Pathline predicates and unsteady flow structures

Interest in renewable, green, and sustainable energy has risen sharply in recent years. The use of marine turbines to extract kinetic energy from the tidal current is gaining popularity. CFD modeling is carried out to investigate the surrounding flow behavior and thus develop effective marine turbine systems. However, visualizing the simulation results remains a challenging task for engineers. In this paper, we develop, explore and present customized visualization techniques in order to help engineers gain a fast overview and intuitive insight into the flow past the marine turbine. The system exploits multiple-coordinated information-assisted views of the CFD simulation data. Our application consists of a tabular histogram, velocity histogram, parallel coordinate plot, streamline plot and spatial views. Information-based streamline seeding is used to investigate the behavior of the flow deemed interesting to the engineer. Specialized, application-specific information based on swirling flow is derived and visualized in order to evaluate turbine blade design. To demonstrate the usage of our system, a selection of specialized case scenarios designed to answer the core questions brought out by engineers is described. We also report feedback on our system from CFD experts researching marine turbine simulations.

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“…We also note the related work of Shi et al [25] and Salzbrunn et al [26] on the use of pathlines for flow visualization.…”

Section: Related Workmentioning

confidence: 99%

Visualization of flow past a marine turbine: the information-assisted search for sustainable energy

Peng

Zhao

Nicholas

et al. 2013

Comput. Visual Sci.

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“…We adopted this method for the visualization of properties of the charge flow lines derived from the charge trajectories. Another way to deal with large set of lines is to use filtering methods using line predicates as proposed by Salzbrunn et al [25]. Most of the above described methods are however not appropriate for the rendering of the original charge trajectories, which are stochastic in their nature and non-smooth.…”

Section: Related Workmentioning

confidence: 99%

Visual Analysis of Stochastic Trajectory Ensembles in Organic Solar Cell Design

et al. 2017

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Abstract:We present a visualization system for analyzing stochastic particle trajectory ensembles, resulting from Kinetic Monte-Carlo simulations on charge transport in organic solar cells. The system supports the analysis of such trajectories in relation to complex material morphologies. It supports the inspection of individual trajectories or the entire ensemble on different levels of abstraction. Characteristic measures quantify the efficiency of the charge transport. Hence, our system led to better understanding of ensemble trajectories by: (i) Capturing individual trajectory behavior and providing an ensemble overview; (ii) Enabling exploration through linked interaction between 3D representations and plots of characteristics measures; (iii) Discovering potential traps in the material morphology; (iv) Studying preferential paths. The visualization system became a central part of the research process. As such, it continuously develops further along with the development of new hypothesis and questions from the application. Findings derived from the first visualizations, e.g., new efficiency measures, became new features of the system. Most of these features arose from discussions combining the data-perspective view from visualization with the physical background knowledge of the underlying processes. While our system has been built for a specific application, the concepts translate to data sets for other stochastic particle simulations.

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“…The definition by Salzbrunn et al [35] describes a line predicate P as a Boolean function mapping a point p of a pathline P to true or false:…”

Section: Extension Of Line Predicatesmentioning

confidence: 99%

“…Line Predicates: Line predicates, introduced by Salzbrunn et al [35], provide an alternative approach to the flow field analysis. Several scalar criteria are computed for each point of an integral line and used for subsequent filtering.…”

Section: Related Workmentioning

confidence: 99%

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Semi-Automatic Vortex Extraction in 4D PC-MRI Cardiac Blood Flow Data using Line Predicates

Köhler¹,

Gasteiger²,

Preim³

et al. 2013

IEEE Trans. Visual. Comput. Graphics

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This indicates an improperly closing aortic valve and supports the decision whether or not to implant an artificial valve.Abstract-Cardiovascular diseases (CVD) are the leading cause of death worldwide. Their initiation and evolution depends strongly on the blood flow characteristics. In recent years, advances in 4D PC-MRI acquisition enable reliable and time-resolved 3D flow measuring, which allows a qualitative and quantitative analysis of the patient-specific hemodynamics. Currently, medical researchers investigate the relation between characteristic flow patterns like vortices and different pathologies. The manual extraction and evaluation is tedious and requires expert knowledge. Standardized, (semi-)automatic and reliable techniques are necessary to make the analysis of 4D PC-MRI applicable for the clinical routine. In this work, we present an approach for the extraction of vortex flow in the aorta and pulmonary artery incorporating line predicates. We provide an extensive comparison of existent vortex extraction methods to determine the most suitable vortex criterion for cardiac blood flow and apply our approach to ten datasets with different pathologies like coarctations, Tetralogy of Fallot and aneurysms. For two cases we provide a detailed discussion how our results are capable to complement existent diagnosis information. To ensure real-time feedback for the domain experts we implement our method completely on the GPU.

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Pathline predicates and unsteady flow structures

Cited by 59 publications

References 20 publications

Visualization of flow past a marine turbine: the information-assisted search for sustainable energy

Visualization of flow past a marine turbine: the information-assisted search for sustainable energy

Visual Analysis of Stochastic Trajectory Ensembles in Organic Solar Cell Design

Semi-Automatic Vortex Extraction in 4D PC-MRI Cardiac Blood Flow Data using Line Predicates

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