filename     : p_Bau02.pdf
entry        : inproceedings
pages        : 525-529
year         : 2002
title        : A Case Study in Selective Visualization of Unsteady 3D Flow
author       : D. Bauer, R. Peikert, M. Sato, M. Sick
booktitle    : Proceedings of IEEE Visualization '02
editor       : Robert Moorhead, Markus Gross, Kenneth I. Joy
publisher    : IEEE Computer Society Press
language     : english
month        : October
keywords     : Flow Visualization, Selective Visualization, Particle Tracing, Sobol points, Regions of Interest, ROI, vortex rope, vortex hull, scalar fields, cavitation regions
abstract     : In this case study, we explore techniques for the purpose of visualizing isolated flow structures in time-dependent data. Our primary industrial application is the visualization of the vortex rope, a rotating helical structure which builds up in the draft tube of a water turbine. The vortex rope can be characterized by high values of normalized helicity, which is a scalar field derived from the given CFD velocity data. In two related applications, the goal is to visualize the cavitation regions near the runner blades of a Kaplan turbine and a water pump, respectively. Again, the flow structure of interest can be defined by a scalar field, namely by low pressure values. We propose a particle seeding scheme based on quasi-random numbers, which minimizes visual artifacts such as clusters or patterns. By constraining the visualization to a region of interest, occlusion problems are reduced and storage efficiency is gained.