phi0DD: Second Derivative of the Ideal-Gas Part of the Dimensionless Helmholtz Energy Equation
with respect to Density, Function of Density
Description
The function phi0DD(D,digits=9) returns the Second Derivative of the
Ideal-gas part of the dimensionless Helmholtz Energy Equation for a given D [kg/m3].
Usage
phi0DD(D, digits = 9)
Value
The Second D Derivative of Ideal-gas part of the Helmholtz Energy: phi0DD and an Error
Message (if an error occur: errorCodes)
Arguments
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.