Tag Archives: UnTRIM

Mathematical Model UnTRIM – MPI Version Manual

Jacek A. Jankowski

Abstract. This document is aimed to provide the user of the MPI version of UnTRIM with necessary information for the installation, compilation and especially execution of the software. 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

Parallel streamline tracking for UnTRIM

Jacek A. Jankowski. Parallel streamline tracking for UnTRIM, 4th UnTRIM Workshop, Trento, 7-9 May 2007.

The parallel streamline tracking algorithm for the domain decomposition method applied in the MPI version of UnTRIM, is described in detail. The streamline tracking is the integral part of the semi-Lagrangian method of characteristics, being one of the most robust methods for the non-linear momentum advection, working also for larger Courant numbers. The method is however awkward to parallelise in the framework of the point-to-point communication typical for the domain decomposition method. Continue reading