Tag Archives: free surface flows

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

Efficient river modelling applying subgrid technology (UnTRIM2)

Two subsequent presentations on the 13th UnTRIM Workshop 2016 with the same title Efficient river modelling applying subgrid technology (UnTRIM2), the first part concerning concept and grids, presented by Regina Patzwahl, and the second part concerning results, presented by Jacek A. Jankowski. 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

Intel Many Integrated Core (MIC) architecture and the UnTRIM code

Intel Many Integrated Core (MIC) architecture and the UnTRIM code, 11th UnTRIM Workshop, Trento, 19-21 May 2014.

The presentation describes the results of an investigation concerning the potential of porting the UnTRIM2 code (with subgrids, see Casulli and Stelling 2010) to the Intel MIC processors, the trade mark name Xeon Phi. Continue reading

Accurate vertical profiles of turbulent flow in z-layer models

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

Abstract. Three-dimensional hydrodynamic z-layer models, which are used for simulating the flow in rivers, estuaries, and oceans, suffer from an inaccurate and often discontinuous bottom shear stress representation, due to the staircase bottom. We analyze the governing equations and clearly show the cause of the inaccuracies. Based on the analysis, we present a new method that significantly reduces the errors and the grid dependency of the results. Continue reading