Thermodynamic Documentation Set
This folder collects topic-specific documentation for using NeqSim’s thermodynamic, PVT, and physical property capabilities. Each page is intended to be self-contained while pointing to related guides so you can jump directly to the workflows you need.
Package Structure
thermo/
├── system/ # Fluid system implementations (58 EoS classes)
├── phase/ # Phase types and calculations (62 classes)
├── component/ # Component properties (65 classes)
├── mixingrule/ # Mixing rules for EoS
└── characterization/ # Plus fraction characterization
Subpackage Documentation
| Subpackage | Description | Documentation |
|---|---|---|
| system | Equations of state implementations | system/README.md |
| phase | Phase modeling (gas, liquid, solid, asphaltene) | phase/README.md |
| component | Component property calculations | component/README.md |
| mixingrule | Binary interaction parameters | mixingrule/README.md |
| characterization | Plus fraction and asphaltene characterization | characterization/README.md |
Guide Contents
Core Guides
- Thermodynamic Models Guide: Comprehensive overview of all thermodynamic models in NeqSim, including equations of state, CPA, reference equations (GERG-2008, EOS-CG), activity coefficient models, electrolyte models, and the auto-select feature. Covers theory, usage, and model selection guidelines.
- Fluid Creation Guide: Comprehensive guide to creating fluids in NeqSim, including all available equations of state, mixing rules, and model selection guidelines.
- Mixing Rules Guide: Detailed documentation on mixing rules, including mathematical formulations, binary interaction parameters, and usage examples for different applications.
- Flash Calculations Guide: Comprehensive documentation of flash calculations available via ThermodynamicOperations, including TP, PH, PS, VU flashes, saturation calculations, and hydrate equilibria.
- Hydrate Models Guide: Comprehensive documentation of gas hydrate thermodynamic models, including van der Waals-Platteeuw theory, Structure I/II hydrates, CPA and PVTsim implementations, and inhibitor modeling.
- Electrolyte CPA Model: Detailed documentation of the electrolyte CPA model, including Fürst electrostatic contributions, validation data, and usage examples.
Database Documentation
- Component Database Guide: Detailed documentation of the COMP pure component parameters database, including parameter descriptions, units, and links to thermodynamic models.
- INTER Table Guide: Detailed documentation of the INTER binary interaction parameters database, including column reference for all EoS, CPA, Huron-Vidal, Wong-Sandler, and NRTL parameters.
Reference Documentation
- Mathematical Models: Equations of state, activity-coefficient formulations, and transport correlations available in NeqSim.
- GERG-2008 and EOS-CG: Detailed guide to the reference equations of state for natural gas and CCS applications.
Application Guides
- Thermodynamic Workflows: How to set up systems, select models, and perform common equilibrium calculations.
- PVT and Fluid Characterization: Building realistic fluid descriptions, including heavy-end handling and lab-data reconciliation.
- Thermodynamic Operations: Flash calculations, phase envelopes, and other process-centric operations.
- Physical Properties: Density, viscosity, surface tension, and transport-property calculations.
Each document favors short, reproducible code snippets using the Java API so the same ideas transfer to other supported languages (Python/Matlab) with minor syntax changes.