OpenFOAM offers a large range of methods and models to simulate turbulence, through its TurbulenceModels library. The library supports: models for constant and variable density, e.g. for incompressible and compressible flows, inclusion of buoyancy terms, etc; models for single phase and multiphase flows; configuration of sources and constraints in case input files. It includes the following types of turbulence simulation:
- Reynolds-average simulation (RAS), also known as Reynolds-averaged Navier-Stokes (RANS): The governing equations are solved in ensemble-averaged form, including appropriate models for the effect of turbulence. See the list of RAS models for more information.
- Large eddy simulation (LES): Large turbulent structures in the flow are resolved by the governing equations, while the effect of the sub-grid scales (SGS) are modelled. The scale separation is obtained by applying a filter to the governing equations which also influences the form of the SGS models. The list of LES models contains information about models, LES filters and filter width functions.
- Detached eddy simulation (DES): Hybrid method that treats near-wall regions with a RAS approach and the bulk flow with an LES approach. DES models are found in the list of DES models.
- Direct numerical simulation (DNS): Resolves all scales of turbulence by solving the Navier-Stokes equations numerically without any turbulence modelling. DNS simulations can be performed in OpenFOAM using the dnsFoamsolver.