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  • 1.
    Behrendt, Benjamin
    et al.
    Department of Simulation and Graphics, University of Magdeburg, Germany.
    Engelke, Wito
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Berg, Philipp
    Department of Fluid Dynamics and Technical Flows, University of Magdeburg, Germany.
    Beuing, Oliver
    Institute of Neuroradiology, University Hospital Magdeburg, Germany.
    Preim, Bernhard
    Department of Simulation and Graphics, University of Magdeburg, Germany.
    Hotz, Ingrid
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Saalfeld, Sylvia
    Department of Simulation and Graphics, University of Magdeburg, Germany.
    Evolutionary Pathlines for Blood Flow Exploration in Cerebral Aneurysms2019Inngår i: Eurographics Workshop on Visual Computing for Biology and Medicine / [ed] Kozlíková, Barbora and Linsen, Lars and Vázquez, Pere-Pau and Lawonn, Kai and Raidou, Renata Georgia, The Eurographics Association , 2019Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Blood flow simulations play an important role for the understanding of vascular diseases, such as aneurysms. However, analysis of the resulting flow patterns, especially comparisons across patient groups, are challenging. Typically, the hemodynamic analysis relies on trial and error inspection of the flow data based on pathline visualizations and surface renderings. Visualizing too many pathlines at once may obstruct interesting features, e.g., embedded vortices, whereas with too little pathlines, particularities such as flow characteristics in aneurysm blebs might be missed. While filtering and clustering techniques support this task, they require the pre-computation of pathlines densely sampled in the space-time domain. Not only does this become prohibitively expensive for large patient groups, but the results often suffer from undersampling artifacts. In this work, we propose the usage of evolutionary algorithms to reduce the overhead of computing pathlines that do not contribute to the analysis, while simultaneously reducing the undersampling artifacts. Integrated in an interactive framework, it efficiently supports the evaluation of hemodynamics for clinical research and treatment planning in case of cerebral aneurysms. The specification of general optimization criteria for entire patient groups allows the blood flow data to be batch-processed. We present clinical cases to demonstrate the benefits of our approach especially in presence of aneurysm blebs. Furthermore, we conducted an evaluation with four expert neuroradiologists. As a result, we report advantages of our method for treatment planning to underpin its clinical potential.  

  • 2.
    Cencetti, Michele
    et al.
    ALTEC Spa, Italy.
    Musso, Ivano
    ALTEC Spa, Italy.
    Bar, Christian
    Thales Alenia Space, Italy.
    Basso, Valter
    Thales Alenia Space, Italy.
    Schneegans, Simon
    DLR, Germany.
    Engelke, Wito
    DLR, Germany.
    Gerndt, Andreas
    DLR, Germany.
    Garcia, Arturo
    University of Salford, England.
    CROSS DRIVE: A Collaborative Virtual Reality Workplace for Space Science Data Exploitation and Rover Operations Engineering2016Inngår i: SECESA 2016, 2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The CrossDrive Project develops Distributed and Collaborative Infrastructure based on advanced Immersive Virtual Reality tools for the analysis and management of Scientific Data and Operational Activities of planetary spacecraft. The Collaborative Workspace encompasses advanced technological solutions for central storage processing, 3D visualisation and Virtual Presence in Immersive Virtual Reality environments, to support Space Data Analysis and Space Operations. Science objectives are share and correlate Atmospheric data, analysis and simulations based on the actual main Mars’ satellites (MEX and MRO); compare and correlate data for Geology and Geodesy; benchmark satellite and ground based Mars atmospheric measurements.

  • 3. Bestill onlineKjøp publikasjonen >>
    Engelke, Wito
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Exploring the Invisible: FINDING STRUCTURE IN SCIENTIFIC DATA2022Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    In this thesis, I present contributions towards the aim of understanding flow-related scientific data sets by communicating relation, properties, and structure. The individual papers are contributions to three different areas. First, real-world visualization challenges with domain specific tasks. The individual applications are ranging from analyzing transport behavior in a centrifugal pump, to visualization of the impact of volcano eruptions and their atmospheric aftermath, and studying circulation dynamics and eddy movements in the ocean currents of the Red Sea. Although the three individual publications target different domains, they share common demands. Furthermore, the experience shows that combining and adapting different visualization techniques to support experts is essential for these scenarios. Second, technical visualization research with a strong focus on geometry-based, interactive, and explorative techniques. In this area a new type of particle system and a novel geometry-based flow visualization technique based on evolutionary algorithms are presented. With both approaches, areas of interest can be highlighted in a semi-automatic fashion by facilitating user-defined importance measures. Lastly, a method for decoupling definition and tracking of features. Here, the development of a fast but flexible method for defining and tracking cyclonic features in pressure fields using a solid and robust mathematical basis is presented. The initial theoretical work is discussed in context of its practical applications by pointing to relevant follow-up publications.

    The experience from real-world visualization tasks shows that understanding and gaining insight of scientific data with the help of visualization is an interactive, explorative, and non-linear process. Here, different methods must be combined and adapted such that they complement each other. Through this practice, relation, properties, and structure can be revealed, and a mental model can be created.

    From the real-world visualization challenges and the contributions in research, demands on techniques and their embedding in a visualization toolkit can be derived. Here, the ideal software is flexible, adaptable, and allows for interactive exploration. Furthermore, the process is benefiting from a semi-automatic approach guiding the domain expert during analysis. These aspects are used as guidelines for the implementation and development work associated with the contributions of this thesis and are presented in a dedicated Chapter.

