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
	ThermoFluidSpecial Protected
	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

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

Intermediate release notes during development

Currently the Events/noEvents switch is only implemented for p-h states. Only after testing that implementation, it will be extended to dT.