# Theory PagesΒΆ

In these pages we provide detailed theory for the various simulation capacities in PFLOTRAN-OGS.

- The Mathematical Formulation of GAS_WATER
- The Mathematical Formulation of TOIL_IMS
- The Mathematical Formulation of the Black Oil Model
- The Mathematical Formulation of the Solvent Todd-Longstaff Model
- The Mathematical Formulation of the Simple Todd-Longstaff Model
- Solving the Flow Equations
- Fluid component Properties
- Soil Compressibility Model
- The Characteristic Curves Smoother
- The Well Model