    Delarbeid
    1. Atmospheric Impact of Volcano Eruptions
    Åpne denne publikasjonen i ny fane eller vindu >>Atmospheric Impact of Volcano Eruptions
    Vise andre…
    2014 (engelsk)Inngår i: Proceedings IEEE SciVis 2014, Publication Server of Zuse Institute Berlin (ZIB) , 2014Konferansepaper, Oral presentation only (Fagfellevurdert)
    Abstract [en]

    The analysis of data that captures volcanic eruptions and their atmospheric aftermath plays an important role for domain experts to gain a deeper understanding of the volcanic eruption and their consequences for atmosphere, climate and air traffic. Thereby, one major challenge is to extract and combine the essential information, which is spread over various, mostly sparse data sources. This requires a careful integration of each data set with its strength and limitations. The sparse, but more reliable measurement data is mainly used to calibrate the more dense simulation data. This work combines a collection of visualization approaches into an exploitative framework. The goal is to support the domain experts to build a complete picture of the situation. But it is also important to understand the individual data sources, the wealth of their information and the quality of the simulation results. All presented methods are designed for direct interaction with the data from different perspectives rather than the sole generation of some final images.

    sted, utgiver, år, opplag, sider
    Publication Server of Zuse Institute Berlin (ZIB), 2014
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-152358 (URN)
    Konferanse
    IEEE VIS 2014,9-14 November, Paris, France
    Tilgjengelig fra: 2018-10-30 Laget: 2018-10-30 Sist oppdatert: 2022-03-25bibliografisk kontrollert
    2. Autonomous Particles for Interactive Flow Visualization
    Åpne denne publikasjonen i ny fane eller vindu >>Autonomous Particles for Interactive Flow Visualization
    2019 (engelsk)Inngår i: Computer graphics forum (Print), ISSN 0167-7055, E-ISSN 1467-8659, nr 1, s. 248-259Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    We present an interactive approach to analyse flow fields using a new type of particle system, which is composed of autonomous particles exploring the flow. While particles provide a very intuitive way to visualize flows, it is a challenge to capture the important features with such systems. Particles tend to cluster in regions of low velocity and regions of interest are often sparsely populated. To overcome these disadvantages, we propose an automatic adaption of the particle density with respect to local importance measures. These measures are user defined and the systems sensitivity to them can be adjusted interactively. Together with the particle history, these measures define a probability for particles to multiply or die, respectively. There is no communication between the particles and no neighbourhood information has to be maintained. Thus, the particles can be handled in parallel and support a real‐time investigation of flow fields. To enhance the visualization, the particles' properties and selected field measures are also used to specify the systems rendering parameters, such as colour and size. We demonstrate the effectiveness of our approach on different simulated vector fields from technical and medical applications.

    sted, utgiver, år, opplag, sider
    John Wiley & Sons, 2019
    Emneord
    flow visualization, scientific visualization, visualization, real-time rendering, Visualization Human-centered computing: Visualization application domains–Scientific Visualization
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-151724 (URN)10.1111/cgf.13528 (DOI)000462660600016 ()
    Konferanse
    EuroVis 2018, Conference on Visualization 4-8 June, Czech Republic
    Merknad

    Funding agencies: Stiftelsen for Strategisk Forskning Sweden (SSF) [BD15-0082]; Excellence Center at Linkoping and Lund in Information Technology (ELLIIT); Swedish e-Science Research Centre (SeRC)

    Tilgjengelig fra: 2018-10-03 Laget: 2018-10-03 Sist oppdatert: 2022-03-25bibliografisk kontrollert
    3. Evolutionary Lines for Flow Visualization
    Åpne denne publikasjonen i ny fane eller vindu >>Evolutionary Lines for Flow Visualization
    2018 (engelsk)Inngår i: EuroVis 2018, 20th EG/VGTC Conference on Visualization, 4-8 June, Brno, Czech Republic / [ed] Jimmy Johansson and Filip Sadlo and Tobias Schreck, The Eurographics Association , 2018, s. 7-11Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    In this work we explore evolutionary algorithms for selected a visualization application. We demonstrate its potential using an example from flow visualization showing promising first results. Evolutionary algorithms, as guided search approach, find close-to-optimal solutions with respect to some fitness function in an iterative process using biologically motivated mechanisms like selection, mutation and recombination. As such, they provide a powerful alternative to filtering methods commonly used in visualization where the space of possible candidates is densely sampled in a pre-processing step from which the best candidates are selected and visualized. This approach however tends to be increasingly inefficient with growing data size or expensive candidate computations resulting in large pre-processing times. We present an evolutionary algorithm for the problem of streamline selection to highlight features of interest in flow data. Our approach directly optimizes the solution candidates with respect to a user selected fitness function requiring significantly less computations. At the same time the problem of possible under-sampling is solved since we are not tied to a preset resolution. We demonstrate our approach on the well-known flow around an obstacle as case with a two-dimensional search space. The blood flow in an aneurysm serves as an example with a three-dimensional search space. For both, the achieved results are comparable to line filtering approaches with much less line computations.

