroTrackFluxes ()=0
	Zero each Track's boundary fluxes for each energy group and polar angle in the "forward" and "reverse" directions.

virtual void	flattenFSRFluxes (FP_PRECISION value)=0
	Set the scalar flux for each FSR and energy group to some value. More...

virtual void	flattenFSRFluxesChiSpectrum ()=0
	Set the scalar flux for each FSR to a chi spectrum.

virtual void	storeFSRFluxes ()=0
	Stores the current scalar fluxes in the old scalar flux array.

virtual double	normalizeFluxes ()=0
	Normalizes all FSR scalar fluxes and Track boundary angular fluxes to the total fission source (times $\nu$ ).

virtual void	computeStabilizingFlux ()=0
	Computes the stabilizing flux for transport stabilization.

virtual void	stabilizeFlux ()=0
	Adjusts the scalar flux for transport stabilization.

virtual void	computeFSRSources (int iteration)=0
	Computes the total source (fission, scattering, fixed) for each FSR and energy group.

virtual void	computeFSRFissionSources ()=0
	Computes the total fission source for each FSR and energy group.

virtual void	computeFSRScatterSources ()=0
	Computes the total scattering source for each FSR and energy group.

virtual double	computeResidual (residualType res_type)=0
	Computes the residual between successive flux/source iterations. More...

virtual void	computeKeff ()=0
	Compute $k_{eff}$ from total fission and absorption rates in each FSR and energy group.

virtual void	addSourceToScalarFlux ()=0
	Add the source term contribution in the transport equation to the FSR scalar flux.

virtual void	transportSweep ()=0
	This method performs one transport sweep of all azimuthal angles, Tracks, segments, polar angles and energy groups.

void	clearTimerSplits ()
	Deletes the Timer's timing entries for each timed code section code in the source convergence loop. More...

Protected Attributes
int	_num_azim

int	_num_groups

long	_num_FSRs

long	_num_fissionable_FSRs

FP_PRECISION *	_FSR_volumes

Material **	_FSR_materials

Material *	_chi_spectrum_material

TrackGenerator *	_track_generator

Geometry *	_geometry

int	_num_materials

Quadrature *	_quad

int	_num_polar

int	_fluxes_per_track

Track **	_tracks

std::vector< int >	_limit_xs_materials

int	_reset_iteration

bool	_limit_xs

std::map< int, Material * >	_original_materials

std::map< int, Material * >	_limit_materials

int ***	_tracks_per_stack

bool	_SOLVE_3D

solverMode	_solver_mode

bool	_is_restart

bool	_user_fluxes

bool	_fixed_sources_on

bool	_correct_xs

bool	_stabilize_transport

bool	_verbose

bool	_calculate_initial_spectrum

double	_initial_spectrum_thresh

bool	_load_initial_FSR_fluxes

bool	_calculate_residuals_by_reference

bool	_negative_fluxes_allowed

std::string	_initial_FSR_fluxes_file

std::string	_reference_file

logLevel	_xs_log_level

segmentationType	_segment_formation

long	_tot_num_tracks

float *	_boundary_flux

float *	_start_flux

float *	_boundary_leakage

FP_PRECISION *	_scalar_flux

FP_PRECISION *	_old_scalar_flux

FP_PRECISION *	_reference_flux

FP_PRECISION *	_stabilizing_flux

FP_PRECISION *	_fixed_sources

std::vector< FP_PRECISION * >	_groupwise_scratch

double *	_regionwise_scratch

std::map< std::pair< int, int >, FP_PRECISION >	_fix_src_FSR_map

std::map< std::pair< Cell *, int >, FP_PRECISION >	_fix_src_cell_map

std::map< std::pair< Material *, int >, FP_PRECISION >	_fix_src_material_map

FP_PRECISION *	_reduced_sources

double	_k_eff

bool	_keff_from_fission_rates

int	_num_iterations

double	_converge_thresh

double	_stabilization_factor

stabilizationType	_stabilization_type

ExpEvaluator ***	_exp_evaluators

int	_num_exp_evaluators_azim

int	_num_exp_evaluators_polar

Timer *	_timer

Cmfd *	_cmfd

std::string	_source_type

bool	_OTF_transport

Detailed Description

This is an abstract base class which different Solver subclasses implement for different architectures or source iteration algorithms.

