WaterMedium models for water 
Water: Steam as ideal gas from NASA source 

Water: Simple liquid water medium (incompressible, constant data) 

Water using the IF97 standard, explicit in p and h. Recommended for most applications 

Water using the IF97 standard, explicit in p and T. Recommended for onephase applications 

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

Water using the IF97 standard, explicit in p and T 

Water using the IF97 standard, explicit in p and h 

Water: Steam properties as defined by IAPWS/IF97 standard 

Water: Steam properties as defined by IAPWS/IF97 standard, fixed region 

Region 4 water according to IF97 standard 

Region 5 water according to IF97 standard 

Region 1 (liquid) water according to IF97 standard 

Region 2 (steam) water according to IF97 standard 

Region 1 (liquid) water according to IF97 standard 

Region 2 (steam) water according to IF97 standard 

Region 3 water according to IF97 standard 

Low level and utility computation for high accuracy water properties according to the IAPWS/IF97 standard 
waterConstants 
Value: Type: FluidConstants[1] 

This information is part of the Modelica Standard Library maintained by the Modelica Association.
This package contains different medium models for water:
The WaterIF97 models calculate 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. It has been part of the ThermoFluid Modelica library and been extended, reorganized and documented to become part of the Modelica Standard library.
An important feature that distinguishes this implementation of the IF97 steam property standard is that this implementation has been explicitly designed to work well in dynamic simulations. Computational performance has been of high importance. This means that there often exist several ways to get the same result from different functions if one of the functions is called often but can be optimized for that purpose.
Three variable pairs can be the independent variables of the model:
The following quantities are always computed in Medium.BaseProperties:
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 following functions:
Function call  Unit  Description 
Medium.dynamicViscosity(medium.state)  Pa.s  dynamic viscosity 
Medium.thermalConductivity(medium.state)  W/(m.K)  thermal conductivity 
Medium.prandtlNumber(medium.state)  1  Prandtl number 
Medium.specificEntropy(medium.state)  J/(kg.K)  specific entropy 
Medium.heatCapacity_cp(medium.state)  J/(kg.K)  specific heat capacity at constant pressure 
Medium.heatCapacity_cv(medium.state)  J/(kg.K)  specific heat capacity at constant density 
Medium.isentropicExponent(medium.state)  1  isentropic exponent 
Medium.isentropicEnthalpy(pressure, medium.state)  J/kg  isentropic enthalpy 
Medium.velocityOfSound(medium.state)  m/s  velocity of sound 
Medium.isobaricExpansionCoefficient(medium.state)  1/K  isobaric expansion coefficient 
Medium.isothermalCompressibility(medium.state)  1/Pa  isothermal compressibility 
Medium.density_derp_h(medium.state)  kg/(m3.Pa)  derivative of density by pressure at constant enthalpy 
Medium.density_derh_p(medium.state)  kg2/(m3.J)  derivative of density by enthalpy at constant pressure 
Medium.density_derp_T(medium.state)  kg/(m3.Pa)  derivative of density by pressure at constant temperature 
Medium.density_derT_p(medium.state)  kg/(m3.K)  derivative of density by temperature at constant pressure 
Medium.density_derX(medium.state)  kg/m3  derivative of density by mass fraction 
Medium.molarMass(medium.state)  kg/mol  molar mass 
More details are given in Modelica.Media.UsersGuide.MediumUsage.OptionalProperties. Many additional optional functions are defined to compute properties of saturated media, either liquid (bubble point) or vapour (dew point). The argument to such functions is a SaturationProperties record, which can be set starting from either the saturation pressure or the saturation temperature. With reference to a model defining a pressure p, a temperature T, and a SaturationProperties record sat, the following functions are provided:
Function call  Unit  Description 
Medium.saturationPressure(T)  Pa  Saturation pressure at temperature T 
Medium.saturationTemperature(p)  K  Saturation temperature at pressure p 
Medium.saturationTemperature_derp(p)  K/Pa  Derivative of saturation temperature with respect to pressure 
Medium.bubbleEnthalpy(sat)  J/kg  Specific enthalpy at bubble point 
Medium.dewEnthalpy(sat)  J/kg  Specific enthalpy at dew point 
Medium.bubbleEntropy(sat)  J/(kg.K)  Specific entropy at bubble point 
Medium.dewEntropy(sat)  J/(kg.K)  Specific entropy at dew point 
Medium.bubbleDensity(sat)  kg/m3  Density at bubble point 
Medium.dewDensity(sat)  kg/m3  Density at dew point 
Medium.dBubbleDensity_dPressure(sat)  kg/(m3.Pa)  Derivative of density at bubble point with respect to pressure 
Medium.dDewDensity_dPressure(sat)  kg/(m3.Pa)  Derivative of density at dew point with respect to pressure 
Medium.dBubbleEnthalpy_dPressure(sat)  J/(kg.Pa)  Derivative of specific enthalpy at bubble point with respect to pressure 
Medium.dDewEnthalpy_dPressure(sat)  J/(kg.Pa)  Derivative of specific enthalpy at dew point with respect to pressure 
Medium.surfaceTension(sat)  N/m  Surface tension between liquid and vapour phase 
Details on usage and some examples are given 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.
The documentation of the IAPWS/IF97 steam properties can be freely distributed with computer implementations and are included here (in directory Modelica/Resources/Documentation/Media/Water/IF97documentation):