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freesteam / News: Recent posts

Freesteam 2.0 released

Freesteam 2.0 has now been released. This is a complete rewrite of
freesteam in plain C, removing all the complicated C++ template-based
code. This was done to make freesteam faster and leaner, as well as to
allow the single resulting DLL/shared library to be easily reusable
across multiple C++ compilers.

The code supports property calculations for (p,T), (p,h), (p,s), (p,v),
(T,s), and (T,x) over regions 1-4 of the IAPWS IF-97 revised release.
Calculation of p, T, h, s, cp, cv, v, rho, u, x and w are supported.
Calculation of thermal conductivity and dynamic viscosity have also
been implemented using correlations from other IAPWS releases. C, Python and ASCEND APIs are still provided, but they have changed significantly from the 0.8.1 version.... read more

Posted by John Pye 2010-01-24

Freesteam rewrite in C underway

A rewrite of freesteam into the C language is underway, as an attempt to simplify the codebase and make it more portable and more maintainable.

Currently, the (p,h) property pair is implemented, as well as all the forwards and most of the backwards equations for regions 1,2,3 and 4. Iterative solving routines for other property pairs are in the works, but ironically these are rather more difficult to implement without the shorthand of C++ template syntax. Hopefully a nice simple approach can be found.... read more

Posted by John Pye 2009-03-03

Freesteam migrating to Subversion

The freesteam CVS repository will be disabled shortly and a new subversion repository used in its place. Once the SVN repository is available, please use that one.

Posted by John Pye 2008-06-25

Freesteam 0.8.1 release

This is a minor bugfix release of freesteam to
address a problem with compiling the sample code on
Windows. A missing '#include <math.h>' was added.

Some validation of the viscosity correlation
has also been performed, and some additional test
cases added to the Python test suite.

Posted by John Pye 2007-10-15

Freesteam 0.8 released

This release contains important fixes to the thermal conductivity correlation and also fixes an error in the interpolation formula for density in the two-phase region (ie Region 4). Both these fixes were in response to bugs reported by Kestell Laurie.

There is also now a little script 'freesteam-config' that you can use to help with linking to freesteam, in the style of "gcc `freesteam-config --cppflags --libs` myprog.cpp".... read more

Posted by John Pye 2007-09-25

Freesteam 0.7.2 released

This version provides freesteam as a shared library instead of as a static library. Support for the ASCEND modelling environment has also been improved, and the example C++ and Python scripts have been tested and documented a little better.

Posted by John Pye 2007-08-20

Website migrated to

The Freesteam website has been migrated from to the new location at .

If you have a link to the old webpage, please
update it, as the old server will soon be going

Posted by John Pye 2007-06-13

Freesteam 0.7.1 released

This version includes an example C++ program. For users of the Windows installer, there is an 'example code' entry in the start menu, including a README file to help you get start with linking again the freesteam library

There is also a README for Python users, and some more ASCEND language bindings have been added.

Posted by John Pye 2007-03-12

Freesteam 0.7 released

This version includes a Windows binary installer. A static library (.a), python bindings and library for use with ASCEND simulation environment are included.

Posted by John Pye 2007-01-18

Freesteam 0.6.2 released

This is a minor bugfix release for freesteam. It corrects an incorrect value in the conversion between psi and bar that may have affected Python users.

The release also includes some enhancements to bindings provided for the ASCEND modelling environment.

Posted by John Pye 2007-01-17

Code docs updated

The online code documentation for freesteam has been brought up to date with the 0.6.1 release.

For a sample page see:

The code docs are linked through from the side-bar on the freesteam homepage.

Posted by John Pye 2006-07-19

Freesteam 0.6.1 released

Freesteam is a C++ implementation of the IAPWS-IF97 and IAPWS-95 steam tables as published the International Association for the Properties of Water and Steam (IAPWS).

Freesteam lets you compute water and steam properties for a wide range of pressures and temperatures: you can specify the state of the steam in terms of a variety of combinations of 'known' properties, then freesteam will solve and allow you to query to find the values of the 'unknown' properties.... read more

Posted by John Pye 2006-07-07