iapws95_sat: IAPWS-95 Formulation in the Saturation Region

In iapws: Formulations of the International Association for the Properties of Water and Steam

IAPWS-95 Formulation in the Saturation Region

Description

Compute thermodynamic and transport properties of water and steam along the saturated line according to the IAPWS formulation 1995.

Usage

iapws95_sat(what, p, t)

Arguments

what	a character vector listing the output properties. See Details for available properties.
t	a numeric vector giving the temperature values in K.
p	a numeric vector giving the pressure values in MPa.

Details

The available properties for what are:

• "f": the specific free energy in kJ/kg.

• "g": the specific Gibbs enthalpy in kJ/kg.

• "u": the specific internal energy in kJ/kg.

• "h": the specific enthalpy in kJ/kg.

• "s": the specific entropy in kJ/K/kg.

• "t": the temperature in K.

• "p": the pressure in MPa.

• "v": the specific volume in m^3/kg.

• "rho": the mass density in kg/m^3.

• "cv": the specific isochoric heat capacity in kJ/K/kg.

• "cp": the specific isobaric heat capacity in kJ/K/kg.

• "alpha": the expansion coefficient in 1/K

• "beta": the pressure coefficient in MPa/K.

• "kappat": the isothermal compressibility in 1/MPa.

• "w": the speed of sound in m/s.

• "eta": the dynamic viscosity in \muPa.s.

• "lambda": the thermal conductivity in mW/K/m.

Only one of t or p is needed. If both arguments are given, p is ignored.

Value

A numeric array of dimension c(n, length(what), 2L) with n the length of either p or t. The last dimension indicate the physical state ("liquid" or "gas").

Note

Computing several properties in a single call may be more efficient than separately because most of the computation time is shared.

Author(s)

Jonathan Debove

References

International Association for the Properties of Water and Steam, IAPWS R6-95(2018), Revised Release on the IAPWS Formulation 1995 for the Thermodynamic Properties of Ordinary Water Substance for General and Scientific Use.

Examples

# IAPWS-95 Tab. 8
tab <- iapws95_sat(c("p", "rho", "h", "s"), t = c(275, 450, 625))
format(tab, scientific = TRUE, digits = 9)

iapws documentation built on June 8, 2025, 11:14 a.m.