Constructor & Destructor Documentation

◆ Solver()

Solver::Solver ( TrackGenerator * track_generator = NULL )

Constructor initializes an empty Solver class with array pointers set to NULL.

Parameters

track_generator an optional pointer to a TrackGenerator object

◆ ~Solver()

Solver::~Solver ( )

virtual

Destructor deletes arrays of boundary angular fluxes, scalar fluxes and sources for each FSR and energy group.

Deallocates memory for all arrays allocated for the Solver, including fluxes, sources, quadrature weights, and exponential linear interpolation table.

Delete exponential evaluators

Member Function Documentation

◆ allowNegativeFluxes()

void Solver::allowNegativeFluxes ( bool negative_fluxes_on )

Informs the Solver that this calculation may involve negative fluxes for computing higher eigenmodes for example.

Parameters

negative_fluxes_on whether to allow negative fluxes

◆ calculateInitialSpectrum()

void Solver::calculateInitialSpectrum ( double threshold )

protected

Performs a spectrum calculation to update the scalar fluxes.

This function is meant to be used before transport sweeps in an eigenvalue calculation in order to gain a better initial guess on the flux shape. It is equivalent to performing a CMFD update with no current tallies (pure diffusion solve) across a coarse mesh with one mesh cell per domain.

Parameters

threshold The convergence threshold of the calculation

◆ checkLimitXS()

void Solver::checkLimitXS ( int iteration )

Checks to see if limited XS should be reset.

Parameters

iteration The MOC iteration number

◆ checkXS()

void Solver::checkXS ( )

protected

All material cross-sections in the geometry are checked for consistency.

Each cross-section is checked to ensure that the total cross-section is greater than or equal to the scattering cross-section for each energy group and that all cross-sections are positive.

◆ clearTimerSplits()

void Solver::clearTimerSplits ( )

protected

Deletes the Timer's timing entries for each timed code section code in the source convergence loop.

To stop and reset all timer splits

◆ computeEigenvalue()

void Solver::computeEigenvalue	(	int	max_iters = `1000`,
		residualType	res_type = `FISSION_SOURCE`
	)

Computes keff by performing a series of transport sweep and source updates.

This is the main method exposed to the user through the Python interface to perform an eigenvalue calculation. The method makes an initial guess for the scalar and boundary fluxes and performs transport sweeps and source updates until convergence.

By default, this method will perform a maximum of 1000 transport sweeps with a 1E-5 threshold on the integrated FSR fission source. These values may be freely modified by the user at runtime.

The res_type parameter may be used to control the convergence criterion - SCALAR_FLUX, TOTAL_SOURCE and FISSION_SOURCE (default) are all supported options in OpenMOC at this time.

solver.computeEigenvalue(max_iters=100, res_type=FISSION_SOURCE)

Parameters

max_iters	the maximum number of source iterations to allow
res_type	the type of residual used for the convergence criterion

◆ computeFlux()

void Solver::computeFlux	(	int	max_iters = `1000`,
		bool	only_fixed_source = `true`
	)

Computes the scalar flux distribution by performing a series of transport sweeps.

This is the main method exposed to the user through the Python interface to compute the scalar flux distribution, e.g., for a fixed source calculation. This routine makes an initial guess for scalar and boundary fluxes and performs transport sweep until convergence.

By default, this method will perform a maximum of 1000 transport sweeps with a 1E-5 threshold on the average FSR scalar flux. These values may be freely modified by the user at runtime.

The only_fixed_source runtime parameter may be used to control the type of source distribution used in the calculation. By default, this paramter is true and only the fixed sources specified by the user will be considered. Alternatively, when the parameter is false, the source will be computed as the scattering and fission sources resulting from a previously computed flux distribution (e.g., an eigenvalue calculation) in addition to any user-defined fixed sources.

This method may be called by the user to compute the scalar flux for a fixed source distribution from Python as follows:

// Assign fixed sources
// ...
// Find the flux distribution resulting from the fixed sources
solver.computeFlux(max_iters=100)

     Alternatively, as described above, this method may be called by
     the user in Python to compute the flux from a superposition of
     fixed and / or eigenvalue sources as follows:

// Solve for sources and scalar flux distribution
solver.computeEigenvalue(max_iters=1000)
// Add fixed source(s)
// ...
// Find fluxes from superposition of eigenvalue and fixed sources
solver.computeFlux(max_iters=100, only_fixed_source=False)

Parameters

max_iters	the maximum number of source iterations to allow
only_fixed_source	use only fixed sources (true by default)

◆ computeFSRFissionRates()

virtual void Solver::computeFSRFissionRates	(	double *	fission_rates,
		long	num_FSRs,
		bool	nu = `false`
	)

pure virtual

Computes the volume-weighted, energy integrated fission rate in each FSR and stores them in an array indexed by FSR ID.

