Compositional flash routines for miscible multiphase flow classes with multiple fluid components. More...

#include <PorousFlowFluidStateFlash.h>

Inheritance diagram for PorousFlowFluidStateFlash:

Public Member Functions
	PorousFlowFluidStateFlash (const InputParameters &parameters)

Real	rachfordRice (Real vf, std::vector< Real > &Zi, std::vector< Real > &Ki) const
	Rachford-Rice equation for vapor fraction. More...

Real	rachfordRiceDeriv (Real vf, std::vector< Real > &Zi, std::vector< Real > &Ki) const
	Derivative of Rachford-Rice equation wrt vapor fraction. More...

Real	vaporMassFraction (Real Z0, Real K0, Real K1) const
	Solves Rachford-Rice equation to provide vapor mass fraction. More...

DualReal	vaporMassFraction (const DualReal &Z0, const DualReal &K0, const DualReal &K1) const

Real	vaporMassFraction (std::vector< Real > &Zi, std::vector< Real > &Ki) const

void	initialize () final

void	execute () final

void	finalize () final

unsigned int	numPhases () const
	The maximum number of phases in this model. More...

unsigned int	numComponents () const
	The maximum number of components in this model. More...

unsigned int	aqueousPhaseIndex () const
	The index of the aqueous phase. More...

unsigned int	gasPhaseIndex () const
	The index of the gas phase. More...

unsigned int	aqueousComponentIndex () const
	The index of the aqueous fluid component. More...

unsigned int	gasComponentIndex () const
	The index of the gas fluid component. More...

unsigned int	saltComponentIndex () const
	The index of the salt component. More...

virtual std::string	fluidStateName () const =0
	Name of FluidState. More...

void	clearFluidStateProperties (std::vector< FluidStateProperties > &fsp) const
	Clears the contents of the FluidStateProperties data structure. More...

Protected Attributes
const Real	_nr_max_its
	Maximum number of iterations for the Newton-Raphson routine. More...

const Real	_nr_tol
	Tolerance for Newton-Raphson iterations. More...

unsigned int	_num_phases
	Number of phases. More...

unsigned int	_num_components
	Number of components. More...

const unsigned int	_aqueous_phase_number
	Phase number of the aqueous phase. More...

unsigned int	_gas_phase_number
	Phase number of the gas phase. More...

const unsigned int	_aqueous_fluid_component
	Fluid component number of the aqueous component. More...

unsigned int	_gas_fluid_component
	Fluid component number of the gas phase. More...

const unsigned int	_salt_component
	Salt component index. More...

const Real	_R
	Universal gas constant (J/mol/K) More...

const Real	_T_c2k
	Conversion from C to K. More...

const PorousFlowCapillaryPressure &	_pc
	Capillary pressure UserObject. More...

FluidStateProperties	_empty_fsp
	Empty FluidStateProperties object. More...

Detailed Description

Compositional flash routines for miscible multiphase flow classes with multiple fluid components.

Definition at line 23 of file PorousFlowFluidStateFlash.h.

Constructor & Destructor Documentation

◆ PorousFlowFluidStateFlash()

PorousFlowFluidStateFlash::PorousFlowFluidStateFlash ( const InputParameters & parameters )

Definition at line 21 of file PorousFlowFluidStateFlash.C.

   : PorousFlowFluidStateBase(parameters), _nr_max_its(42), _nr_tol(1.0e-12)
 {
 }

Member Function Documentation

◆ aqueousComponentIndex()

unsigned int PorousFlowFluidStateBase::aqueousComponentIndex ( ) const

inlineinherited

The index of the aqueous fluid component.

Returns: aqueous fluid component number

Definition at line 92 of file PorousFlowFluidStateBase.h.

92 { return _aqueous_fluid_component; };

◆ aqueousPhaseIndex()

unsigned int PorousFlowFluidStateBase::aqueousPhaseIndex ( ) const

inlineinherited

The index of the aqueous phase.

Returns: aqueous phase number

Definition at line 80 of file PorousFlowFluidStateBase.h.

80 { return _aqueous_phase_number; };

◆ clearFluidStateProperties()

void PorousFlowFluidStateBase::clearFluidStateProperties ( std::vector< FluidStateProperties > & fsp ) const

inherited

Clears the contents of the FluidStateProperties data structure.

Parameters

[out] fsp FluidStateProperties data structure with all data initialized to 0

Definition at line 39 of file PorousFlowFluidStateBase.C.

