phirT: First Derivative of the Residual-Gas Part of the...

In IAPWS95: Thermophysical Properties of Water and Steam

First Derivative of the Residual-Gas Part of the Dimensionless Helmholtz Energy Equation with respect to Temperature, Function of Temperature and Density

Description

The function phirT(Temp,D,digits=9) returns the First Derivative of the Residual-Gas Part of the Dimensionless Helmholtz Energy Equation with respect to Temp, for given Temp [K] and D [kg/m3].

Usage

phirT(Temp, D, digits = 9)

Arguments

Temp	Temperature [ K ]
D	Density [ kg m-3 ]
digits	Digits of results (optional)

Details

This function calls a Fortran DLL that solves the Helmholtz Energy Equation. in accordance with the Revised Release on the IAPWS Formulation 1995 for the Thermodynamic Properties of Ordinary Water Substance for General and Scientific Use (June 2014) developed by the International Association for the Properties of Water and Steam, http://www.iapws.org/relguide/IAPWS-95.html. It is valid from the triple point to the pressure of 1000 MPa and temperature of 1273.

Value

The First Derivative of the Residual-Gas Part of the Dimensionless Helmholtz Energy Equation with respect to Temp: phirT, and an Error Message (if an error occur: errorCodes)

Examples

Temp <- 500.
D <- 838.025
phir_T <- phirT(Temp,D)
phir_T

IAPWS95 documentation built on Sept. 11, 2023, 5:11 p.m.