○ July 8 (Mon)
Time |
10:30-11:30 |
Speaker |
Jens Kasten
Leipzig University, Germany |
Title |
Feature-Based Analysis of Time-Dependent Flow Fields |
Abstract |
Visualization of fluid flows can be divided in different areas of research. First, direct visualization
uses advanced tools from computer graphics to depict the flow in an easily comprehensible
image. In contrast, feature-based analysis helps to focus on the important structures of the flow.
For time-dependent flow fields, the concept of Lagrangian coherent structures (LCSs) became
famous in the recent years. Typically, these structures are associated with the Finite-time
Lyapnuov Exponent (FTLE). This feature indicator connects LCSs to manifolds of strong particle
separation and convergence. However, also other structures such as vortices are often
connected to LCSs. Here, the acceleration magnitude can help to identify areas of strong swirling
motion. In my talk, I will present methods to extract both features. A special focus is placed on
using robust combinatorial methods for feature extraction [1,2,3]. I will present applications to
different time-dependent two-dimensional flow fields. An overview of the presented tools can be
found in [4].
[1] J. Reininghaus, D. Gunther, I. Hotz, S. Prohaska, and H.-C. Hege. TADD: A computational
framework for data analysis using discrete Morse theory. In Proceedings International Congress
on Mathematical Software 2010, pages 198.208, 2010.
[2] H. Edelsbrunner, J. Harer, and A. Zomorodian: Hierarchical Morse Complexes for Piecewise
Linear 2-manifolds. In Proceedings Symposium on Computational Geometry 2001, pages 70-79.
[3] U. Bauer, M. Kerber, and J. Reininghaus. PHAT: Persistent Homology Algorithm Toolbox. http://phat.googlecode.com
[4] J. Kasten: Lagrangian Feature Extraction in Two-dimensional Unsteady Flows. PhD thesis, FU
Berlin, 2012.
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PDF file is available here. |
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