 {
   std::fill(fsp.begin(), fsp.end(), _empty_fsp);
 }

Referenced by PorousFlowWaterNCG::thermophysicalProperties(), PorousFlowFluidStateSingleComponent::thermophysicalProperties(), and PorousFlowBrineCO2::thermophysicalProperties().

◆ execute()

void PorousFlowFluidStateBase::execute ( )

inlinefinalinherited

Definition at line 61 of file PorousFlowFluidStateBase.h.

61 {};

◆ finalize()

void PorousFlowFluidStateBase::finalize ( )

inlinefinalinherited

Definition at line 62 of file PorousFlowFluidStateBase.h.

62 {};

◆ fluidStateName()

virtual std::string PorousFlowFluidStateBase::fluidStateName ( ) const

pure virtualinherited

Name of FluidState.

Implemented in PorousFlowBrineCO2, PorousFlowWaterNCG, and PorousFlowWaterVapor.

◆ gasComponentIndex()

unsigned int PorousFlowFluidStateBase::gasComponentIndex ( ) const

inlineinherited

The index of the gas fluid component.

Returns: gas fluid component number

Definition at line 98 of file PorousFlowFluidStateBase.h.

98 { return _gas_fluid_component; };

◆ gasPhaseIndex()

unsigned int PorousFlowFluidStateBase::gasPhaseIndex ( ) const

inlineinherited

The index of the gas phase.

Returns: gas phase number

Definition at line 86 of file PorousFlowFluidStateBase.h.

86 { return _gas_phase_number; };

◆ initialize()

void PorousFlowFluidStateBase::initialize ( )

inlinefinalinherited

Definition at line 60 of file PorousFlowFluidStateBase.h.

60 {};

◆ numComponents()

unsigned int PorousFlowFluidStateBase::numComponents ( ) const

inlineinherited

The maximum number of components in this model.

Returns: number of components

Definition at line 74 of file PorousFlowFluidStateBase.h.

74 { return _num_components; };

◆ numPhases()

unsigned int PorousFlowFluidStateBase::numPhases ( ) const

inlineinherited

The maximum number of phases in this model.

Returns: number of phases

Definition at line 68 of file PorousFlowFluidStateBase.h.

68 { return _num_phases; };

Referenced by PorousFlowFluidState::PorousFlowFluidState(), and PorousFlowFluidStateSingleComponent::PorousFlowFluidStateSingleComponent().

◆ rachfordRice()

Real PorousFlowFluidStateFlash::rachfordRice	(	Real	vf,
		std::vector< Real > &	Zi,
		std::vector< Real > &	Ki
	)		const

Rachford-Rice equation for vapor fraction.

Can be solved analytically for two components in two phases, but must be solved iteratively using a root finding algorithm for more components. This equation has the nice property that it is monotonic in the interval [0,1], so that only a small number of iterations are typically required to find the root.

The Rachford-Rice equation can also be used to check whether the phase state is two phase, single phase gas, or single phase liquid. Evaluate f(v), the Rachford-Rice equation evaluated at the vapor mass fraction.

If f(0) < 0, then the mixture is below the bubble point, and only a single phase liquid can exist

If f(1) > 0, then the mixture is above the dew point, and only a single phase gas exists.

If f(0) >= 0 and f(1) <= 0, the mixture is between the bubble and dew points, and both gas and liquid phases exist.

Parameters

vf	vapor fraction
Zi	mass fractions
Ki	equilibrium constants

Returns: f(x)

Definition at line 27 of file PorousFlowFluidStateFlash.C.

 {
   const std::size_t num_z = Zi.size();
   // Check that the sizes of the mass fractions and equilibrium constant vectors are correct
   if (Ki.size() != num_z + 1)
     mooseError("The number of mass fractions or equilibrium components passed to rachfordRice is "
                "not correct");
  
   Real f = 0.0;
   Real Z_total = 0.0;
  
   for (std::size_t i = 0; i < num_z; ++i)
   {
     f += Zi[i] * (Ki[i] - 1.0) / (1.0 + x * (Ki[i] - 1.0));
     Z_total += Zi[i];
   }
  
   // Add the last component (with total mass fraction = 1 - z_total)
   f += (1.0 - Z_total) * (Ki[num_z] - 1.0) / (1.0 + x * (Ki[num_z] - 1.0));
  
   return f;
 }

Referenced by vaporMassFraction().