This is a helper method for SWIG to allow users to retrieve FSR fission rates as a NumPy array. An example of how this method can be called from Python is as follows:

num_FSRs = geometry.getNumFSRs()

fission_rates = solver.computeFSRFissionRates(num_FSRs)

Parameters

fission_rates	an array to store the fission rates (implicitly passed in as a NumPy array from Python)
num_FSRs	the number of FSRs passed in from Python
nu	whether to return nu-fission rates instead of fission rates

Implemented in CPUSolver.

◆ computeResidual()

virtual double Solver::computeResidual ( residualType res_type )

protectedpure virtual

Computes the residual between successive flux/source iterations.

Parameters

res_type the type of residual (FLUX, FISSIOn_SOURCE, TOTAL_SOURCE)

Returns: the total residual summed over FSRs and energy groups

Implemented in GPUSolver, and CPUSolver.

◆ computeSource()

void Solver::computeSource	(	int	max_iters = `1000`,
		double	k_eff = `1.0`,
		residualType	res_type = `TOTAL_SOURCE`
	)

Computes the total source distribution by performing a series of transport sweep and source updates.

This is the main method exposed to the user through the Python interface to compute the source distribution, e.g., for a fixed and/or external source calculation. This routine makes an initial guess for the scalar and boundary fluxes and performs transport sweeps and source updates until convergence.

By default, this method will perform a maximum of 1000 transport sweeps with a 1E-5 threshold on the integrated FSR total source. These values may be freely modified by the user at runtime.

The k_eff parameter may be used for fixed source calculations with fissionable material (e.g., start-up in a reactor from a fixed external source). In this case, the user must "guess" the critical eigenvalue to be be used to scale the fission source.

The res_type parameter may be used to control the convergence criterion - SCALAR_FLUX, TOTAL_SOURCE (default) and FISSION_SOURCE are all supported options in OpenMOC at this time.

This method may be called by the user from Python as follows:

// Assign fixed sources
// ...
// Find the source distribution resulting from the fixed sources
solver.computeSource(max_iters=100, k_eff=0.981)

Parameters

max_iters	the maximum number of source iterations to allow
k_eff	the sub/super-critical eigenvalue (default 1.0)
res_type	the type of residual used for the convergence criterion

◆ correctXS()

void Solver::correctXS ( )

Directs OpenMOC to correct unphysical cross-sections.

If a material is found with greater total scattering cross-section than total cross-section, the total cross-section is set to the scattering cross-section.

◆ countFissionableFSRs()

void Solver::countFissionableFSRs ( )

protected

Counts the number of fissionable flat source regions.

This routine is used by the Solver::computeEigenvalue(...) routine which uses the number of fissionable FSRs to normalize the residual on the fission source distribution.

◆ dumpFSRFluxes()

void Solver::dumpFSRFluxes ( std::string fname )

Prints scalar fluxes to a binary file.

Parameters

fname the name of the file to dump the fluxes to

◆ fissionTransportSweep()

void Solver::fissionTransportSweep ( )

This method performs one transport sweep using the fission source.

This is a helper routine used for Krylov subspace methods.

◆ flattenFSRFluxes()

virtual void Solver::flattenFSRFluxes ( FP_PRECISION value )

protectedpure virtual

Set the scalar flux for each FSR and energy group to some value.

Parameters

value the value to assign to each FSR scalar flux

Implemented in GPUSolver, CPUSolver, and CPULSSolver.

◆ getBoundaryFlux()

float* Solver::getBoundaryFlux	(	long	track_id,
		bool	fwd
	)

inline

Returns the boundary flux array at the requested indexes.

Parameters

track_id	The Track's Unique ID
fwd	Whether the direction of the angular flux along the track is forward (True) or backward (False)

◆ getConvergenceThreshold()

double Solver::getConvergenceThreshold ( )

Returns the threshold for source/flux convergence.

