The Solver class combines GoverningEquationSolver and BatchTracking to advance the governing equations forward in time, and advect the gas composition. More...

#include <solver.hpp>

Public Member Functions
virtual	~Solver ()
	Declared to avoid the inline compiler-generated default destructor.

	Solver (const arma::uword nGridPoints, const Config &config)
	Construct from Config. More...

	Solver (const arma::uword nGridPoints, const std::string &energyEquation="InternalEnergy", const arma::vec &relaxationFactors={1, 1, 2/3.0}, const std::string &toleranceType="relative", const arma::vec &tolerances={0.001, 0.001, 0.001}, const bool bruteForce=false, const arma::uword maxIterations=200)
	Construct from number of grid points and string to select discretizer. More...

virtual Pipeline	solve (const arma::uword dt, const Pipeline &current, const TimeStep &boundaryConditions, const Physics &physics) const
	Solve the governing equations. More...

virtual Pipeline	solve (const arma::uword dt, const Pipeline &current, const BoundaryConditions &boundaryConditions, const Physics &physics) const
	Solve the governing equations. More...

Pipeline	solveWithIterations (const arma::uword dt, const Pipeline &current, const BoundaryConditions &boundaryConditions, const Physics &physics) const
	Solve the governing equations. More...

void	enableBruteForce ()
	Enable brute force solver, which always does m_maxIterations iterations.

void	setMaxIterations (const arma::uword maxIterations)
	Set max iterations.

arma::uword	nIterations () const
	Return the number of iterations performed during previous solution attempt.

const arma::vec &	relaxationFactors () const
	Get (const ref) relaxation factors.

const std::string &	toleranceType () const
	Get (const ref) tolerance type.

const arma::vec &	tolerances () const
	Get (const ref) tolerances.

const GoverningEquationSolverBase &	governingEquationSolver () const
	Get (const ref) GoverningEquationSolver.

Static Public Member Functions
static arma::uword	differencesWithinTolerance (const Pipeline &guess, const Pipeline &previous, const arma::vec &tolerances, const std::string &toleranceType, const arma::vec &relaxationFactors)
	Check if differences between an old and a new state are within tolerances. This will either compare relative or absolute differences. More...

Private Member Functions
std::unique_ptr< GoverningEquationSolverBase >	makeGoverningEquationSolver (const arma::uword nGridPoints, const Config &config)
	Private method for making GoverningEquationSolverBase instance from Config and nGridPoints. More...

std::unique_ptr< GoverningEquationSolverBase >	makeGoverningEquationSolver (const arma::uword nGridPoints, const std::string &discretizer)
	Private method for making GoverningEquationSolverBase from string and nGridPoints. More...

Private Attributes
arma::vec	m_relaxationFactor
	Relaxation factors for each property (flow, pressure and temperature).

std::string	m_toleranceType

arma::vec	m_tolerances
	Convergence tolerances for each property (flow, pressure and temperature).

bool	m_bruteForce

arma::uword	m_maxIterations

arma::uword	m_nIterations = 0

std::unique_ptr< GoverningEquationSolverBase >	m_governingEquationSolver
	GoverningEquationSolver instance used for solving the governing equations.

std::unique_ptr< BatchTracking >	m_compositionSolver
	BatchTracking instance used to advect composition in the pipeline.

Detailed Description

The Solver class combines GoverningEquationSolver and BatchTracking to advance the governing equations forward in time, and advect the gas composition.

It operates on Pipeline instances, and returns a copy of the input, with updated flow, pressure, temperature, and composition (if batch tracking is enabled).

Constructor & Destructor Documentation

◆ Solver() [1/2]

Solver::Solver	(	const arma::uword	nGridPoints,
		const Config &	config
	)

Construct from Config.

Parameters

nGridPoints	Number of grid points
config	Config instance

◆ Solver() [2/2]

Solver::Solver	(	const arma::uword	nGridPoints,
		const std::string &	energyEquation = `"InternalEnergy"`,
		const arma::vec &	relaxationFactors = `{1, 1, 2/3.0}`,
		const std::string &	toleranceType = `"relative"`,
		const arma::vec &	tolerances = `{0.001, 0.001, 0.001}`,
		const bool	bruteForce = `false`,
		const arma::uword	maxIterations = `200`
	)

explicit

Construct from number of grid points and string to select discretizer.