    sted, utgiver, år, opplag, sider
    The Eurographics Association, 2018
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-151725 (URN)10.2312/eurovisshort.20181070 (DOI)9783038680604 (ISBN)
    Konferanse
    EuroVis 2018, 20th EG/VGTC Conference on Visualization, 4-8 June, Brno, Czech Republic
    Tilgjengelig fra: 2018-10-03 Laget: 2018-10-03 Sist oppdatert: 2022-03-25
    4. Evolutionary Pathlines for Blood Flow Exploration in Cerebral Aneurysms
    Åpne denne publikasjonen i ny fane eller vindu >>Evolutionary Pathlines for Blood Flow Exploration in Cerebral Aneurysms
    Vise andre…
    2019 (engelsk)Inngår i: Eurographics Workshop on Visual Computing for Biology and Medicine / [ed] Kozlíková, Barbora and Linsen, Lars and Vázquez, Pere-Pau and Lawonn, Kai and Raidou, Renata Georgia, The Eurographics Association , 2019Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    Blood flow simulations play an important role for the understanding of vascular diseases, such as aneurysms. However, analysis of the resulting flow patterns, especially comparisons across patient groups, are challenging. Typically, the hemodynamic analysis relies on trial and error inspection of the flow data based on pathline visualizations and surface renderings. Visualizing too many pathlines at once may obstruct interesting features, e.g., embedded vortices, whereas with too little pathlines, particularities such as flow characteristics in aneurysm blebs might be missed. While filtering and clustering techniques support this task, they require the pre-computation of pathlines densely sampled in the space-time domain. Not only does this become prohibitively expensive for large patient groups, but the results often suffer from undersampling artifacts. In this work, we propose the usage of evolutionary algorithms to reduce the overhead of computing pathlines that do not contribute to the analysis, while simultaneously reducing the undersampling artifacts. Integrated in an interactive framework, it efficiently supports the evaluation of hemodynamics for clinical research and treatment planning in case of cerebral aneurysms. The specification of general optimization criteria for entire patient groups allows the blood flow data to be batch-processed. We present clinical cases to demonstrate the benefits of our approach especially in presence of aneurysm blebs. Furthermore, we conducted an evaluation with four expert neuroradiologists. As a result, we report advantages of our method for treatment planning to underpin its clinical potential.  

    sted, utgiver, år, opplag, sider
    The Eurographics Association, 2019
    Emneord
    Human-centered computing, Scientific visualization
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-184202 (URN)10.2312/vcbm.20191250 (DOI)978-3-03868-081-9 (ISBN)
    Konferanse
    VCBM 19: Eurographics Workshop on Visual Computing for Biology and Medicine
    Tilgjengelig fra: 2022-04-07 Laget: 2022-04-07 Sist oppdatert: 2022-04-07
    5. Topology-Based Feature Design and Tracking for Multi-center Cyclones
    Åpne denne publikasjonen i ny fane eller vindu >>Topology-Based Feature Design and Tracking for Multi-center Cyclones
    Vise andre…
    2021 (engelsk)Inngår i: Topological Methods in Data Analysis and Visualization VI: Theory, Applications, and Software / [ed] Ingrid Hotz, Talha Bin Masood, Filip Sadlo and Julien Tierny, Springer, 2021, s. 71-85Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    In this paper, we propose a concept to design, track, and compare application-specific feature definitions expressed as sets of critical points. Our work has been inspired by the observation that in many applications a large variety of different feature definitions for the same concept are used. Often, these definitions compete with each other and it is unclear which definition should be used in which context. A prominent example is the definition of cyclones in climate research. Despite the differences, frequently these feature definitions can be related to topological concepts.

    sted, utgiver, år, opplag, sider
    Springer, 2021
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-182268 (URN)10.1007/978-3-030-83500-2_5 (DOI)2-s2.0-85116754849 (Scopus ID)9783030834999 (ISBN)9783030835002 (ISBN)
    Forskningsfinansiär
    Swedish Foundation for Strategic Research, BD15-0082Swedish e‐Science Research CenterELLIIT - The Linköping‐Lund Initiative on IT and Mobile Communications
    Tilgjengelig fra: 2022-01-11 Laget: 2022-01-11 Sist oppdatert: 2022-09-01bibliografisk kontrollert
    Fulltekst (pdf)
    fulltext
    Download (png)
    presentationsbild
  • 4.
    Engelke, Wito
    et al.
    German Aerospace Center (DLR), Simulation and Software Technology, Baunschweig, Germany.
    Flatken, Markus
    German Aerospace Center - DLR, Germany.
    Garcia, Arturo
    The University of Salford, UK.
    Bar, Christian
    Thales Alenia Space, Italy.
    Gerndt, Andreas
    German Aerospace Center (DLR), Simulation and Software Technology, Germany.
    Scientific Visualization for Atmospheric Data Analysis in Collaborative Virtual Environments2016Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The three year European research project CROSS DRIVE (Collaborative Rover Operations and Planetary Science Analysis System based on Distributed Remote and Interactive Virtual Environments) started in January 2014. The research and development within this project is motivated by three use case studies: landing site characterization, atmospheric science and rover target selection.

    Currently the implementation for the second use case is in its final phase. Here, the requirements were generated based on the domain experts input and lead to development and integration of appropriate methods for visualization and analysis of atmospheric data. The methods range from volume rendering, interactive slicing, iso-surface techniques to interactive probing. All visualization methods are integrated in DLR’s Terrain Rendering application. With this, the high resolution surface data visualization can be enriched with additional methods appropriate for atmospheric data sets. This results in an integrated virtual environment where the scientist has the possibility to interactively explore his data sets directly within the correct context. The data sets include volumetric data of the martian atmosphere, precomputed two dimensional maps and vertical profiles. In most cases the surface data as well as the atmospheric data has global coverage and is of time dependent nature. Furthermore, all interaction is synchronized between different connected application  instances, allowing for collaborative sessions between distant experts.