Returns: the threshold for source/flux convergence

◆ getFlux()

double Solver::getFlux	(	long	fsr_id,
		int	group
	)

Returns the scalar flux for some FSR and energy group.

Parameters

fsr_id	the ID for the FSR of interest
group	the energy group of interest

Returns: the FSR scalar flux

◆ getFluxesArray()

FP_PRECISION * Solver::getFluxesArray ( )

A function that returns the array of scalar fluxes.

Returns: The scalar fluxes

◆ getFSRSource()

double Solver::getFSRSource	(	long	fsr_id,
		int	group
	)

Returns the source for some energy group for a flat source region.

This is a helper routine used by the openmoc.process module.

Parameters

fsr_id	the ID for the FSR of interest
group	the energy group of interest

Returns: the flat source region source

◆ getFSRVolume()

FP_PRECISION Solver::getFSRVolume ( long fsr_id )

Returns the calculated volume for a flat source region.

Parameters

fsr_id the flat source region ID of interest

Returns: the flat source region volume

◆ getGeometry()

Geometry * Solver::getGeometry ( )

Returns a pointer to the Geometry.

Returns: a pointer to the Geometry

◆ getKeff()

double Solver::getKeff ( )

Returns the converged eigenvalue $k_{eff}$ .

Returns: the converged eigenvalue $k_{eff}$

◆ getMaxOpticalLength()

FP_PRECISION Solver::getMaxOpticalLength ( )

Get the maximum allowable optical length for a track segment.

Returns: The max optical length

◆ getNumIterations()

int Solver::getNumIterations ( )

Returns the number of source iterations to converge the source.

Returns: the number of iterations

◆ getNumPolarAngles()

int Solver::getNumPolarAngles ( )

Returns the number of angles used for the polar quadrature.

Returns: the number of polar angles

◆ getTotalTime()

double Solver::getTotalTime ( )

Returns the total time to converge the source (seconds).

Returns: the time to converge the source (seconds)

◆ getTrackGenerator()

TrackGenerator * Solver::getTrackGenerator ( )

Returns a pointer to the TrackGenerator.

Returns: a pointer to the TrackGenerator

◆ initializeCmfd()

void Solver::initializeCmfd ( )

protectedvirtual

Initializes a Cmfd object for acceleration prior to source iteration.

Instantiates a dummy Cmfd object if one was not assigned to the Solver by the user and initializes FSRs, materials, fluxes and the Mesh object. This method is for internal use only and should not be called directly by the user.

Reimplemented in CPULSSolver.

◆ initializeFSRs()

void Solver::initializeFSRs ( )

protectedvirtual

Initializes the FSR volumes and Materials array.

This method assigns each FSR a unique, monotonically increasing ID, sets the Material for each FSR, and assigns a volume based on the cumulative length of all of the segments inside the FSR.

Reimplemented in GPUSolver, CPUSolver, and CPULSSolver.

◆ initializeMaterials()

void Solver::initializeMaterials ( solverMode mode )

protected

Initializes the Material's production matrices.

In an adjoint calculation, this routine will transpose the scattering and fission matrices in each material.

Parameters

mode	the solution type (FORWARD or ADJOINT)

◆ is3D()

bool Solver::is3D ( )

Returns whether the Solver is tackling a 3D problem.

Returns: true if the solver is set up with a 3D track generator

◆ isUsingDoublePrecision()

bool Solver::isUsingDoublePrecision ( )

Returns whether the solver is using double floating point precision.

Returns: true if using double precision float point arithmetic

◆ isUsingExponentialInterpolation()

bool Solver::isUsingExponentialInterpolation ( )

Returns whether the Solver uses linear interpolation to compute exponentials.

Returns: true if using linear interpolation to compute exponentials

◆ limitXS()

void Solver::limitXS ( )

Limits cross-sections so that there are no negative cross-sections.

A copy of the original cross-section is saved

◆ loadFSRFluxes()

void Solver::loadFSRFluxes	(	std::string	fname,
		bool	assign_k_eff = `false`,
		double	tolerance = `0.01`
	)

Load scalar fluxes from a binary file.

The matching source regions between the current calculation and those in the loaded file are determined by comparing centroids

Parameters

fname	The file containing the scalar fluxes
assign_k_eff	Whether to set k-eff to the one loaded in the binary file
tolerance	The width of the region in which to search for the matching centroid

◆ loadInitialFSRFluxes()

void Solver::loadInitialFSRFluxes ( std::string fname )

Load the initial scalar flux distribution from a binary file.