Parameters

nGridPoints	Number of grid points.
energyEquation	Type of energy equation ("InternalEnergy" or "Enthalpy")
relaxationFactors	Relaxation factors, typically around 1.
toleranceType	Tolerance type ("absolute" or "relative")
tolerances	Convergence criteria
bruteForce	Will always do maxIterations iterations and not check for convergence
maxIterations	The maximum number of iterations to perform

Member Function Documentation

◆ differencesWithinTolerance()

static arma::uword Solver::differencesWithinTolerance	(	const Pipeline &	guess,
		const Pipeline &	previous,
		const arma::vec &	tolerances,
		const std::string &	toleranceType,
		const arma::vec &	relaxationFactors
	)

static

Check if differences between an old and a new state are within tolerances. This will either compare relative or absolute differences.

This is used to see if the iteration over solution of the governing equations have converged, by comparing differences between the two last iterations.

In the case of relative differences, we can run into issues if we have zero flow, so this is handled explicitly (temperature and pressure is never expected to reach zero in well-behaved simulations).

Parameters

guess
previous
tolerances
toleranceType
relaxationFactors

Returns

◆ makeGoverningEquationSolver() [1/2]

std::unique_ptr<GoverningEquationSolverBase> Solver::makeGoverningEquationSolver	(	const arma::uword	nGridPoints,
		const Config &	config
	)

private

Private method for making GoverningEquationSolverBase instance from Config and nGridPoints.

Parameters

config	Config instance
nGridPoints	Number of grid points

Returns: unique_ptr to GoverningEquationSolverBase

◆ makeGoverningEquationSolver() [2/2]

std::unique_ptr<GoverningEquationSolverBase> Solver::makeGoverningEquationSolver	(	const arma::uword	nGridPoints,
		const std::string &	discretizer
	)

private

Private method for making GoverningEquationSolverBase from string and nGridPoints.

Parameters

discretizer	Discretizer type ("InternalEnergy" or "Enthalpy")
nGridPoints	Number of grid points

Returns: unique_ptr to GoverningEquationSolverBase

◆ solve() [1/2]

virtual Pipeline Solver::solve	(	const arma::uword	dt,
		const Pipeline &	current,
		const BoundaryConditions &	boundaryConditions,
		const Physics &	physics
	)		const

virtual

Solve the governing equations.

See also: solveWithIterations()

Parameters

dt	Time step [s]
current	Current pipeline state
boundaryConditions	Boundary conditions
physics	Physics instance to update derived properties and heat transfer

Returns: Copy of current with updated properties.

◆ solve() [2/2]

virtual Pipeline Solver::solve	(	const arma::uword	dt,
		const Pipeline &	current,
		const TimeStep &	boundaryConditions,
		const Physics &	physics
	)		const

virtual

Solve the governing equations.

See also: solveWithIterations()

Parameters

dt	Time step [s]
current	Current pipeline state
boundaryConditions	Boundary conditions with time stamp
physics	Physics instance to update derived properties and heat transfer

Returns: Copy of current with updated properties.

◆ solveWithIterations()

Pipeline Solver::solveWithIterations	(	const arma::uword	dt,
		const Pipeline &	current,
		const BoundaryConditions &	boundaryConditions,
		const Physics &	physics
	)		const

Solve the governing equations.

TODO: Some more documentation here

Parameters

dt	Time step [s]
current	Pipeline state
boundaryConditions	Boundary conditions
physics	Physics instance to update derived properties and heat transfer

Returns: Copy of current with updated properties.

Member Data Documentation

◆ m_bruteForce

bool Solver::m_bruteForce

private

If we should use brute-force solving, which means not checking for convergence, but always performing m_maxIterations iterations.

◆ m_maxIterations

arma::uword Solver::m_maxIterations

private

The maximum number of iterations to perform, or (if m_bruteForce is true) the exact number of iterations to perform.

◆ m_nIterations

arma::uword Solver::m_nIterations = 0

mutableprivate

The number of iterations performed during the previous solution attempt. This is mutable, and is updated in Solver::solve().

◆ m_toleranceType

std::string Solver::m_toleranceType

private

What kind of tolerance to use when checking convergence ("relative" or "absolute").

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

D:/Code/transient-pipeline-flow-gh-pages/src/solver/solver.hpp

Public Member Functions

Static Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ Solver() [1/2]

◆ Solver() [2/2]

Member Function Documentation

◆ differencesWithinTolerance()

◆ makeGoverningEquationSolver() [1/2]

◆ makeGoverningEquationSolver() [2/2]

◆ solve() [1/2]

◆ solve() [2/2]

◆ solveWithIterations()

Member Data Documentation

◆ m_bruteForce

◆ m_maxIterations

◆ m_nIterations

◆ m_toleranceType