We should reiterate from the outset that OpenFOAM is a C++ library used primarily to create executables, known as applications. OpenFOAM is distributed with a large set of precompiled applications but users also have the freedom to create their own or modify existing ones. Applications are split into two main categories:
- that are each designed to solve a specific problem in computational continuum mechanics;
- that perform simple pre-and post-processing tasks, mainly involving data manipulation and algebraic calculations.
OpenFOAM is divided into a set of precompiled libraries that are dynamically linked during compilation of the solvers and utilities. Libraries such as those for physical models are supplied as source code so that users may conveniently add their own models to the libraries. This chapter gives an overview of solvers, utilities and libraries, their creation, modification, compilation and execution.