2 research outputs found
Geometry-Driven Detection, Tracking and Visual Analysis of Viscous and Gravitational Fingers
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.Comment: Published at IEEE Transactions on Visualization and Computer Graphic
Visual Analysis of Two-Phase Flow Displacement Processes in Porous Media
We present the visual analysis of our novel parameter study of porous media
experiments, focusing on gaining a better understanding of drainage processes
on the micro-scale. We analyze the temporal evolution of extracted
characteristic values, and discuss how to directly compare experiments that
exhibit processes at different temporal scales due to varying boundary and
physical conditions. To enable spatio-temporal analysis, we introduce a new
abstract visual representation showing which paths through the porous media
were occupied to what extent, e.g., allowing for classification into viscous
and capillary regimes. This joint work of porous media experts and
visualization researchers yields new insights regarding immiscible two-phase
flow on the micro-scale toward the overarching goal of characterizing flow
based on boundary conditions and physical fluid properties