The WaterProps class is used to house several approximation routines for properties of water. More...

#include <WaterProps.h>

Detailed Description

The WaterProps class is used to house several approximation routines for properties of water.

This is a helper class for WaterSSTP and PDSS_Water and does not constitute a complete implementation of a thermo phase by itself (see Thermodynamic Properties and classes WaterSSTP and PDSS_Water).

The class is also a wrapper around the WaterPropsIAPWS class which provides the calculations for the equation of state properties for water.

In particular, this class houses methods for the calculation of the dielectric constant of water and the constant A_debye used in the Debye-Huckel and Pitzer activity coefficient calculations.

Definition at line 37 of file WaterProps.h.

Public Member Functions
	WaterProps ()
	Default constructor. More...

	WaterProps (WaterPropsIAPWS *wptr)
	Constructor. More...

	WaterProps (PDSS_Water *wptr)
	Constructor with pointer to Water PDSS object. More...

	WaterProps (const WaterProps &b)=delete

WaterProps &	operator= (const WaterProps &b)=delete

double	relEpsilon (double T, double P_pascal, int ifunc=0)
	Bradley-Pitzer equation for the dielectric constant of water as a function of temperature and pressure. More...

double	ADebye (double T, double P, int ifunc)
	ADebye calculates the value of A_Debye as a function of temperature and pressure according to relations that take into account the temperature and pressure dependence of the water density and dielectric constant. More...

double	satPressure (double T)
	Returns the saturation pressure given the temperature. More...

double	density_IAPWS (double T, double P)
	Returns the density of water. More...

double	density_IAPWS () const
	Returns the density of water. More...

double	coeffThermalExp_IAPWS (double T, double P)
	returns the coefficient of thermal expansion More...

double	isothermalCompressibility_IAPWS (double T, double P)
	Returns the isothermal compressibility of water. More...

Static Public Member Functions
static double	density_T (double T, double P, int ifunc)
	Simple calculation of water density at atmospheric pressure. More...

Protected Attributes
WaterPropsIAPWS *	m_waterIAPWS = nullptr
	Pointer to the WaterPropsIAPWS object. More...

bool	m_own_sub = false
	true if we own the WaterPropsIAPWS object More...

Constructor & Destructor Documentation

◆ WaterProps() [1/3]

WaterProps ( )

Default constructor.

Definition at line 14 of file WaterProps.cpp.

◆ WaterProps() [2/3]

WaterProps ( WaterPropsIAPWS * wptr )

Constructor.

Parameters

wptr	Pointer to WaterPropsIAPWS object

Definition at line 31 of file WaterProps.cpp.

◆ WaterProps() [3/3]

WaterProps ( PDSS_Water * wptr )

Constructor with pointer to Water PDSS object.

Parameters

wptr	Pointer to water standard state object

Definition at line 20 of file WaterProps.cpp.

Member Function Documentation

◆ density_T()

double density_T	(	double	T,
		double	P,
		int	ifunc
	)

static

Simple calculation of water density at atmospheric pressure.

Valid up to boiling point.

This formulation has no dependence on the pressure and shouldn't be used where accuracy is needed.

Parameters

T	temperature in kelvin
P	Pressure in pascal
ifunc	changes what's returned

Returns

value returned depends on ifunc value:

ifunc = 0 Returns the density in kg/m^3
ifunc = 1 returns the derivative of the density wrt T.
ifunc = 2 returns the 2nd derivative of the density wrt T
ifunc = 3 returns the derivative of the density wrt P.

Verification: Agrees with the CRC values (6-10) for up to 4 sig digits.

units = returns density in kg m-3.

Definition at line 48 of file WaterProps.cpp.

◆ relEpsilon()

double relEpsilon	(	double	T,
		double	P_pascal,
		int	ifunc = `0`
	)

Bradley-Pitzer equation for the dielectric constant of water as a function of temperature and pressure.

Returns the dimensionless relative dielectric constant and its derivatives.

