Geometry-Driven Detection, Tracking and Visual Analysis of Viscous and Gravitational Fingers

TL;DR

This paper introduces a geometric approach for detecting and analyzing the evolution of viscous and gravitational fingers in 3D fluid flow data, providing detailed insights into their dynamics beyond traditional density thresholding methods.

Contribution

It presents a novel geometric detection method, skeletonization, and a tracking graph to analyze finger growth, branching, merging, and splitting over time.

Findings

Effective geometric detection of fingers in 3D scalar fields

Spatio-temporal analysis of finger evolution and branching

Validated usefulness through feedback from earth scientists

Abstract

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.