phi0DD {IAPWS95} | R Documentation |
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)
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.
Value
The Second D Derivative of Ideal-gas part of the Helmholtz Energy: phi0DD and an Error Message (if an error occur: errorCodes)
Examples
D <- 838.025
phi_0 <- phi0DD(D)
phi_0