Range of validity: 0 to 350C, 0 to 1 kbar pressure

Parameters

T	temperature (kelvin)
P_pascal	pressure in pascal
ifunc	changes what's returned from the function

Returns

Depends on the value of ifunc:

ifunc = 0 return value
ifunc = 1 return temperature derivative
ifunc = 2 return temperature second derivative
ifunc = 3 return pressure first derivative

Validation: Numerical experiments indicate that this function agrees with the Archer and Wang data in the CRC p. 6-10 to all 4 significant digits shown (0 to 100C).

value at 25C and 1 atm, relEps = 78.38

Definition at line 96 of file WaterProps.cpp.

◆ ADebye()

double ADebye	(	double	T,
		double	P,
		int	ifunc
	)

ADebye calculates the value of A_Debye as a function of temperature and pressure according to relations that take into account the temperature and pressure dependence of the water density and dielectric constant.

The A_Debye expression appears on the top of the ln actCoeff term in the general Debye-Huckel expression It depends on temperature and pressure. And, therefore, most be recalculated whenever T or P changes. The units returned by this expression are sqrt(kg/gmol).

\[ A_{Debye} = \frac{1}{8 \pi} \sqrt{\frac{2 N_{Avog} \rho_w}{1000}} {\left(\frac{e^2}{\epsilon k_{boltz} T}\right)}^{\frac{3}{2}} \]

Nominal value at 25C and 1atm = 1.172576 sqrt(kg/gmol).

Based on:

epsilon/epsilon_0 = 78.54 (water at 25C)
T = 298.15 K
B_Debye = 3.28640E9 sqrt(kg/gmol)/m

Parameters

T	Temperature (kelvin)
P	pressure (pascal)
ifunc	Changes what's returned from the routine

Returns

a double whose meaning depends on ifunc:

ifunc = 0 return value
ifunc = 1 return temperature derivative
ifunc = 2 return temperature second derivative
ifunc = 3 return pressure first derivative

Verification: With the epsRelWater value from the Bradley-Pitzer relation, and the water density from the density_IAPWS() function, The A_Debye computed with this function agrees with the Pitzer table p. 99 to 4 significant digits at 25C. and 20C. (Aphi = ADebye/3)

Definition at line 147 of file WaterProps.cpp.

◆ satPressure()

double satPressure ( double T )

Returns the saturation pressure given the temperature.

Parameters

T	temperature (kelvin)

Returns: the saturation pressure (pascal)

Definition at line 220 of file WaterProps.cpp.

◆ density_IAPWS() [1/2]

double density_IAPWS	(	double	T,
		double	P
	)

Returns the density of water.

This function sets the internal temperature and pressure of the underlying object at the same time.

Parameters

T	Temperature (kelvin)
P	pressure (pascal)

Definition at line 225 of file WaterProps.cpp.

◆ density_IAPWS() [2/2]

double density_IAPWS ( ) const

Returns the density of water.

This function uses the internal state of the underlying water object

Definition at line 230 of file WaterProps.cpp.

◆ coeffThermalExp_IAPWS()

double coeffThermalExp_IAPWS	(	double	T,
		double	P
	)

returns the coefficient of thermal expansion

Parameters

T	Temperature (kelvin)
P	pressure (pascal)

Definition at line 235 of file WaterProps.cpp.

◆ isothermalCompressibility_IAPWS()

double isothermalCompressibility_IAPWS	(	double	T,
		double	P
	)

Returns the isothermal compressibility of water.

Parameters

T	temperature in kelvin
P	pressure in pascal

Definition at line 245 of file WaterProps.cpp.

Member Data Documentation

◆ m_waterIAPWS

WaterPropsIAPWS* m_waterIAPWS = nullptr

protected

Pointer to the WaterPropsIAPWS object.

Definition at line 184 of file WaterProps.h.

◆ m_own_sub

bool m_own_sub = false

protected

true if we own the WaterPropsIAPWS object

Definition at line 187 of file WaterProps.h.

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

Detailed Description

Public Member Functions

Static Public Member Functions

Protected Attributes

Constructor & Destructor Documentation

◆ WaterProps() [1/3]

◆ WaterProps() [2/3]

◆ WaterProps() [3/3]

Member Function Documentation

◆ density_T()

◆ relEpsilon()

◆ ADebye()

◆ satPressure()

◆ density_IAPWS() [1/2]

◆ density_IAPWS() [2/2]

◆ coeffThermalExp_IAPWS()

◆ isothermalCompressibility_IAPWS()

Member Data Documentation

◆ m_waterIAPWS

◆ m_own_sub