WOLFRAM SYSTEMMODELER

IF97_Utilities

Low level and utility computation for high accuracy water properties according to the IAPWS/IF97 standard

Package Contents

BaseIF97

Modelica Physical Property Model: the new industrial formulation IAPWS-IF97

iter

waterBaseProp_ph

Intermediate property record for water

waterBaseProp_ps

Intermediate property record for water

rho_props_ps

Density as function of pressure and specific entropy

rho_ps

Density as function of pressure and specific entropy

T_props_ps

Temperature as function of pressure and specific entropy

T_ps

Temperature as function of pressure and specific entropy

h_props_ps

Specific enthalpy as function or pressure and temperature

h_ps

Specific enthalpy as function or pressure and temperature

phase_ps

Phase as a function of pressure and specific entropy

phase_ph

Phase as a function of pressure and specific enthalpy

phase_dT

Phase as a function of pressure and temperature

rho_props_ph

Density as function of pressure and specific enthalpy

rho_ph

Density as function of pressure and specific enthalpy

rho_ph_der

Derivative function of rho_ph

T_props_ph

Temperature as function of pressure and specific enthalpy

T_ph

Temperature as function of pressure and specific enthalpy

T_ph_der

Derivative function of T_ph

s_props_ph

Specific entropy as function of pressure and specific enthalpy

s_ph

Specific entropy as function of pressure and specific enthalpy

s_ph_der

Specific entropy as function of pressure and specific enthalpy

cv_props_ph

Specific heat capacity at constant volume as function of pressure and specific enthalpy

cv_ph

Specific heat capacity at constant volume as function of pressure and specific enthalpy

regionAssertReal

Assert function for inlining

cp_props_ph

Specific heat capacity at constant pressure as function of pressure and specific enthalpy

cp_ph

Specific heat capacity at constant pressure as function of pressure and specific enthalpy

beta_props_ph

Isobaric expansion coefficient as function of pressure and specific enthalpy

beta_ph

Isobaric expansion coefficient as function of pressure and specific enthalpy

kappa_props_ph

Isothermal compressibility factor as function of pressure and specific enthalpy

kappa_ph

Isothermal compressibility factor as function of pressure and specific enthalpy

velocityOfSound_props_ph

Speed of sound as function of pressure and specific enthalpy

velocityOfSound_ph

isentropicExponent_props_ph

Isentropic exponent as function of pressure and specific enthalpy

isentropicExponent_ph

Isentropic exponent as function of pressure and specific enthalpy

ddph_props

Density derivative by pressure

ddph

Density derivative by pressure

ddhp_props

Density derivative by specific enthalpy

ddhp

Density derivative by specific enthalpy

waterBaseProp_pT

Intermediate property record for water (p and T preferred states)

rho_props_pT

Density as function or pressure and temperature

rho_pT

Density as function or pressure and temperature

h_props_pT

Specific enthalpy as function or pressure and temperature

h_pT

Specific enthalpy as function or pressure and temperature

h_pT_der

Derivative function of h_pT

rho_pT_der

Derivative function of rho_pT

s_props_pT

Specific entropy as function of pressure and temperature

s_pT

Temperature as function of pressure and temperature

cv_props_pT

Specific heat capacity at constant volume as function of pressure and temperature

cv_pT

Specific heat capacity at constant volume as function of pressure and temperature

cp_props_pT

Specific heat capacity at constant pressure as function of pressure and temperature

cp_pT

Specific heat capacity at constant pressure as function of pressure and temperature

beta_props_pT

Isobaric expansion coefficient as function of pressure and temperature

beta_pT

Isobaric expansion coefficient as function of pressure and temperature

kappa_props_pT

Isothermal compressibility factor as function of pressure and temperature

kappa_pT

Isothermal compressibility factor as function of pressure and temperature

velocityOfSound_props_pT

Speed of sound as function of pressure and temperature

velocityOfSound_pT

Speed of sound as function of pressure and temperature

isentropicExponent_props_pT

Isentropic exponent as function of pressure and temperature

isentropicExponent_pT

Isentropic exponent as function of pressure and temperature

waterBaseProp_dT

Intermediate property record for water (d and T preferred states)

h_props_dT

Specific enthalpy as function of density and temperature

h_dT

Specific enthalpy as function of density and temperature

h_dT_der

Derivative function of h_dT

p_props_dT

Pressure as function of density and temperature

p_dT

Pressure as function of density and temperature

p_dT_der

Derivative function of p_dT

s_props_dT

Specific entropy as function of density and temperature

s_dT

Temperature as function of density and temperature

cv_props_dT

Specific heat capacity at constant volume as function of density and temperature

cv_dT

Specific heat capacity at constant volume as function of density and temperature

cp_props_dT

Specific heat capacity at constant pressure as function of density and temperature

cp_dT

Specific heat capacity at constant pressure as function of density and temperature

beta_props_dT

Isobaric expansion coefficient as function of density and temperature

beta_dT

Isobaric expansion coefficient as function of density and temperature

kappa_props_dT

Isothermal compressibility factor as function of density and temperature

kappa_dT

Isothermal compressibility factor as function of density and temperature

velocityOfSound_props_dT

Speed of sound as function of density and temperature

velocityOfSound_dT

Speed of sound as function of density and temperature

isentropicExponent_props_dT

Isentropic exponent as function of density and temperature

isentropicExponent_dT

Isentropic exponent as function of density and temperature

hl_p

Compute the saturated liquid specific h(p)