    Fulltekst (pdf)
    Scientific Visualization for Atmospheric Data Analysis in Collaborative Virtual Environments
  • 5.
    Engelke, Wito
    et al.
    German Aerospace Center (DLR), Simulation and Software Technology, Germany.
    Garcia, Arturo
    The University of Salford, UK .
    Wolff, Robin
    German Aerospace Center (DLR), Simulation and Software Technology, Germany.
    Bar, Christian
    Thales Alenia Space, Italy.
    Fernando, Terrence
    The University of Salford, UK .
    Roberts, David
    The University of Salford, UK .
    Gerndt, Andreas
    German Aerospace Center (DLR), Simulation and Software Technology, Germany.
    Scientific Visualization for Space Science Data Analysis in Collaborative Virtual Environments2015Inngår i: Proceedings of IEEE SciVis 2015, Institute of Electrical and Electronics Engineers (IEEE), 2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The European research project CROSS DRIVE (Collaborative Rover Operations and Planetary Science Analysis System based on Distributed Remote and Interactive Virtual Environments) aims at developing an innovative collaborative workspace infrastructure enabling re- mote scientific and engineering experts to collectively analyze and interpret combined datasets using shared simulation tools. The three year project started in January 2014 and unites best European expertise in the fields of planetary research and Mars science, Virtual Reality (VR), atmospheric science and research as well as rover mission planning.

    Fulltekst (pdf)
    Scientific Visualization for Space Science Data Analysis in Collaborative Virtual Environments
  • 6.
    Engelke, Wito
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Hotz, Ingrid
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Evolutionary Lines for Flow Visualization2018Inngår i: EuroVis 2018, 20th EG/VGTC Conference on Visualization, 4-8 June, Brno, Czech Republic / [ed] Jimmy Johansson and Filip Sadlo and Tobias Schreck, The Eurographics Association , 2018, s. 7-11Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this work we explore evolutionary algorithms for selected a visualization application. We demonstrate its potential using an example from flow visualization showing promising first results. Evolutionary algorithms, as guided search approach, find close-to-optimal solutions with respect to some fitness function in an iterative process using biologically motivated mechanisms like selection, mutation and recombination. As such, they provide a powerful alternative to filtering methods commonly used in visualization where the space of possible candidates is densely sampled in a pre-processing step from which the best candidates are selected and visualized. This approach however tends to be increasingly inefficient with growing data size or expensive candidate computations resulting in large pre-processing times. We present an evolutionary algorithm for the problem of streamline selection to highlight features of interest in flow data. Our approach directly optimizes the solution candidates with respect to a user selected fitness function requiring significantly less computations. At the same time the problem of possible under-sampling is solved since we are not tied to a preset resolution. We demonstrate our approach on the well-known flow around an obstacle as case with a two-dimensional search space. The blood flow in an aneurysm serves as an example with a three-dimensional search space. For both, the achieved results are comparable to line filtering approaches with much less line computations.

    Fulltekst (pdf)
    Evolutionary Lines for Flow Visualization
  • 7.
    Engelke, Wito
    et al.
    Dept. Simulation and Software Technology - German Aerospace Center (DLR), Germany.
    Kuhn, Alexander
    Zuse Institute Berlin (ZIB), Germany.
    Flatken, Markus
    Dept. Simulation and Software Technology - German Aerospace Center (DLR), Germany.
    Chen, Fang
    Dept. Simulation and Software Technology - German Aerospace Center (DLR), Germany.
    Hege, Hans-Christian
    Zuse Institute Berlin (ZIB), Germany.
    Gerndt, Andreas
    Dept. Simulation and Software Technology - German Aerospace Center (DLR), GermanyDept. Simulation and Software Technology - German Aerospace Center (DLR), Germany.
    Hotz, Ingrid
    Dept. Simulation and Software Technology - German Aerospace Center (DLR), GermanyDept. Simulation and Software Technology - German Aerospace Center (DLR), Germany.
    Atmospheric Impact of Volcano Eruptions2014Inngår i: Proceedings IEEE SciVis 2014, Publication Server of Zuse Institute Berlin (ZIB) , 2014Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The analysis of data that captures volcanic eruptions and their atmospheric aftermath plays an important role for domain experts to gain a deeper understanding of the volcanic eruption and their consequences for atmosphere, climate and air traffic. Thereby, one major challenge is to extract and combine the essential information, which is spread over various, mostly sparse data sources. This requires a careful integration of each data set with its strength and limitations. The sparse, but more reliable measurement data is mainly used to calibrate the more dense simulation data. This work combines a collection of visualization approaches into an exploitative framework. The goal is to support the domain experts to build a complete picture of the situation. But it is also important to understand the individual data sources, the wealth of their information and the quality of the simulation results. All presented methods are designed for direct interaction with the data from different perspectives rather than the sole generation of some final images.

    Fulltekst (pdf)
    Atmospheric Impact of Volcano Eruptions
  • 8.
    Engelke, Wito
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Lawonn, Kai
    Department of Simulation and Graphics, University of Magdeburg, Germany / Institute for Computational Visualistics, University of Koblenz‐Landau, Germany.
    Preim, Bernhard
    Department of Simulation and Graphics, University of Magdeburg, Germany.
    Hotz, Ingrid
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Autonomous Particles for Interactive Flow Visualization2019Inngår i: Computer graphics forum (Print), ISSN 0167-7055, E-ISSN 1467-8659, nr 1, s. 248-259Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present an interactive approach to analyse flow fields using a new type of particle system, which is composed of autonomous particles exploring the flow. While particles provide a very intuitive way to visualize flows, it is a challenge to capture the important features with such systems. Particles tend to cluster in regions of low velocity and regions of interest are often sparsely populated. To overcome these disadvantages, we propose an automatic adaption of the particle density with respect to local importance measures. These measures are user defined and the systems sensitivity to them can be adjusted interactively. Together with the particle history, these measures define a probability for particles to multiply or die, respectively. There is no communication between the particles and no neighbourhood information has to be maintained. Thus, the particles can be handled in parallel and support a real‐time investigation of flow fields. To enhance the visualization, the particles' properties and selected field measures are also used to specify the systems rendering parameters, such as colour and size. We demonstrate the effectiveness of our approach on different simulated vector fields from technical and medical applications.

