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Dan R. Lipşa 1 , Robert S. Laramee 1 , Simon J. Cox 2 , and I. Tudur Davies 2. 2 Institute of Mathematics and Physics Aberystwyth University Aberystwyth, Wales, UK. 1 The Visual and Interactive Computing Group Computer Science Dept. Swansea University Swansea, Wales, UK. - PowerPoint PPT Presentation
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VisWeek 2011 - Providence, RI, USA 1
FoamVis: Visualization of 2D Foam Simulation Data
Dan R. Lipşa1, Robert S. Laramee1, Simon J. Cox2,and I. Tudur Davies2
1The Visual and InteractiveComputing Group
Computer Science Dept.Swansea University
Swansea, Wales, UK
2Institute of Mathematics and Physics
Aberystwyth UniversityAberystwyth, Wales, UK
27 October 2011
Dan R. Lipsa – Swansea [email protected]
FoamVis: Visualization of 2D Foam Simulation Data
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Overview
Motivation and Introduction to Foam Research
FoamVis Features Results Summary and
Conclusions Visualization of bubble paths color-mapped to elongation.
Dan R. Lipsa – Swansea [email protected]
FoamVis: Visualization of 2D Foam Simulation Data
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Motivation: Why Study Foam?
Displaces oil from porous media Mineral flotation and separation
Dan R. Lipsa – Swansea [email protected]
FoamVis: Visualization of 2D Foam Simulation Data
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Foam
Two-phase material: liquid and gas Complex behavior:
Elastic solid at low stress Plastic solid as stress increases Liquid at high stress
Dan R. Lipsa – Swansea [email protected]
FoamVis: Visualization of 2D Foam Simulation Data
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Foam Research Main Challenge
Foam behavior - Herschel Bulkley:
Plastic solid
Liquid
Foam properties:- bubble size- bubble distribution- liquid fraction- surface tension?
Possible solution:Simulate foam at bubble scale (Surface Evolver)
Dan R. Lipsa – Swansea [email protected]
FoamVis: Visualization of 2D Foam Simulation Data
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Foam Simulations Constriction
704 bubbles 1000 time steps
Sedimenting discs 1500 bubbles 252 time steps
Dan R. Lipsa – Swansea [email protected]
FoamVis: Visualization of 2D Foam Simulation Data
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Topological Change Bubbles in a 2D foam at
equilibrium are 3-way connected at 120º angles.
As foam is sheared, the topology of the soap film changes.
Topological changeBubbles color-mapped by velocity magnitude.
Constriction simulation.
Dan R. Lipsa – Swansea [email protected]
FoamVis: Visualization of 2D Foam Simulation Data
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Motivation: Bubble Scale Simulation Research Challenges
Triggers to various foam behaviors are difficult to infer. Multiple attributes
Difficult to visualize general foam behavior. Time-dependent Large fluctuations in attribute values caused by
changes in the topology of the film network.
Dan R. Lipsa – Swansea [email protected]
FoamVis: Visualization of 2D Foam Simulation Data
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Motivation: Standard Methods for Foam Visualization Drawbacks
Require intervention in the simulation code for summarizing and saving the relevant data.
No ability to explore and analyze data through navigation, selection and encoding.
Slow, coarse level of detail.
Constriction simulation, Average velocity over all time steps
Dan R. Lipsa – Swansea [email protected]
FoamVis: Visualization of 2D Foam Simulation Data
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FoamVis Features Works with any Surface Evolver (SE) simulation: parse
and process directly SE files Color mapping of bubble attributes: velocity, pressure,
area, deformation Overlays
Topological changes Forces
Constriction simulation, Average velocity over all time steps
Dan R. Lipsa – Swansea [email protected]
FoamVis: Visualization of 2D Foam Simulation Data
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FoamVis Features Bubble selection/filtering: by bubble ID, location, and
attribute value (using a histogram) Image based statistical computation (average, count)
For all time steps or for a time window behind the current time step.
Around a moving body Bubble paths Multiple linked views Focus&Context
Bubble and viewWhere do most bubbles with negative velocity along X occur? Count + Topological changes overlay.
Dan R. Lipsa – Swansea [email protected]
FoamVis: Visualization of 2D Foam Simulation Data
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Results: Pattern of Bubble Centers Traversing Loops
Sedimenting discs simulation. Pattern of bubbles traversing loops. Orange: descent, Purple: ascent
Dan R. Lipsa – Swansea [email protected]
FoamVis: Visualization of 2D Foam Simulation Data
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Results: Why Do Bubbles Traverse Loops?
Why do bubbles traverse loops?
Dan R. Lipsa – Swansea [email protected]
FoamVis: Visualization of 2D Foam Simulation Data
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Results: Why does one disc descend quicker than the other?
Sedimenting discs simulation (t=0).Elongation: blue-red palette, Pressure: blue-tan palette.Network force: black, Pressure force: yellow Resultant force: green.
The network force - contacting soap films pull normal to the circumference with the force of surface tension.The pressure force - adjacent bubbles push against the disc with their pressure force.
Dan R. Lipsa – Swansea [email protected]
FoamVis: Visualization of 2D Foam Simulation Data
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Sedimenting-discs simulation (t=43). Elongation - blue-red palette, Pressure - blue-tan palette. Sliding time window average over 10 iterations. Network force: black, Pressure force: yellow Resultant force: green.
Results: Why do discs drift laterally as they sediment?
Dan R. Lipsa – Swansea [email protected]
FoamVis: Visualization of 2D Foam Simulation Data
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Summary and Conclusions Foam research application area. FoamVis - exploration, visualization and analysis of
foam simulation data. Validate hypothesis, make new discoveries and gain
insight into foam behavior.
Dan R. Lipsa – Swansea [email protected]
FoamVis: Visualization of 2D Foam Simulation Data
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Acknowledgments We thank Ken Brakke, Susquehanna University, PA, for
answering our many questions about the Surface Evolver. This research was supported in part by:
EPSRC/P&G grant EP/F000049/1, EPSRC grant EP/D071127/1 Research Institute of Visual Computing (rivic.org) Wales
Thank you for your attention! Any questions?
Dan R. Lipsa – Swansea [email protected]
FoamVis: Visualization of 2D Foam Simulation Data
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Why 2D foam simulations?
Shorter simulation time. Available 2D experimental data. Experimental data easier to segment.
Image by E. Janiaud
Dan R. Lipsa – Swansea [email protected]
FoamVis: Visualization of 2D Foam Simulation Data
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Surface Evolver Foam simulation program - Ken Brakke, Mathematics
Department, Susquehanna University, PA Study of surfaces shaped by surface tension and other
energies, and subject to various constraints
Input Output
Soap film with fixed (square wire frame) and free boundaries (surface of the table)