◆ rachfordRiceDeriv()

Real PorousFlowFluidStateFlash::rachfordRiceDeriv	(	Real	vf,
		std::vector< Real > &	Zi,
		std::vector< Real > &	Ki
	)		const

Derivative of Rachford-Rice equation wrt vapor fraction.

Has the nice property that it is strictly negative in the interval [0,1]

Parameters

vf	vapor fraction
Zi	mass fractions
Ki	equilibrium constants

Returns: f'(x)

Definition at line 53 of file PorousFlowFluidStateFlash.C.

 {
   const std::size_t num_Z = Zi.size();
   // Check that the sizes of the mass fractions and equilibrium constant vectors are correct
   if (Ki.size() != num_Z + 1)
     mooseError("The number of mass fractions or equilibrium components passed to rachfordRice is "
                "not correct");
  
   Real df = 0.0;
   Real Z_total = 0.0;
  
   for (std::size_t i = 0; i < num_Z; ++i)
   {
     df -= Zi[i] * (Ki[i] - 1.0) * (Ki[i] - 1.0) / (1.0 + x * (Ki[i] - 1.0)) /
           (1.0 + x * (Ki[i] - 1.0));
     Z_total += Zi[i];
   }
  
   // Add the last component (with total mass fraction = 1 - z_total)
   df -= (1.0 - Z_total) * (Ki[num_Z] - 1.0) * (Ki[num_Z] - 1.0) / (1.0 + x * (Ki[num_Z] - 1.0)) /
         (1.0 + x * (Ki[num_Z] - 1.0));
  
   return df;
 }

Referenced by vaporMassFraction().

◆ saltComponentIndex()

unsigned int PorousFlowFluidStateBase::saltComponentIndex ( ) const

inlineinherited

The index of the salt component.

Returns: salt component number

Definition at line 104 of file PorousFlowFluidStateBase.h.

104 { return _salt_component; };

◆ vaporMassFraction() [1/3]

DualReal PorousFlowFluidStateFlash::vaporMassFraction	(	const DualReal &	Z0,
		const DualReal &	K0,
		const DualReal &	K1
	)		const

Definition at line 87 of file PorousFlowFluidStateFlash.C.

 {
   return (Z0 * (K1 - K0) - (K1 - 1.0)) / ((K0 - 1.0) * (K1 - 1.0));
 }

◆ vaporMassFraction() [2/3]

Real PorousFlowFluidStateFlash::vaporMassFraction	(	Real	Z0,
		Real	K0,
		Real	K1
	)		const

Solves Rachford-Rice equation to provide vapor mass fraction.

For two components, the analytical solution is used, while for cases with more than two components, a Newton-Raphson iterative solution is calculated.

Parameters

Zi	total mass fraction(s)
Ki	equilibrium constant(s)

Returns: vapor mass fraction

Definition at line 81 of file PorousFlowFluidStateFlash.C.

 {
   return (Z0 * (K1 - K0) - (K1 - 1.0)) / ((K0 - 1.0) * (K1 - 1.0));
 }

Referenced by PorousFlowWaterNCG::saturation(), PorousFlowBrineCO2::saturation(), and vaporMassFraction().

◆ vaporMassFraction() [3/3]

Real PorousFlowFluidStateFlash::vaporMassFraction	(	std::vector< Real > &	Zi,
		std::vector< Real > &	Ki
	)		const

Definition at line 95 of file PorousFlowFluidStateFlash.C.

 {
   // Check that the sizes of the mass fractions and equilibrium constant vectors are correct
   if (Ki.size() != Zi.size() + 1)
     mooseError("The number of mass fractions or equilibrium components passed to rachfordRice is "
                "not correct");
   Real v;
  
   // If there are only two components, an analytical solution is possible
   if (Ki.size() == 2)
     v = vaporMassFraction(Zi[0], Ki[0], Ki[1]);
   else
   {
     // More than two components - solve the Rachford-Rice equation using
     // Newton-Raphson method
     // Initial guess for vapor mass fraction
     Real v0 = 0.5;
     unsigned int iter = 0;
  
     while (std::abs(rachfordRice(v0, Zi, Ki)) > _nr_tol)
     {
       v0 = v0 - rachfordRice(v0, Zi, Ki) / rachfordRiceDeriv(v0, Zi, Ki);
       iter++;
  
       if (iter > _nr_max_its)
         break;
     }
     v = v0;
   }
   return v;
 }