Heinrich Werner

Numerical simulation of turbulent flow over surface-mounted obstacles with sharp edges and corners

Abstract Results from numerical simulations of turbulent flow around a surface-mounted cube and over a surface-mounted square rib are presented. The first problem is treated by solving the Reynolds equations together with the standard k − ϵ turbulence model, for 0° and 45° orientation of the flow obstacle, in uniform and boundary layer incident flow. The second problem is solved by applying the concept of large-eddy simulation. In both calculation concepts, sufficient spatial resolution is essential to get satisfying agreement with experimental data in the critical flow regimes, e.g. above the top face of the flow obstacles. The computations based on large-eddy simulation are very expensive but can provide excellent agreement of the numerical results with the experimental data for the second-order statistics.

Implementation of nonlinear boundary conditions in finite element analysis

Abstract In finite element analysis sometimes special boundary conditions such as no-tension, friction contact or other nonlinear types occur. A family of boundary condition elements is presented. Based on the Winkler assumption for elastic foundations the stiffness matrix for two and three dimensional isoparametric elements is developed which account for linear or nonlinear bedding of structures.

FEINSET — Finite-Elemente-Programm mit interaktiver Benutzungsoberfläche, automatischer Fehlerabschätzung und adaptiver Netzverbesserung

Mit FEINSET wird eine neue Generation der bewahrten Programmkette SET (Structural Engineering and Tunneling) vorgestellt. FEINSET zeichnet sich durch die folgenden neuen Eigenschaften aus: n n1. n nWorkstationlosung fur UNIX-Rechner n n n n n2. n nmenugesteuerte Methodenauswahl, Datenverwaltung und Ergebnisprasentation am Arbeitsplatz n n n n n3. n ngrafisch-interaktive Systemgenerierung mit CAD-konformen Hilfsmitteln und Datenstrukturen n n n n n4. n nadaptives FE-Programm fur Platten-, Scheiben- und Potentialprobleme mit Fehlerabschatzung und automatischer Netzverbesserung nach der h-p-Methode (HIPSET) n n n n n5. n nfarbige Ergebnisdarstellungen auf verformten, raumlichen Strukturen (COLSET) n n n n n6. n nSchnittstellen zu den CAD-Programmen ALLPLOT/ALLFEM n n n n n7. n nGrundgrafik GKS mit DXF-Schnittstelle n n n n n8. n nIndexsequentielle Struktur und Verwaltung der Datenbasis

A Graph-Theoretical Approach to a Plotter Pen Touring Problem

A graph-theoretical approach to the problem of optimizing the sequence of plot commands is presented. The mesh to be drawn is described by a graph which is extended to an Euler graph. In the extended graph an Euler tour is found, which is associated with the tour of the pen. A typical application of the algorithm is that of plotting meshes as they appear in finite element problems.