Tag Archives: verification

Ein effizienter semi-impliziter Subgrid-Ansatz für Strömungen mit freier Oberfläche auf hierarchischen Gittern

F.W. Platzek, G.S. Stelling, J.A. Jankowski, R. Patzwahl and J.D. Pietrzak

German Abstract: Es wird eine neue Modellierstrategie zur Effizienzsteigerung rechenintensiver Simulationen von Flüssen vorgestellt. Der Ansatz kombiniert einen semi-impliziten Subgrid-Ansatz zur Berücksichtigung von hochaufgelösten Geländeinformationen auf gröberen Netzen mit einer auf Hierarchischen-Netzen basierenden Strategie. Continue reading

An efficient semi-implicit subgrid method for free-surface flows on hierarchical grids

F.W. Platzek, G.S. Stelling, J.A. Jankowski, R. Patzwahl and J.D. Pietrzak

Abstract: We present a new modelling strategy for improving the efficiency of computationally intensive flow problems in environmental free-surface flows. The approach combines a recently developed semi-implicit subgrid method with a hierarchical grid solution strategy. Continue reading

Verification and validation of the parallel UnTRIM

Jacek A. Jankowski. Verification and validation of the parallel UnTRIM, 5th UnTRIM Workshop, Trento, 19-21 May 2008.

A new UnTRIM version has been released (see Casulli 2008), featuring better data locality, improved interpolations in the advection scheme and, the most important, a radically new mass-conservative iterative approach to drying and wetting treatment based on Newton iterations with a proven convergence. In the presentation, detailed issues detected during the verification and validation of the refreshed MPI-parallel “2009” version of UnTRIM are presented, treated and resolved. Continue reading

Further developments of UnTRIM: parallel implementation and its verification

Jacek A. Jankowski. Further developments of UnTRIM: parallel implementation and its verification, ISEH V – IAHR Fifth International Symposium on Environmental Hydraulics, 2007, Tempe, Arizona, USA.

This presentation is complementary to the contributed conference paper. It is a summary of all stages of the development of the parallel version of UnTRIM applying the domain decomposition method and message passing (MPI): Continue reading

Further developments of UnTRIM: parallel implementation and its verification

J.A. Jankowski

Abstract. This contribution deals with further developments of UnTRIM, an unstructured-grid, three-dimensional, semi-implicit finite difference finite volume model for the shallow water equations (Casulli, 2002). Attractive numerical properties of the method like its robustness due to the unlimited stability and successes in practical applications spawned efforts aimed at making the available code fit for the high performance computing in order to address larger, complex problems in hydraulic engineering. Continue reading