IEEE VIS 2024 Content: Topological Separation of Vortices

Topological Separation of Vortices

Adeel Zafar - University of Houston, Houston, United States

Zahra Poorshayegh - University of Houston, Houston, United States

Di Yang - University of Houston, Houston, United States

Guoning Chen - University of Houston, Houston, United States

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Room: Bayshore I

2024-10-17T15:15:00ZGMT-0600Change your timezone on the schedule page
2024-10-17T15:15:00Z
Exemplar figure, described by caption below
This figure illustrates the steps of the proposed topological separation method. (a) shows a vortical region extracted using a specific value of ?2, along with the critical points of the minimal join tree. (b) displays the contour tree-based segmentation of the region using the extracted minimal join tree. (c) depicts the use of �layering� to assign appropriate segmentation IDs to the segment (red) associated with the maximum. (d) shows the region being separated into exactly two vortices (green and blue). (e) illustrates the process of ensuring the validity of the split by computing the vorticity lines in the vicinity of the split."
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Keywords

Fluid flow, vortices, vortex topology

Abstract

Vortices and their analysis play a critical role in the understanding of complex phenomena in turbulent flows. Traditional vortex extraction methods, notably region-based techniques, often overlook the entanglement phenomenon, resulting in the inclusion of multiple vortices within a single extracted region. Their separation is necessary for quantifying different types of vortices and their statistics. In this study, we propose a novel vortex separation method that extends the conventional contour tree-based segmentation approach with an additional step termed “layering”. Upon extracting a vortical region using specified vortex criteria (e.g., λ2), we initially establish topological segmentation based on the contour tree, followed by the layering process to allocate appropriate segmentation IDs to unsegmented cells, thus separating individual vortices within the region. However, these regions may still suffer from inaccurate splits, which we address statistically by leveraging the continuity of vorticity lines across the split boundaries. Our findings demonstrate a significant improvement in both the separation of vortices and the mitigation of inaccurate splits compared to prior methods.