FWF - Darwish - Coupling Strategies for Compr. Flow Algorithms in OpenFOAM

This proposal aims to carry out research on coupled finite volume algorithms for compressible fluid flows. The resulting approach is expected to be fast, robust and accurate at a time. The applicant has already established extensive know-how in the field of equation coupling of incompressible flows that shall be extended to compressible flows. In comparison to standard segregated approaches he showed that considerable gains, both in terms of robustness and convergence speed can be made. Since a 5x5xN system of equations arises from coupling the compressible flow variables for 3-D flows (N being the number of finite volume cells), a very fast linear multi-grid solver that scales linearly with the number of cells is necessary to overcome the disadvantage of having 25 times more entries in the matrix to be solved. Hence one part of the proposed project shall be the elaboration and the implementation of a suitable preconditioning and agglomeration strategy for such a solver. The second part of the project shall focus on the elaboration and implementation of coupled transition and turbulence models that are also expected to considerably improve the robustness and convergence speed compared to standard segregated approaches. As a development framework the open source CFD library OpenFOAM® was selected to serve as a platform for collaborative work since it enriches and facilitates the exchange with other researchers.