[cfbaptista]

Standard OpenFOAM solvers are complete applications. This implies they do everything: read configuration files, initialize case and (for each time step) solve equations and write out data. This makes it difficult to embed an OpenFOAM solver into a 3rd party solver in a flexible manner.

I would like to know how to rewrite a standard OpenFOAM solver as a C++ class. By defining variables that need to remain in RAM as properties of the class and by defining actions (e.g. set boundary conditions, perform single time step, write out data) as methods of the class, I can instruct OpenFOAM to do what I want whenever I want.

My final objective is to rewrite pisoFoam as a C++ solver class for external flow cases (e.g. airfoil simulations). This class should contain methods to do at least the following:

1. Set Dirichlet boundary conditions for the velocity field on the numerical boundary
2. Perform a single time step

Can someone help me identify which variables I need to define as properties, or point me to documentation/tutorials dealing with similar things?

ps: Doing it the other way around (e.g. embedding the 3rd party solver inside OpenFOAM) is, unfortunately, not an option.