## Software

Under the direction of Prof. Wagner (1975-2006), the Chair of Thermodynamics at Ruhr-Universität Bochum had dealt with research in the field of thermodynamic properties of fluid substances. Besides a number of highly accurate equations of state, which in many cases, have been considered as international references for the properties of the corresponding substance, an extensive set of algorithms for the calculation of thermodynamic properties from equations of state formulated in terms of the Helmholtz free energy have resulted from this work.

Extensive software packages have been developed during the past years, to make this modern way of easily calculating thermodynamic properties available for users in industry and research. These packages are customized for every individual field of application and are continuously further developed.

**Software FLUIDCAL for the calculation of thermodynamic properties for a great number of substances**

Software components are available for more than 70 substances. With this software, thermodynamic properties can be calculated easily and accurately.

**Software for the IAPWS-95 Formulation**

A comprehensive software package has been developed for the calculation of thermodynamic properties of water based on the scientific standard equation of state IAPWS-95.

**Software for the Industrial Formulation IAPWS-IF97**

An extensive software package has been developed for the calculation of thermodynamic properties of water and steam based on the Industrial Formulation IAPWS-IF97. This package allows the user to apply the new industrial standards for the calculation of power plants and a number of other different technical applications in an easy way.

**Software for the reference equation of state GERG-2008 for natural gases and other mixtures**

For the reference equation of state GERG-2008, a comprehensive and userfriendly software package is available. The software enables to calculate several thermodynamic properties in the homogeneous gas, liquid, and supercritical regions and allows to carry out VLE calculations at arbitrary mixture conditions where the prior knowledge of the number of phases (one or two) is not required. The VLE calculation options include different flash options as well as phase envelope, dew point, and bubble point calculations.