Equations of State Based on Hybrid Data Sets - A Combined Approach for the Development of Fundamental Equations of State and of Accurate Molecular Models

• Applicants: Professor Dr.-Ing. Roland Span; Professor Dr.-Ing. Jadran Vrabec
• Subject Area: Technical Thermodynamics
• Term: from 2010 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 175415355

This project aims at the development of fundamental equations of state (EOS) for pure fluids based on hybrid data sets, consisting of data from molecular simulation and experiment. Additionally, molecular models will be optimized with the help of EOS. In the first project phase, it was shown for the following fluids that the approach is in principle feasible: Lennard-Jones (LJ) truncated and shifted fluid, LJ fluid, neon, argon, krypton, xenon and cyclohexane. Entirely based on simulation data, preliminary EOS were developed. The simulation tool ms2 was extended by implementing derivatives of the Helmholtz energy up to the third order. In addition, the power of optimizing molecular model parameters by fitting them to experimental data with the help of an EOS based on molecular simulation data was shown. Exemplarily, xenon and cyclohexane were studied. In the second project phase, the optimization of molecular model parameters will be regarded for more complex fluids. Thereby, the LJ parameters as well as polar moments, angles or distances between interaction sites will be considered. New EOS based on hybrid data both from simulation and experiment will be developed for several fluids, i.e. argon, krypton, xenon, cyclohexane, methanol, formic acid and carbon dioxide.

• DFG Programme: Research Grants