hv_p

Compute the saturated vapour specific h(p)

sl_p

Compute the saturated liquid specific s(p)

sv_p

Compute the saturated vapour specific s(p)

rhol_T

Compute the saturated liquid d(T)

rhov_T

Compute the saturated vapour d(T)

rhol_p

Compute the saturated liquid d(p)

rhov_p

Compute the saturated vapour d(p)

dynamicViscosity

Compute eta(d,T) in the one-phase region

thermalConductivity

Compute lambda(d,T,p) in the one-phase region

surfaceTension

Compute sigma(T) at saturation T

isentropicEnthalpy

Isentropic specific enthalpy from p,s (preferably use dynamicIsentropicEnthalpy in dynamic simulation!)

isentropicEnthalpy_props

isentropicEnthalpy_der

Derivative of isentropic specific enthalpy from p,s

dynamicIsentropicEnthalpy

Isentropic specific enthalpy from p,s and good guesses of d and T

Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

Package description:

This package provides high accuracy physical properties for water according to the IAPWS/IF97 standard. 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.

The original documentation of the IAPWS/IF97 steam properties can freely be distributed with computer implementations, so for curious minds the complete standard documentation is provided with the Modelica properties library. The following documents are included (in directory Modelica/Resources/Documentation/Media/Water/IF97documentation):

  • IF97.pdf The standards document for the main part of the IF97.
  • Back3.pdf The backwards equations for region 3.
  • crits.pdf The critical point data.
  • meltsub.pdf The melting- and sublimation line formulation (in IF97_Utilities.BaseIF97.IceBoundaries)
  • surf.pdf The surface tension standard definition
  • thcond.pdf The thermal conductivity standard definition
  • visc.pdf The viscosity standard definition

Package contents

  • Package BaseIF97 contains the implementation of the IAPWS-IF97 as described in IF97.pdf. The explicit backwards equations for region 3 from Back3.pdf are implemented as initial values for an inverse iteration of the exact function in IF97 for the input pairs (p,h) and (p,s). The low-level functions in BaseIF97 are not needed for standard simulation usage, but can be useful for experts and some special purposes.
  • Function water_ph returns all properties needed for a dynamic control volume model and properties of general interest using pressure p and specific entropy enthalpy h as dynamic states in the record ThermoProperties_ph.
  • Function water_ps returns all properties needed for a dynamic control volume model and properties of general interest using pressure p and specific entropy s as dynamic states in the record ThermoProperties_ps.
  • Function water_dT returns all properties needed for a dynamic control volume model and properties of general interest using density d and temperature T as dynamic states in the record ThermoProperties_dT.
  • Function water_pT returns all properties needed for a dynamic control volume model and properties of general interest using pressure p and temperature T as dynamic states in the record ThermoProperties_pT. Due to the coupling of pressure and temperature in the two-phase region, this model can obviously only be used for one-phase models or models treating both phases independently.
  • Function hl_p computes the liquid specific enthalpy as a function of pressure. For overcritical pressures, the critical specific enthalpy is returned
  • Function hv_p computes the vapour specific enthalpy as a function of pressure. For overcritical pressures, the critical specific enthalpy is returned
  • Function sl_p computes the liquid specific entropy as a function of pressure. For overcritical pressures, the critical specific entropy is returned
  • Function sv_p computes the vapour specific entropy as a function of pressure. For overcritical pressures, the critical specific entropy is returned
  • Function rhol_T computes the liquid density as a function of temperature. For overcritical temperatures, the critical density is returned
  • Function rhol_T computes the vapour density as a function of temperature. For overcritical temperatures, the critical density is returned
  • Function dynamicViscosity computes the dynamic viscosity as a function of density and temperature.
  • Function thermalConductivity computes the thermal conductivity as a function of density, temperature and pressure. Important note: Obviously only two of the three inputs are really needed, but using three inputs speeds up the computation and the three variables are known in most models anyways. The inputs d,T and p have to be consistent.
  • Function surfaceTension computes the surface tension between vapour and liquid water as a function of temperature.
  • Function isentropicEnthalpy computes the specific enthalpy h(p,s,phase) in all regions. The phase input is needed due to discontinuous derivatives at the phase boundary.
  • Function dynamicIsentropicEnthalpy computes the specific enthalpy h(p,s,,dguess,Tguess,phase) in all regions. The phase input is needed due to discontinuous derivatives at the phase boundary. Tguess and dguess are initial guess values for the density and temperature consistent with p and s. This function should be preferred in dynamic simulations where good guesses are often available.

Version Info and Revision history

  • First implemented: July, 2000 by Hubertus Tummescheit for the ThermoFluid Library with help from Jonas Eborn and Falko Jens Wagner
  • Code reorganization, enhanced documentation, additional functions: December, 2002 by Hubertus Tummescheit and moved to Modelica properties library.
Author: Hubertus Tummescheit,
Modelon AB
Ideon Science Park
SE-22370 Lund, Sweden
email: hubertus@modelon.se

Wolfram Language

In[1]:=
SystemModel["Modelica.Media.Water.IF97_Utilities"]
Out[1]:=