Particle-based Vortex Core Line Tracking Taking into Account Vortex Dynamics

The Investigation of the temporal behavior of coherent structures is a complex process. Particularly when vortices and their temporal change of strength or spatial extents are considered, a pure tracking of vortical structures is insufficient. The exploration of such properties makes it necessary to take into account the interaction between individual coherent structures, also called vortex dynamics. In this paper, we propose a framework which allows the tracking of segmented vortex structures taking into account vortex dynamics. Our framework is based upon an existing vortex core line detection and vortex segmentation implementation which is extended as follows: (1) vortex tracking: the core lines are considered as connected particles which are integrated along a given time-dependent vector field and tested against overlapping with the core lines of the following time step; (2) consideration of vortex dynamics: during the tracking process of a selected vortex, and for each time step, the vortex with the highest effect is computed; then the time step of the strongest perturbation tp is determined; (3) tracking of the perturbing vortices: starting at tp, the vortex structures with the highest effect are tracked along time to provide information about their temporal evolution; (4) visualization: vortical regions are represented by segmented λ2 isosurfaces which are highlighted using color coding and bounding boxes in the case they are tracked.