Parameters

fname The file containing the scalar fluxes

◆ printFissionRates()

void Solver::printFissionRates	(	std::string	fname,
		int	nx,
		int	ny,
		int	nz
	)

Prints fission rates to a binary file.

Parameters

fname	the name of the file to dump the fission rates to
nx	number of mesh cells in the x-direction
ny	number of mesh cells in the y-direction
nz	number of mesh cells in the z-direction

◆ resetMaterials()

void Solver::resetMaterials ( solverMode mode )

Returns the Material data to its original state.

In an adjoint calculation, the scattering and fission matrices in each material are transposed during initialization. This routine returns both matrices to their original (FORWARD) state at the end of a calculation.

Parameters

mode	the solution type (FORWARD or ADJOINT)

◆ scatterTransportSweep()

void Solver::scatterTransportSweep ( )

This method performs one transport sweep using the scatter source.

This is a helper routine used for Krylov subspace methods.

◆ setCheckXSLogLevel()

void Solver::setCheckXSLogLevel ( logLevel log_level )

Determines which log level to set cross-section warnings.

The default log level is ERROR

Parameters

log_level The log level for outputing cross-section inconsistencies

◆ setChiSpectrumMaterial()

void Solver::setChiSpectrumMaterial ( Material * material )

Sets the chi spectrum for use as an inital flux guess.

Parameters

material The material used for obtaining the chi spectrum

◆ setConvergenceThreshold()

void Solver::setConvergenceThreshold ( double threshold )

Sets the threshold for source/flux convergence.

The default threshold for convergence is 1E-5.

Parameters

threshold the threshold for source/flux convergence

◆ setExpPrecision()

void Solver::setExpPrecision ( double precision )

Set the precision, or maximum allowable approximation error, of the the exponential interpolation table.

By default, the precision is 1E-5 based on the analysis in Yamamoto's 2003 paper.

Parameters

precision the precision of the exponential interpolation table,

◆ setFixedSourceByCell()

void Solver::setFixedSourceByCell	(	Cell *	cell,
		int	group,
		double	source
	)

Assign a fixed source for a Cell and energy group.

This routine will add the fixed source to all instances of the Cell in the geometry (e.g., all FSRs for this Cell).

Parameters

cell	a pointer to the Cell of interest
group	the energy group
source	the volume-averaged source in this group

◆ setFixedSourceByFSR()

void Solver::setFixedSourceByFSR	(	long	fsr_id,
		int	group,
		double	source
	)

virtual

Assign a fixed source for a flat source region and energy group.

This is a helper routine to perform error checking for the subclasses which store the source in the appropriate array.

Parameters

fsr_id	the flat source region ID
group	the energy group
source	the volume-averaged source in this group

◆ setFixedSourceByMaterial()

void Solver::setFixedSourceByMaterial	(	Material *	material,
		int	group,
		double	source
	)

Assign a fixed source for a Material and energy group.

This routine will add the fixed source to all instances of the Material in the geometry (e.g., all FSRs with this Material).

Parameters

material	a pointer to the Material of interest
group	the energy group
source	the volume-averaged source in this group

◆ setGeometry()

void Solver::setGeometry ( Geometry * geometry )

Sets the Geometry for the Solver.

This is a private setter method for the Solver and is not intended to be called by the user.

Parameters

geometry a pointer to a Geometry object

◆ setInitialSpectrumCalculation()

void Solver::setInitialSpectrumCalculation ( double threshold )

Instructs OpenMOC to perform an initial spectrum calculation.

Parameters

threshold The convergence threshold of the spectrum calculation

◆ setLimitingXSMaterials()

void Solver::setLimitingXSMaterials	(	std::vector< int >	material_ids,
		int	reset_iteration
	)

Instructs MOC to limit negative cross-sections for early iterations.

Parameters

material_ids	The material IDs of the cross-sections to limit
reset_iteration	The iteration to reset cross-sections to their defaults

◆ setMaxOpticalLength()

void Solver::setMaxOpticalLength ( FP_PRECISION max_optical_length )

Set the maximum allowable optical length for a track segment.

Parameters

max_optical_length The max optical length

◆ setResidualByReference()

void Solver::setResidualByReference ( std::string fname )

Sets residuals to be computed a error relative to a reference.

