## 12.7. Real Gas Property (RGP) File Format

The following provides a description of the real gas property (.rgp) file format. The .rgp file enables you to input your own specialized real fluid properties into a CFD calculation. The .rgp file can be used in conjunction with all models available in CFX.

An .rgp file can contain properties for any number of pure component materials. However, the .rgp files supplied with CFX only contain one pure component each. Once you load the CCL for a particular equation of state, all materials that use that equation of state are loaded into CFX-Pre.

If you want to maintain your own .rgp file that contains multiple pure components, then each new material in the .rgp file begins with the `$$$<component>` access key, where `<component>` is the name of the material. Any number of these access keys may exist in the file.

For each fluid associated with an access key, several blocks of information are available, including parameter definition, superheat table, and saturation table information. However, because many calculations do not require all of this information, a less complete set of property information can be included in the .rgp file. In this release of CFX, only the dry superheated vapor model is supported, corresponding to `MODEL=3` in the .rgp file. Other settings of this parameter are ignored by the CFX-Solver, so all the saturation data that would normally be read when using the non-equilibrium (`MODEL=1`) or equilibrium (`MODEL=2`) models will be ignored. This means that the `$$SAT_TABLE` section does not have to exist under a `$$$Database` access key, that the `SUPERCOOLING` parameter can be zero and that only the `$$SUPER_TABLE` section is necessary.

Release 18.2 - © ANSYS, Inc. All rights reserved.