    Fulltekst (pdf)
    Autonomous Particles for Interactive Flow Visualization
  • 9.
    Engelke, Wito
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Masood, Talha Bin
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Beran, Jakob
    Department of Meteorology (MISU)Stockholm University, Stockholm, Sweden.
    Caballero, Rodrigo
    Department of Meteorology (MISU)Stockholm University, Stockholm, Sweden.
    Hotz, Ingrid
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Topology-Based Feature Design and Tracking for Multi-center Cyclones2021Inngår i: Topological Methods in Data Analysis and Visualization VI: Theory, Applications, and Software / [ed] Ingrid Hotz, Talha Bin Masood, Filip Sadlo and Julien Tierny, Springer, 2021, s. 71-85Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    In this paper, we propose a concept to design, track, and compare application-specific feature definitions expressed as sets of critical points. Our work has been inspired by the observation that in many applications a large variety of different feature definitions for the same concept are used. Often, these definitions compete with each other and it is unclear which definition should be used in which context. A prominent example is the definition of cyclones in climate research. Despite the differences, frequently these feature definitions can be related to topological concepts.

    Fulltekst (pdf)
    fulltext
  • 10.
    Garcia, Arturo S.
    et al.
    University of Salford Salford, Greater Manchester M5 4WT, UK.
    Roberts, David J.
    University of Salford Salford, Greater Manchester M5 4WT, UK.
    Fernando, Terrence
    University of Salford Salford, Greater Manchester M5 4WT, UK.
    Bar, Christian
    Thales Alenia Space Italia Strada Antica di Collegno 253 Turin, Italy.
    Wolff, Robin
    German Aerospace Center (DLR) Lilienthalplatz 7, D-38108 Braunschweig, Germany.
    Dodiya, Janki
    German Aerospace Center (DLR) Lilienthalplatz 7, D-38108 Braunschweig, Germany.
    Engelke, Wito
    German Aerospace Center (DLR) Lilienthalplatz 7, D-38108 Braunschweig, Germany.
    Gerndt, Andreas
    German Aerospace Center (DLR) Lilienthalplatz 7, D-38108 Braunschweig, Germany.
    A collaborative workspace architecture for strengthening collaboration among space scientists2015Inngår i: Proceedings of a meeting held 7-14 March 2015, Big Sky, Montana, USA., Institute of Electrical and Electronics Engineers (IEEE), 2015, s. 1133-1144Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Space exploration missions have produced large data of immense value, to both research and the planning and operating of future missions. However, current datasets and simulation tools fragment teamwork, especially across disciplines and geographical location. The aerospace community already exploits virtual reality for purposes including space tele-robotics, interactive 3D visualization, simulation and training. However, collaborative virtual environments are yet to be widely deployed or routinely used in space projects. Advanced immersive and collaborative visualization systems have the potential for enhancing the efficiency and efficacy of data analysis, simplifying visual benchmarking, presentations and discussions. We present preliminary results of the EU funded international project CROSS DRIVE, which develops an infrastructure for collaborative workspaces for space science and missions. The aim is to allow remote scientific and engineering experts to collectively analyze and interpret combined datasets using shared simulation tools. The approach is to combine advanced 3D visualization techniques and interactive tools in conjunction with immersive virtuality telepresence. This will give scientists and engineers the impression of teleportation from their respective buildings across Europe, to stand together on a planetary surface, surrounded by the information and tools that they need. The conceptual architecture and proposed realization of the collaborative workspace are described. ESA's planned ExoMars mission provides the use-case for deriving user requirements and evaluating our implementation.

  • 11.
    Gerndt, Andreas
    et al.
    German Aerospace Center (DLR), Simulation and Software Technology, Germany.
    Engelke, Wito
    German Aerospace Center (DLR), Simulation and Software Technology, Germany.
    Giuranna, Marco
    Instituto Nazionale di Astrofisica.
    Vandaele, Ann Carine
    Institut d'Aeronomie Spatiale de Belgique.
    Neary, Lori
    Institut d'Aeronomie Spatiale de Belgique.
    Aoki, Shohei
    Instituto Nazionale di Astrofisica.
    Kasaba, Yasumasa
    National University Corporation Tohoku University.
    Garcia, Arturo
    The University of Salford, UK.
    Fernando, Terrence
    The University of Salford, UK.
    Roberts, David
    The University of Salford, UK.
    CROSS DRIVE: A New Interactive and Immersive Approach for Exploring 3D Time-Dependent Mars Atmospheric Data in Distributed Teams2016Inngår i: American Astronomical Society, DPS meeting #48, id.220.31, 2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Atmospheric phenomena of Mars can be highly dynamic and have daily and seasonal variations. Planetary-scale wavelike disturbances, for example, are frequently observed in Mars' polar winter atmosphere. Possible sources of the wave activity were suggested to be dynamical instabilities and quasi-stationary planetary waves, i.e. waves that arise predominantly via zonally asymmetric surface properties. For a comprehensive understanding of these phenomena, single layers of altitude have to be analyzed carefully and relations between different atmospheric quantities and interaction with the surface of Mars have to be considered. The CROSS DRIVE project tries to address the presentation of those data with a global view by means of virtual reality techniques. Complex orbiter data from spectrometer and observation data from Earth are combined with global circulation models and high-resolution terrain data and images available from Mars Express or MRO instruments. Scientists can interactively extract features from those dataset and can change visualization parameters in real-time in order to emphasize findings. Stereoscopic views allow for perception of the actual 3D behavior of Mars's atmosphere. A very important feature of the visualization system is the possibility to connect distributed workspaces together. This enables discussions between distributed working groups. The workspace can scale from virtual reality systems to expert desktop applications to web-based project portals. If multiple virtual environments are connected, the 3D position of each individual user is captured and used to depict the scientist as an avatar in the virtual world. The appearance of the avatar can also scale from simple annotations to complex avatars using tele-presence technology to reconstruct the users in 3D. Any change of the feature set (annotations, cutplanes, volume rendering, etc.) within the VR is immediately exchanged between all connected users. This allows that everybody is always aware of what is visible and discussed. The discussion is supported by audio and interaction is controlled by a moderator managing turn-taking presentations. A use case execution proved a success and showed the potential of this immersive approach.

