For the open-source users,
I have just updated the FreeFluidsModelica library. It now includes media based on equations of state, so capable for working both below and over the critical temperature.
The media is implemented using an external object for the substances data, and external functions for calculation. Therefore, it is not compatible with the new frontend of OpenModelica, that doesn’t implement external functions yet, but it is compatible with the old frontend. It has been tested with OpenModelica 1.14.1 on Windows. I expect, but I am not sure, compatibility with Linux platform also.
The media uses multiparameter (Seltzmann and Wagner type) equations of state (EOS), and also PCSAFT and cubic type ones. You can switch between them and compare the obtained results if you want. The quality of the thermodynamic calculations depend on the used EOS, being very high if multiparameter type is used. Compared with other applications like CoolProp, the calculation very close to the critical point is weak, as no special technique, as for example cubic splines, is used. The calculation of transport properties is also done using phase specific correlations with pressure correction, instead of multiphase temperature-density dependent functions. On the positive side, it is very easy to use, and you have PCSAFT and cubic EOS for the products for which no reference equation of state is available. You will find several tests inside the packages.
You can download it here