phirDT: Second Derivative of the Residual-Gas Part of the...

In IAPWS95: Thermophysical Properties of Water and Steam

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

Description

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

Usage

phirDT(Temp, D, digits)

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

Examples

Temp <- 500.
D <- 838.025
phir_DT <- phirDT(Temp,D)
phir_DT

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