
<!-- README.md is generated from README.Rmd. Please edit that file -->

# IAPWS95

The goal of IAPWS95 is to provide thermodynamic and transport properties
of Water for general and scientifc use.

IAPWS95 calculates thermodynamic and transport properties of water as
function of different combinations of Temperature, Density, Pressure,
Enthalphy and Entropy. It is dedicated to scientists and engineers who
analyze thermal and hydraulic experimental data or are involved with
projects and equipment development, like turbines or nuclear reactors.
This Vignette shows too few examples, but each function is documented
with examples. The name IAPWS95 comes from the “IAPWS Formulation 1995
for the Thermodynamic Properties of Ordinary Water Substance for General
and Scientific Use”, a formulation developed by “The International
Association for the Properties of Water and Steam”, revised in 2014.
<https://iapws.org> IAPWS-95 formulation is based on the fundamental
equation of Helmholtz free energy as a function of temperature and
density, f = f(T, ρ). Other thermodynamic properties are obtained by
differentiation and algebraic manipulation without the use of any other
information. IAPWS-95 defines accurately the thermodynamic properties of
the fluid phases of ordinary water substance, with complete
thermodynamic consistency among these properties, over a wide range of
states (pressures up to 1000 MPa and temperatures from the melting and
sublimation temperatures to 1273 K). In this package the lower
temperature limit is the triple point temperature, 273.16 K. The
definition of properties includes those on the liquid–vapor equilibrium
line. The transport properties programmed were based on different IAPWS
Releases: “Release on the IAPWS Formulation 2011 for the Thermal
Conductivity of Ordinary Water Substance”; “Release on the IAPWS
Formulation 2008 for the Viscosity of Ordinary Water Substance”;
“Revised Release on Surface Tension of Ordinary Water Substance” (2014).
The melting pressure was based on the “Revised Release on the Pressure
along the Melting and Sublimation Curves of Ordinary Water Substance”
(2011). The vapor pressure is based on Wagner and Pruß equation (1993),
valid from the triple point temperature (273.16 K) to the critical
temperature (647.096 K).

## Installation

You can install the development version of IAPWS95 from
[GitHub](https://github.com/) with:

``` r
# install.packages("devtools")
# devtools::install_github("shivaway/IAPWS95")
```

## Example

This is a basic example which shows you how to obtain the water pressure
as Function of Temperature and Pressure:

``` r
## basic example code: Pressure as Function of Temperature and Density
T <- 500.
D <- 838.025
p <- IAPWS95::pTD(T,D)
#> [1] 10.0003858
p
```

    ## [1] 10.00039

``` r
#> [1] 10.0003858
```