Parameters

fname The file containing the flux solution of the reference

◆ setRestartStatus()

void Solver::setRestartStatus ( bool is_restart )

Informs the Solver that this is a 'restart' calculation and therefore k_eff, track angular and region scalar fluxes should not be reset.

Parameters

is_restart whether solver run is a restart run

◆ setSolverMode()

void Solver::setSolverMode ( solverMode solver_mode )

Choose between direct and adjoint mode.

Parameters

solver_mode openmoc.FORWARD or .ADJOINT

◆ setTrackGenerator()

void Solver::setTrackGenerator ( TrackGenerator * track_generator )

Sets the Solver's TrackGenerator with characteristic Tracks.

The TrackGenerator must already have generated Tracks and have used ray tracing to segmentize them across the Geometry. This should be initated in Python prior to assigning the TrackGenerator to the Solver:

geometry.initializeFlatSourceRegions()
track_generator.generateTracks()
solver.setTrackGenerator(track_generator)

Parameters

track_generator a pointer to a TrackGenerator object

◆ stabilizeTransport()

void Solver::stabilizeTransport	(	double	stabilization_factor,
		stabilizationType	stabilization_type = `DIAGONAL`
	)

Directs OpenMOC to use the diagonal stabilizing correction to the source iteration transport sweep.

The source iteration process which MOC uses can be unstable if negative cross-sections arise from transport correction. This instability causes issues in convergence. The stabilizing correction fixes this by adding a diagonal matrix to both sides of the discretized transport equation which introduces no bias but transforms the iteration matrix into one that is stable.

Three stabilization options exist: DIAGONAL, YAMAMOTO, and GLOBAL.

DIAGONAL: The stabilization is only applied to fluxes where the associated in-scatter cross-section is negative. The added stabilizing flux is equal to the magnitude of the in-scatter cross-section divided by the total cross-section and scaled by the stabilization factor. YAMAMOTO: This is the same as DIAGONAL except that the largest stabilization is applied to all regions, not just those containing negative in-scatter cross-sections. GLOBAL: This method applies a global stabilization factor to all fluxes defined by the user. In addition, the stabilization factor in this option refers to a damping factor, not the magnitude of the stabilizing correction.

Parameters

stabilization_factor	The factor applied to the stabilizing correction
stabilization_type	The type of stabilization to use

Member Data Documentation

◆ _boundary_flux

float* Solver::_boundary_flux

protected

The angular fluxes for each Track for all energy groups, polar angles, and azimuthal angles. This array stores the boundary fluxes for a a Track along both "forward" and "reverse" directions.

◆ _boundary_leakage

float* Solver::_boundary_leakage

protected

The angular leakages for each Track. This array stores the weighted outgoing angular fluxes for use in non-CMFD eigenvalue calculations.

◆ _calculate_initial_spectrum

bool Solver::_calculate_initial_spectrum

protected

Boolean for whether to perform a spectrum calculation for the initial flux guess

◆ _calculate_residuals_by_reference

bool Solver::_calculate_residuals_by_reference

protected

Boolean for whether to calculate residuals from reference flux

◆ _chi_spectrum_material

Material* Solver::_chi_spectrum_material

protected

Material to be used for calculating the initial flux guess from chi

◆ _cmfd

Cmfd* Solver::_cmfd

protected

A pointer to a Coarse Mesh Finite Difference (CMFD) acceleration object

◆ _converge_thresh

double Solver::_converge_thresh

protected

The tolerance for converging the source/flux

◆ _correct_xs

bool Solver::_correct_xs

protected

Boolean for whether to correct unphysical cross-sections

◆ _exp_evaluators

ExpEvaluator*** Solver::_exp_evaluators

protected

A matrix of ExpEvaluators to compute exponentials in the transport equation. The matrix is indexed by azimuthal index and polar index

◆ _fix_src_cell_map

std::map< std::pair<Cell*, int>, FP_PRECISION > Solver::_fix_src_cell_map

protected

A mapping of fixed sources keyed by the pair (Cell*, energy group)

◆ _fix_src_FSR_map

std::map< std::pair<int, int>, FP_PRECISION > Solver::_fix_src_FSR_map

protected

A mapping of fixed sources keyed by the pair (FSR ID, energy group)

◆ _fix_src_material_map

std::map< std::pair<Material*, int>, FP_PRECISION > Solver::_fix_src_material_map

protected

A mapping of fixed sources keyed by the pair (Material*, energy group)