  • 12.
    Gustafsson, Torsten
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Engelke, Wito
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Englund, Rickard
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Hotz, Ingrid
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Concepts of Hybrid Data Rendering2017Inngår i: Proceedings of SIGRAD 2017, August 17-18, 2017 Norrköping, Sweden / [ed] Ingrid Hotz and Martin Falk, Linköping: Linköping University Electronic Press, 2017, Vol. 143, s. 32-39Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We present a concept for interactive rendering of multiple data sets of varying type, including geometry and volumetric data, in one scene with correct transparency. Typical visualization applications involve multiple data fields from various sources. A thorough understanding of such data often requires combined rendering of theses fields. The choice of the visualization concepts, and thus the rendering techniques, depends on the context and type of the individual fields. Efficiently combining different techniques in one scene, however, is not always a straightforward task. We tackle this problem by using an A-buffer based approach to gather color and transparency information from different sources, combine them and generate the final output image. Thereby we put special emphasis on efficiency and low memory consumption to allow a smooth exploration of the data. Therefore, we compare different A-buffer implementations with respect to memory consumption and memory access pattern. Additionally we introduce an early-fragment-discarding heuristic using inter-frame information to speed up the rendering..

    Fulltekst (pdf)
    Concepts of Hybrid Data Rendering
  • 13.
    Kuhn, Alexander
    et al.
    Zuse-Institute Berlin (ZIB), Berlin, Germany.
    Engelke, Wito
    Deutsches Zentrum für Luft- und Raumfahrt (DLR), Braunschweig, Germany.
    Flatken, Markus
    Deutsches Zentrum für Luft- und Raumfahrt (DLR), Braunschweig, Germany.
    Hans-Christian, Hege
    Zuse-Institute Berlin (ZIB), Berlin, Germany.
    Hotz, Ingrid
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Topology-Based Analysis for Multimodal Atmospheric Data of Volcano Eruptions2015Inngår i: Topological Methods in Data Analysis and Visualization IV: Theory, Algorithms, and Applications / [ed] Hamish Carr, Christoph Garth and Tino Weinkauf, Springer, 2015, s. 35-50Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Many scientific applications deal with data from a multitude of different sources, e.g., measurements, imaging and simulations. Each source provides an additional perspective on the phenomenon of interest, but also comes with specific limitations, e.g. regarding accuracy, spatial and temporal availability. Effectively combining and analyzing such multimodal and partially incomplete data of limited accuracy in an integrated way is challenging. In this work, we outline an approach for an integrated analysis and visualization of the atmospheric impact of volcano eruptions. The data sets comprise observation and imaging data from satellites as well as results from numerical particle simulations. To analyze the clouds from the volcano eruption in the spatiotemporal domain we apply topological methods. We show that topology-related extremal structures of the data support clustering and comparison. We further discuss the robustness of those methods with respect to different properties of the data and different parameter setups. Finally we outline open challenges for the effective integrated visualization using topological methods.

  • 14.
    Kuhn, Alexander
    et al.
    Zuse‐Institut Berlin, Germany.
    Engelke, Wito
    Geometric Modeling and Scientific Visualization Center, King Abdullah University of Science and Technology, KSA, Saudi Arabia.
    Rössel, Christian
    Institute for Simulation and Graphics, University of Mageburg, Germany.
    Hadwiger, Markus
    Geometric Modeling and Scientific Visualization CenterKing Abdullah University of Science and Technology, KSA, Saudi Arabia.
    Theisel, Holger
    Institute for Simulation and Graphics, University of Mageburg, Germany.
    Time Line Cell Tracking for the Approximation of Lagrangian Coherent Structures with Subgrid Accuracy2013Inngår i: Computer Graphics Forum, John Wiley & Sons, 2013, Vol. 33, s. 222-234Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Lagrangian coherent structures (LCSs) have become a widespread and powerful method to describe dynamic motion patterns in time‐dependent flow fields. The standard way to extract LCS is to compute height ridges in the finite‐time Lyapunov exponent field. In this work, we present an alternative method to approximate Lagrangian features for 2D unsteady flow fields that achieve subgrid accuracy without additional particle sampling. We obtain this by a geometric reconstruction of the flow map using additional material constraints for the available samples. In comparison to the standard method, this allows for a more accurate global approximation of LCS on sparse grids and for long integration intervals. The proposed algorithm works directly on a set of given particle trajectories and without additional flow map derivatives. We demonstrate its application for a set of computational fluid dynamic examples, as well as trajectories acquired by Lagrangian methods, and discuss its benefits and limitations.

