WaterIF97_baseWater: Steam properties as defined by IAPWS/IF97 standard 
Thermodynamic state 

Base properties of water 

Computes density as a function of pressure and specific enthalpy 

Computes temperature as a function of pressure and specific enthalpy 

Compute temperature from pressure and specific enthalpy 

Computes density as a function of pressure and specific enthalpy 

Computes pressure as a function of density and temperature 

Computes specific enthalpy as a function of density and temperature 

Computes specific enthalpy as a function of pressure and temperature 

Computes specific enthalpy as a function of pressure and temperature 

Computes density as a function of pressure and temperature 

Set the thermodynamic state on the dew line 

Set the thermodynamic state on the bubble line 

Dynamic viscosity of water 

Thermal conductivity of water 

Surface tension in two phase region of water 

Return pressure of ideal gas 

Return temperature of ideal gas 

Return density of ideal gas 

Return specific enthalpy 

Return specific internal energy 

Return specific Gibbs energy 

Return specific Helmholtz energy 

Specific entropy of water 

Specific heat capacity at constant pressure of water 

Specific heat capacity at constant volume of water 

Return isentropic exponent 

Isothermal compressibility of water 

Isobaric expansion coefficient of water 

Return velocity of sound as a function of the thermodynamic state record 

Compute h(s,p) 

Density derivative by specific enthalpy 

Density derivative by pressure 

Boiling curve specific enthalpy of water 

Dew curve specific enthalpy of water 

Boiling curve specific entropy of water 

Dew curve specific entropy of water 

Boiling curve specific density of water 

Dew curve specific density of water 

Saturation temperature of water 

Derivative of saturation temperature w.r.t. pressure 

Saturation pressure of water 

Bubble point density derivative 

Dew point density derivative 

Bubble point specific enthalpy derivative 

Dew point specific enthalpy derivative 

Return thermodynamic state of water as function of d, T, and optional region 

Return thermodynamic state of water as function of p, h, and optional region 

Return thermodynamic state of water as function of p, s, and optional region 

Return thermodynamic state of water as function of p, T, and optional region 

Return thermodynamic state so that it smoothly approximates: if x > 0 then state_a else state_b 
ThermoStates 
Value: Type: IndependentVariables Description: Enumeration type for independent variables 

mediumName 
Value: "WaterIF97" Type: String Description: Name of the medium 
substanceNames 
Value: {"water"} Type: String[:] Description: Names of the mixture substances. Set substanceNames={mediumName} if only one substance. 
extraPropertiesNames 
Value: fill("", 0) Type: String[:] Description: Names of the additional (extra) transported properties. Set extraPropertiesNames=fill("",0) if unused 
singleState 
Value: false Type: Boolean Description: = true, if u and d are not a function of pressure 
reducedX 
Value: true Type: Boolean Description: = true if medium contains the equation sum(X) = 1.0; set reducedX=true if only one substance (see docu for details) 
fixedX 
Value: true Type: Boolean Description: = true if medium contains the equation X = reference_X 
reference_p 
Value: 101325 Type: AbsolutePressure (Pa) Description: Reference pressure of Medium: default 1 atmosphere 
reference_T 
Value: 298.15 Type: Temperature (K) Description: Reference temperature of Medium: default 25 deg Celsius 
reference_X 
Value: fill(1 / nX, nX) Type: MassFraction[nX] (kg/kg) Description: Default mass fractions of medium 
p_default 
Value: 101325 Type: AbsolutePressure (Pa) Description: Default value for pressure of medium (for initialization) 
T_default 
Value: Modelica.SIunits.Conversions.from_degC(20) Type: Temperature (K) Description: Default value for temperature of medium (for initialization) 
h_default 
Value: specificEnthalpy_pTX(p_default, T_default, X_default) Type: SpecificEnthalpy (J/kg) Description: Default value for specific enthalpy of medium (for initialization) 
X_default 
Value: reference_X Type: MassFraction[nX] (kg/kg) Description: Default value for mass fractions of medium (for initialization) 
C_default 
Value: fill(0, nC) Type: ExtraProperty[nC] Description: Default value for trace substances of medium (for initialization) 
nS 
Value: size(substanceNames, 1) Type: Integer Description: Number of substances 
nX 
Value: nS Type: Integer Description: Number of mass fractions 
nXi 
Value: if fixedX then 0 else if reducedX then nS  1 else nS Type: Integer Description: Number of structurally independent mass fractions (see docu for details) 
nC 
Value: size(extraPropertiesNames, 1) Type: Integer Description: Number of extra (outside of standard massbalance) transported properties 
C_nominal 
Value: 1.0e6 * ones(nC) Type: Real[nC] Description: Default for the nominal values for the extra properties 
smoothModel 
Value: false Type: Boolean Description: True if the (derived) model should not generate state events 
onePhase 
Value: false Type: Boolean Description: True if the (derived) model should never be called with twophase inputs 
fluidConstants 
Value: waterConstants Type: FluidConstants[nS] Description: Constant data for the fluid 
Region 
Value: 0 Type: Integer Description: Region of IF97, if known, zero otherwise 
ph_explicit 
Value: Type: Boolean Description: True if explicit in pressure and specific enthalpy 
dT_explicit 
Value: Type: Boolean Description: True if explicit in density and temperature 
pT_explicit 
Value: Type: Boolean Description: True if explicit in pressure and temperature 
This information is part of the Modelica Standard Library maintained by the Modelica Association.
This model calculates medium properties for water in the liquid, gas and two phase regions according to the IAPWS/IF97 standard, i.e., the accepted industrial standard and best compromise between accuracy and computation time. For more details see Modelica.Media.Water.IF97_Utilities. Three variable pairs can be the independent variables of the model:
The following quantities are always computed:
Variable  Unit  Description 
T  K  temperature 
u  J/kg  specific internal energy 
d  kg/m^3  density 
p  Pa  pressure 
h  J/kg  specific enthalpy 
In some cases additional medium properties are needed. A component that needs these optional properties has to call one of the functions listed in Modelica.Media.UsersGuide.MediumUsage.OptionalProperties and in Modelica.Media.UsersGuide.MediumUsage.TwoPhase.
Many further properties can be computed. Using the wellknown Bridgman's Tables, all first partial derivatives of the standard thermodynamic variables can be computed easily.
Modelica.Media.Water Water: Steam properties as defined by IAPWS/IF97 standard, fixed region 

Modelica.Media.Water Water using the IF97 standard, explicit in p and h 

Modelica.Media.Water Water using the IF97 standard, explicit in p and T 

Modelica.Media.Water Water using the IF97 standard, explicit in p and h, and only valid outside the twophase dome 