◆ _fixed_sources

FP_PRECISION* Solver::_fixed_sources

protected

Optional user-specified fixed sources in each FSR and energy group

◆ _fixed_sources_on

bool Solver::_fixed_sources_on

protected

Boolean to indicate whether there are any fixed sources

◆ _fluxes_per_track

int Solver::_fluxes_per_track

protected

The number of flux varies stored per track in each direction

◆ _FSR_materials

Material** Solver::_FSR_materials

protected

The FSR Material pointers indexed by FSR UID

◆ _FSR_volumes

FP_PRECISION* Solver::_FSR_volumes

protected

The FSR "volumes" (i.e., areas) indexed by FSR UID

◆ _geometry

Geometry* Solver::_geometry

protected

A pointer to a Geometry with initialized FSR offset maps

◆ _groupwise_scratch

std::vector<FP_PRECISION*> Solver::_groupwise_scratch

protected

Temporary scratch pads for intermediate storage of computing steps

◆ _initial_FSR_fluxes_file

std::string Solver::_initial_FSR_fluxes_file

protected

File to load initial FSR fluxes from

◆ _initial_spectrum_thresh

double Solver::_initial_spectrum_thresh

protected

Convergence threshold for the initial spectrum calculation

◆ _is_restart

bool Solver::_is_restart

protected

Indicator of whether the flux array has been defined by the user

◆ _k_eff

double Solver::_k_eff

protected

The current iteration's approximation to k-effective

◆ _keff_from_fission_rates

bool Solver::_keff_from_fission_rates

protected

How to compute the k-effective when not using CMFD

◆ _limit_materials

std::map<int, Material*> Solver::_limit_materials

protected

Map of the materials with limited cross sections

◆ _limit_xs

bool Solver::_limit_xs

protected

Whether to limit cross sections or not

◆ _limit_xs_materials

std::vector<int> Solver::_limit_xs_materials

protected

Ids of materials that will have their cross section limited

◆ _load_initial_FSR_fluxes

bool Solver::_load_initial_FSR_fluxes

protected

Boolean for whether to load initial FSR flux profile from file

◆ _negative_fluxes_allowed

bool Solver::_negative_fluxes_allowed

protected

Boolean for whether the solver allows negative fluxes

◆ _num_azim

int Solver::_num_azim

protected

The number of azimuthal angles

◆ _num_exp_evaluators_azim

int Solver::_num_exp_evaluators_azim

protected

The number of exponential evaluators in the azimuthal direction

◆ _num_exp_evaluators_polar

int Solver::_num_exp_evaluators_polar

protected

The number of exponential evaluators in the polar direction

◆ _num_fissionable_FSRs

long Solver::_num_fissionable_FSRs

protected

The number of fissionable flat source regions

◆ _num_FSRs

long Solver::_num_FSRs

protected

The number of flat source regions

◆ _num_groups

int Solver::_num_groups

protected

The number of energy groups

◆ _num_iterations

int Solver::_num_iterations

protected

The number of source iterations needed to reach convergence

◆ _num_materials

int Solver::_num_materials

protected

The number of Materials

◆ _num_polar

int Solver::_num_polar

protected

The number of polar angles

◆ _old_scalar_flux

FP_PRECISION* Solver::_old_scalar_flux

protected

The old scalar flux for each energy group in each FSR

◆ _original_materials

std::map<int, Material*> Solver::_original_materials

protected

Map of the original materials

◆ _quad

Quadrature* Solver::_quad

protected

A pointer to a polar quadrature

◆ _reduced_sources

FP_PRECISION* Solver::_reduced_sources

protected

Ratios of source to total cross-section for each FSR and energy group

◆ _reference_file

std::string Solver::_reference_file

protected

File to load reference FSR fluxes from

◆ _reference_flux

FP_PRECISION* Solver::_reference_flux

protected

The reference scalar flux for each energy group in each FSR

◆ _reset_iteration

int Solver::_reset_iteration

protected

Iteration at which to revert to original cross sections

◆ _scalar_flux

FP_PRECISION* Solver::_scalar_flux

protected

The scalar flux for each energy group in each FSR

◆ _segment_formation

segmentationType Solver::_segment_formation

protected

Determines the type of track segmentation to use for 3D MOC

◆ _SOLVE_3D

bool Solver::_SOLVE_3D

protected

Boolean for whether to solve in 3D (true) or 2D (false)

