IAPWS95 (version 1.2.4)

pTD: Pressure, Function of Temperature and Density

Description

The function pTD(T,D,digits=9) returns the water pressure, p [ MPa ], for given Temp [K] and D [kg/m3], returning also an error message, if any error occur.

Usage

pTD(Temp, D, digits = 9)

Value

The Pressure: p [ MPa ] and an Error Message (if an error occur: errorCodes)

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.

Examples

Temp <- 500.
D <- 838.025
p <- pTD(Temp,D)
p

Temp <- 647.096
D <- 322.
p <- pTD(Temp,D)
p