Geometry-Driven Detection, Tracking and Visual Analysis of Viscous and Gravitational Fingers
This work addresses the need for detailed geometric analysis of fingering instabilities in fluid mechanics and hydrogeology, offering a domain-specific incremental improvement over previous thresholding methods.
The paper tackled the problem of detecting and analyzing viscous and gravitational fingers in 3D scalar fields, proposing a ridge voxel detection method and geometric-glyph tracking to study finger evolution, with feedback from earth scientists confirming its usefulness.
Viscous and gravitational flow instabilities cause a displacement front to break up into finger-like fluids. The detection and evolutionary analysis of these fingering instabilities are critical in multiple scientific disciplines such as fluid mechanics and hydrogeology. However, previous detection methods of the viscous and gravitational fingers are based on density thresholding, which provides limited geometric information of the fingers. The geometric structures of fingers and their evolution are important yet little studied in the literature. In this work, we explore the geometric detection and evolution of the fingers in detail to elucidate the dynamics of the instability. We propose a ridge voxel detection method to guide the extraction of finger cores from three-dimensional (3D) scalar fields. After skeletonizing finger cores into skeletons, we design a spanning tree based approach to capture how fingers branch spatially from the finger skeletons. Finally, we devise a novel geometric-glyph augmented tracking graph to study how the fingers and their branches grow, merge, and split over time. Feedback from earth scientists demonstrates the usefulness of our approach to performing spatio-temporal geometric analyses of fingers.