Jacek A. Jankowski. UnTRIM parallelization with message passing, 3rd UnTRIM Workshop, Trento, 15-17 May 2006.
This is a second part of the UnTRIM parallelisation project presentations — for the background, see the previous post. The most important issue addressed so far concerns absolving a number of stringent verification tests applied for checking the parallel implementation correctness as well as the user steering of the model. Continue reading
Jacek A. Jankowski. UnTRIM parallelization with message passing, 2nd UnTRIM Workshop, Sirmione, 23-25 May 2005.
The main ideas behind the parallelisation of UnTRIM applying the domain decomposition method and the message passing (MPI) are discussed. The issues concerning the mesh partitioning, point-to-point communication over the mesh-overlapping areas (halos) for purely triangular and mixed (triangles and quadrangles) meshes and the problems connected with the Lagrangian advection scheme are thoroughly described. Continue reading
Jacek A. Jankowski and Andreas Malcherek.
Developing an advection scheme for Telemac-2D based on the 2nd order characteristics method, 8th Telemac User Club, Chatou, 15-16 November 2001.
One of the best method of improving the accuracy of the advection scheme based on method of characterictics is to improve the interpolation of advected variables on the feet of the traced-back characteristic curves. The results of applying the second order interpolation in broader element patches are compared with the presently applied single-element linear interpolation and the SUPG method. Continue reading
Jacek A. Jankowski
PhD thesis Abstract
An algorithm for solution of three-dimensional Navier-Stokes equations for incompressible free surface flows is developed. A decoupled algorithm based on the fractional step (operator-splitting) technique is applied. The solution is obtained in subsequent stages treating equations split into parts having well-defined mathematical properties, so that the most adequate methods for a given differential operator type can be used. The decoupled algorithm structure, which does not use the continuity equation explicitly, allows application of equal-order linear interpolation functions for all variables. The applied reference element type, a prism with six nodes and linear interpolation functions, is a compromise between the exactness of the interpolation, model complexity and computational cost. The finite difference method is applied for the time discretisation and the computational domain variability is taken into account by a standard sigma-mesh structure which is well suited to most geophysical applications. Continue reading
Ein nicht-hydrostatisches Modell für Strömungen mit freier Oberfläche, Promotionsvortrag, 12. November 1998, Institut für Strömungsmechanik und Elektronisches Rechnen im Bauwesen der Universität Hannover. Continue reading