◆ _solver_mode

solverMode Solver::_solver_mode

protected

Whether the solver is using the direct or adjoint mode

◆ _source_type

std::string Solver::_source_type

protected

A string indicating the type of source approximation

◆ _stabilization_factor

double Solver::_stabilization_factor

protected

The factor applied to the source iteration stabilization

◆ _stabilization_type

stabilizationType Solver::_stabilization_type

protected

The type of source iteration stabilization

◆ _stabilize_transport

bool Solver::_stabilize_transport

protected

Boolean for whether to apply the stabilizing correction to the source iteration (transport sweep) process

◆ _stabilizing_flux

FP_PRECISION* Solver::_stabilizing_flux

protected

The stabilizing flux for each energy group in each FSR

◆ _timer

Timer* Solver::_timer

protected

A timer to record timing data for a simulation

◆ _tot_num_tracks

long Solver::_tot_num_tracks

protected

The total number of Tracks

◆ _track_generator

TrackGenerator* Solver::_track_generator

protected

A pointer to a TrackGenerator which contains Tracks

◆ _tracks

Track** Solver::_tracks

protected

A pointer to the Tracks array, only for GPUSolver and VectorizedSolver

◆ _tracks_per_stack

int*** Solver::_tracks_per_stack

protected

A pointer to an array with the number of Tracks per azimuthal angle

◆ _user_fluxes

bool Solver::_user_fluxes

protected

Boolean to indicate whether a user loaded his own fluxes

◆ _verbose

bool Solver::_verbose

protected

Boolean for whether to print verbose iteration reports

◆ _xs_log_level

logLevel Solver::_xs_log_level

protected

The log level for outputting cross-section inconsistencies

The documentation for this class was generated from the following files:

/home/guillaume/Research/OpenMOC/src/Solver.h
/home/guillaume/Research/OpenMOC/src/Solver.cpp

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ Solver()

◆ ~Solver()

Member Function Documentation

◆ allowNegativeFluxes()

◆ calculateInitialSpectrum()

◆ checkLimitXS()

◆ checkXS()

◆ clearTimerSplits()

◆ computeEigenvalue()

◆ computeFlux()

◆ computeFSRFissionRates()

◆ computeResidual()

◆ computeSource()

◆ correctXS()

◆ countFissionableFSRs()

◆ dumpFSRFluxes()

◆ fissionTransportSweep()

◆ flattenFSRFluxes()

◆ getBoundaryFlux()

◆ getConvergenceThreshold()

◆ getFlux()

◆ getFluxesArray()

◆ getFSRSource()

◆ getFSRVolume()

◆ getGeometry()

◆ getKeff()

◆ getMaxOpticalLength()

◆ getNumIterations()

◆ getNumPolarAngles()

◆ getTotalTime()

◆ getTrackGenerator()

◆ initializeCmfd()

◆ initializeFSRs()

◆ initializeMaterials()

◆ is3D()

◆ isUsingDoublePrecision()

◆ isUsingExponentialInterpolation()

◆ limitXS()

◆ loadFSRFluxes()

◆ loadInitialFSRFluxes()

◆ printFissionRates()

◆ resetMaterials()

◆ scatterTransportSweep()

◆ setCheckXSLogLevel()

◆ setChiSpectrumMaterial()

◆ setConvergenceThreshold()

◆ setExpPrecision()

◆ setFixedSourceByCell()

◆ setFixedSourceByFSR()

◆ setFixedSourceByMaterial()

◆ setGeometry()

◆ setInitialSpectrumCalculation()

◆ setLimitingXSMaterials()

◆ setMaxOpticalLength()

◆ setResidualByReference()

◆ setRestartStatus()

◆ setSolverMode()

◆ setTrackGenerator()

◆ stabilizeTransport()

Member Data Documentation

◆ _boundary_flux

◆ _boundary_leakage

◆ _calculate_initial_spectrum

◆ _calculate_residuals_by_reference

◆ _chi_spectrum_material

◆ _cmfd

◆ _converge_thresh

◆ _correct_xs

◆ _exp_evaluators

◆ _fix_src_cell_map

◆ _fix_src_FSR_map

◆ _fix_src_material_map

◆ _fixed_sources

◆ _fixed_sources_on

◆ _fluxes_per_track