TY - JOUR A1 - Kasten, Jens A1 - Reininghaus, Jan A1 - Hotz, Ingrid A1 - Hege, Hans-Christian T1 - Two-Dimensional Time-Dependent Vortex Regions Based on the Acceleration Magnitude JF - IEEE Transactions on Visualization and Computer Graphics Y1 - 2011 VL - 17 IS - 12 SP - 2080 EP - 2087target ER - TY - CHAP A1 - Reininghaus, Jan A1 - Günther, David A1 - Hotz, Ingrid A1 - Prohaska, Steffen A1 - Hege, Hans-Christian T1 - TADD: A Computational Framework for Data Analysis Using Discrete Morse Theory T2 - Mathematical Software - ICMS 2010 Y1 - 2010 U6 - https://doi.org/10.1007/978-3-642-15582-6_35 VL - 6327 SP - 198 EP - 208 PB - Springer ER - TY - GEN A1 - Zobel, Valentin A1 - Reininghaus, Jan A1 - Hotz, Ingrid T1 - Visualization of Two-Dimensional Symmetric Tensor Fields Using the Heat Kernel Signature T2 - Topological Methods in Data Analysis and Visualization III Y1 - 2013 SP - 249 EP - 262 CY - Davis, CA, USA ER - TY - JOUR A1 - Kasten, Jens A1 - Reininghaus, Jan A1 - Hotz, Ingrid A1 - Hege, Hans-Christian A1 - Noack, Bernd A1 - Daviller, Guillaume A1 - Morzyński, Marek T1 - Acceleration feature points of unsteady shear flows JF - Archives of Mechanics N2 - A framework is proposed for extracting features in 2D transient flows, based on the acceleration field to ensure Galilean invariance. The minima of the acceleration magnitude, i.e. a superset of the acceleration zeros, are extracted and discriminated into vortices and saddle points --- based on the spectral properties of the velocity Jacobian. The extraction of topological features is performed with purely combinatorial algorithms from discrete computational topology. The feature points are prioritized with persistence, as a physically meaningful importance measure. These features are tracked in time with a robust algorithm for tracking features. Thus a space-time hierarchy of the minima is built and vortex merging events are detected. The acceleration feature extraction strategy is applied to three two-dimensional shear flows: (1) an incompressible periodic cylinder wake, (2) an incompressible planar mixing layer and (3) a weakly compressible planar jet. The vortex-like acceleration feature points are shown to be well aligned with acceleration zeros, maxima of the vorticity magnitude, minima of pressure field and minima of λ2. Y1 - 2016 VL - 68 IS - 1 SP - 55 EP - 80 ER - TY - GEN A1 - Kasten, Jens A1 - Reininghaus, Jan A1 - Hotz, Ingrid A1 - Hege, Hans-Christian A1 - Noack, Bernd A1 - Daviller, Guillaume A1 - Morzyński, Marek T1 - Acceleration feature points of unsteady shear flows N2 - A framework is proposed for extracting features in 2D transient flows, based on the acceleration field to ensure Galilean invariance. The minima of the acceleration magnitude, i.e. a superset of the acceleration zeros, are extracted and discriminated into vortices and saddle points --- based on the spectral properties of the velocity Jacobian. The extraction of topological features is performed with purely combinatorial algorithms from discrete computational topology. The feature points are prioritized with persistence, as a physically meaningful importance measure. These features are tracked in time with a robust algorithm for tracking features. Thus a space-time hierarchy of the minima is built and vortex merging events are detected. The acceleration feature extraction strategy is applied to three two-dimensional shear flows: (1) an incompressible periodic cylinder wake, (2) an incompressible planar mixing layer and (3) a weakly compressible planar jet. The vortex-like acceleration feature points are shown to be well aligned with acceleration zeros, maxima of the vorticity magnitude, minima of pressure field and minima of λ2. T3 - ZIB-Report - 15-65 Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-58397 SN - 1438-0064 ER - TY - GEN A1 - Günther, David A1 - Reininghaus, Jan A1 - Prohaska, Steffen A1 - Weinkauf, Tino A1 - Hege, Hans-Christian ED - Peikert, Ronny ED - Hauser, Helwig ED - Carr, Hamish T1 - Efficient Computation of a Hierarchy of Discrete 3D Gradient Vector Fields T2 - Topological Methods in Data Analysis and Visualization II Y1 - 2012 U6 - https://doi.org/10.1007/978-3-642-23175-9_2 SP - 15 EP - 29 PB - Springer ER - TY - GEN A1 - Kasten, Jens A1 - Reininghaus, Jan A1 - Oberleithner, Kilian A1 - Hotz, Ingrid A1 - Noack, Bernd A1 - Hege, Hans-Christian T1 - Flow over a Cavity – Evolution of the Vortex Skeleton Y1 - 2010 PB - Visualization at 28th Annual Gallery of Fluid Motion exhibit, held at the 63th Annual Meeting of the American Physical Society, Division of Fluid Dynamics (Long Beach, CA, USA, November 21-23, 2010). ER -