The PPADD project is based on a finite elements multilevel scheme for the solution of non-linear PDEs. The terms describing the non-linear interactions between the fine and coarse level are costly to compute, and can be frozen during a time that can be estimated from the behavior of the solution. This multilevel scheme is the mathematical basis for decoupling the solver from the mesh refinement. Moreover, the solution of each approximate non-linear equation uses domain decomposition methods based on dual Schur's complement.
The global architecture is composed of three main modules : the Solver, the Domain Manager and the Visualization Interface. Currently, only the Domain Manager and one version of the Solver are implemented. Besides visualization facilities, future versions will allow to configure the Solver for multiple numerical solvers.