[Sedullo]

I need to write a report for my master thesis and I would like to describe the solver used (in my case buoyantBoussinesqPimpleFoam), writing all the equations solved by the solver.
In the solver folder all the solvers are described, but it is not so clear to me what are all the equations solved, since they are written in an unclear way.
Basically I am looking, if exists, for a document where all the equations are written and where I can find a clear description of the utilities of each solver, the User Guide is
too synthetic.
Thanks for the help!