  • 15.
    Lukasczyk, Jonas
    et al.
    Technische Universität Kaiserslautern, Kaiserslautern, Germany.
    Beran, Jakob
    Stockholm University, Stockholm, Sweden.
    Engelke, Wito
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Falk, Martin
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Friederici, Anke
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Garth, Christoph
    Technische Universität Kaiserslautern, Kaiserslautern, Germany.
    Hofmann, Lutz
    Heidelberg University, Heidelberg, Germany.
    Hotz, Ingrid
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Hristov, Petar
    University of Leeds, Leeds, UK.
    Köpp, Wiebke
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Masood, Talha Bin
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Olejniczak, Małgorzata
    University of Warsaw, Warsaw, Poland.
    Rosen, Paul
    University of South Florida, Tampa, USA.
    Sohns, Jan-Tobias
    Technische Universität Kaiserslautern, Kaiserslautern, Germany.
    Weinkauf, Tino
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Werner, Kilian
    Technische Universität Kaiserslautern, Kaiserslautern, Germany.
    Tierny, Julien
    CNRS, Sorbonne Universite, Paris, France.
    Report of the TopoInVis TTK Hackathon: Experiences, Lessons Learned, and Perspectives2021Inngår i: Topological Methods in Data Analysis and Visualization VI: Theory, Applications, and Software / [ed] Ingrid Hotz, Talha Bin Masood, Filip Sadlo and Julien Tierny, Springer, 2021, s. 359-373Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    This paper documents the organization, the execution, and the results of the Topology ToolKit (TTK) hackathon that took place at the TopoInVis 2019 conference. The primary goal of the hackathon was to promote TTK in our research community as a unified software development platform for topology-based data analysis algorithms. To this end, participants were first introduced to the structure and capabilities of TTK, and then worked on their own TTK-related projects while being mentored by senior TTK developers. Notable outcomes of the hackathon were first steps towards Python and Docker packages, further integration of TTK in Inviwo, the extension of TTK with new algorithms, and the discovery of current limitations of TTK as well as future development directions.

    Fulltekst (pdf)
    fulltext
  • 16.
    Lukasczyk, Jonas
    et al.
    Arizona State Univ, AZ 85287 USA.
    Garth, Christoph
    TU Kaiserslautern, Germany.
    Larsen, Matthew
    Lawrence Livermore Natl Lab, CA 94550 USA.
    Engelke, Wito
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Hotz, Ingrid
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Rogers, David
    Los Alamos Natl Lab, NM USA.
    Ahrens, James
    Los Alamos Natl Lab, NM USA.
    Maciejewski, Ross
    Arizona State Univ, AZ 85287 USA.
    Cinema Darkroom: A Deferred Rendering Framework for Large-Scale Datasets2020Inngår i: 2020 IEEE 10TH SYMPOSIUM ON LARGE DATA ANALYSIS AND VISUALIZATION (LDAV), IEEE , 2020, s. 37-41Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents a framework that fully leverages the advantages of a deferred rendering approach for the interactive visualization of large-scale datasets. Geometry buffers (G-Buffers) are generated and stored in situ, and shading is performed post hoc in an interactive image-based rendering front end. This decoupled framework has two major advantages. First, the G-Buffers only need to be computed and stored once-which corresponds to the most expensive part of the rendering pipeline. Second, the stored G-Buffers can later be consumed in an image-based rendering front end that enables users to interactively adjust various visualization parameters-such as the applied color map or the strength of ambient occlusion-where suitable choices are often not known a priori. This paper demonstrates the use of Cinema Darkroom on several real-world datasets, highlighting CDs ability to effectively decouple the complexity and size of the dataset from its visualization.

  • 17.
    Meuschke, Monique
    et al.
    Dept. of Computer Graphics and Simulation, OvG-University Magdeburg, Germany, and Research Campus STIMULATE, Magdeburg, Deutschland.
    Engelke, Wito
    German Aerospace Center, Simulation and Software Technology, Braunschweig, Deutschland.
    Beuing, Oliver
    Institute of Neuroradiology, University Hospital of Magdeburg, Germany, and Research Campus STIMULATE, Magdeburg, Deutschland.
    Preim, Bernhard
    Dept. of Computer Graphics and Simulation, OvG-University Magdeburg, Germany, and Research Campus STIMULATE, Magdeburg, Deutschland.
    Lawonn, Kai
    Institute of Computational Visualistics, University of Koblenz – Landau, Koblenz, Deutschland.
    Automatic Viewpoint Selection for Exploration of Time-dependent Cerebral Aneurysm Data2017Inngår i: Bildverarbeitung für die Medizin 2017: Algorithmen - Systeme - Anwendungen. Proceedings des Workshops vom 12. bis 14. März 2017 in Heidelberg / [ed] Klaus Hermann Maier-Hein, Thomas M. Deserno, Heinz Handels, Thomas Tolxdorff Herausgeber, Springer Berlin/Heidelberg, 2017, s. 352-357Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents an automatic selection of viewpoints, forming a camera path, to support the exploration of cerebral aneurysms. Aneurysms bear the risk of rupture with fatal consequences for the patient. For the rupture risk evaluation, a combined investigation of morphological and hemodynamic data is necessary. However, the extensive nature of the time-dependent data complicates the analysis. During exploration, domain experts have to manually determine appropriate views, which can be a tedious and time-consuming process. Our method determines optimal viewpoints automatically based on input data such as wall thickness or pressure. The viewpoint selection is modeled as an optimization problem. Our technique is applied to five data sets and we evaluate the results with two domain experts by conducting informal interviews.

  • 18.
    Nilsson, Emma
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Lukasczyk, Jonas
    TU Kaiserslautern, Germany.
    Engelke, Wito
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Masood, Talha Bin
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Svensson, Gunilla
    Stockholm Univ, Sweden.
    Caballero, Rodrigo
    Stockholm Univ, Sweden.
    Garth, Christoph
    TU Kaiserslautern, Germany.
    Hotz, Ingrid
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Exploring Cyclone Evolution with Hierarchical Features2022Inngår i: 2022 IEEE WORKSHOP ON TOPOLOGICAL DATA ANALYSIS AND VISUALIZATION (TOPOINVIS 2022), IEEE , 2022, s. 92-102Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The problem of tracking and visualizing cyclones is still an active area of climate research, since the nature of cyclones varies depending on geospatial location and temporal season, resulting in no clear mathematical definition. Thus, many cyclone tracking methods are tailored to specific datasets and therefore do not support general cyclone extraction across the globe. To address this challenge, we present a conceptual application for exploring cyclone evolution by organizing the extracted cyclone tracks into hierarchical groups. Our approach is based on extrema tracking, and the resulting tracks can be defined in a multi-scale structure by grouping the points based on a novel feature descriptor defined on the merge tree, so-called crown features. Consequently, multiple parameter settings can be visualized and explored in a level-of-detail approach, supporting experts to quickly gain insights on cyclonic formation and evolution. We describe a general cyclone exploration pipeline that consists of four modular building blocks: (1) an extrema tracking method, (2) multiple definitions of cyclones as groups of extrema, including crown features, (3) the correlation of cyclones based on the underlying tracking information, and (4) a hierarchical visualization of the resulting feature tracks and their spatial embedding, allowing exploration on a global and local scale. In order to be as flexible as possible, our pipeline allows for exchanging every module with different techniques, such as other tracking methods and cyclone definitions.

  • 19.
    Otto, Mathias
    et al.
    University of Magdeburg, Germany.
    Kuhn, Alexander
    University of Magdeburg, Germany.
    Engelke, Wito
    University of Magdeburg, Germany.
    Theisel, Holger
    University of Magdeburg, Germany.
    2011 IEEE Visualization Contest Winner: Visualizing Unsteady Vortical Behavior of a Centrifugal Pump2012Inngår i: IEEE Computer Graphics and Applications, ISSN 0272-1716, E-ISSN 1558-1756, Vol. 32, nr 5, s. 12-19Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In the 2011 IEEE Visualization Contest, the dataset represented a high-resolution simulation of a centrifugal pump operating below optimal speed. The goal was to find suitable visualization techniques to identify regions of rotating stall that impede the pump's effectiveness. The winning entry split analysis of the pump into three parts based on the pump's functional behavior. It then applied local and integration-based methods to communicate the unsteady flow behavior in different regions of the dataset. This research formed the basis for a comparison of common vortex extractors and more recent methods. In particular, integration-based methods (separation measures, accumulated scalar fields, particle path lines, and advection textures) are well suited to capture the complex time-dependent flow behavior. This video (http://youtu.be/oD7QuabY0oU) shows simulations of unsteady flow in a centrifugal pump.

  • 20.
    Otto, Mathias
    et al.
    Institute for Simulation and Graphics, University of Magdeburg, Magdeburg, Germany.
    Kuhn, Alexander
    Institute for Simulation and Graphics, University of Magdeburg, Magdeburg, Germany.
    Engelke, Wito
    King Abdullah University of Science and Technology (KAUST), Saudi Arabia.
    Theisel, Holger
    Institute for Simulation and Graphics, University of Magdeburg, Magdeburg, Germany.
    Visualizing Dynamic Flow Transport of a Centrifugal Pump2012Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this work we present our results for applying specially designed time-dependent flow visualization methods to a simulation of a centrifugal pump. The simulation has been performed on a high-resolution grid (Figure 1) for 80 time steps using three turbulence methods (SAS, DES, SST [1]) with special focus on the analysis of the so called rotational stall phenomenon. This causes large areas of recirculation and significantly affects the efficiency and life time of the device. We provide a comparative visual analysis using common local vortex detectors as λ2 and the Q criterion, and recent local methods as Sujudi & Haimes [2], and cores of swirling particle motion [3]. Local methods are shown to be insufficient to represent the functional impact and structural importance of the relevant features over time. To efficiently visualize stall cells we applied a set of global and time-dependent measures to convey size, spatial structure and temporal evolution of important transport effects and large-scale turbulent flow structures. Our analysis provides qualitative statements about the application of Lagrangian methods as FTLE [4], integral pressure, arc length of path lines and texture advection (Figure 1) revealing recirculation zones and blocked channels

  • 21.
    Otto, Mathias
    et al.
    Otto-von-Guericke-Universität, Magdeburg, Deutschland.
    Kuhn, Alexander
    Otto-von-Guericke-Universität, Magdeburg, Deutschland.
    Engelke, Wito
    Otto-von-Guericke-Universität, Magdeburg, Deutschland;King Abdullah University of Science and Technology, Saudi Arabien.
    Theisel, Holger
    Otto-von-Guericke-Universität, Magdeburg, Deutschland.
    Visuelle Analysemethoden für das Durchströmungsverhalten einer zentrifugalen Pumpe2012Konferansepaper (Annet vitenskapelig)
    Abstract [de]

    Diese Arbeit beschreibt eine visuelle Funktionsanalyse einer zentrifugalen Pumpe (Abb. 1) [1], für welche sowohl etablierte als auch neu entwickelte Visualisierungstechniken eingesetzt werden. Eine solche Pumpe besteht aus einem Einströmbereich, einem Transportbereich, in dem ein Impeller das Fluid beschleunigt und in den Auslass drückt. Von der Pumpe sind drei simulierte Datensätze mit unterschiedlichen Turbolenzmodellen namens Scale-Adaptive Simulation (SAS), Detached Eddy Simulation (DES) und Shear Stress Transport (SST) gegeben. Jeder Datensatz beinhalte 80 Zeitschritte, die einer Umdrehung des Impellers entsprechen. Das zugrunde liegende Gitter besteht aus ca. 6.5 millionen hexahedralen Zellen und 6.7 millionen Datenpunkten.Wichtig für die Funktionsanalyse sind Wirbelablösungen an den Impellerblättern, die zu großen, stabilen Wirbeln führen können, sodass komplette Kanäle des Impellers blockiert werden, einen sogenannten Rotating Stall. Dieses Phänomen beeinträchtigt die Effizienz und die Lebensdauer der Pumpe.

1 - 21 of 21
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