Visualization of Volcanic Eruption Simulations (CFDLib)
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Transcript of Visualization of Volcanic Eruption Simulations (CFDLib)
Visualization of Volcanic Eruption Simulations (CFDLib)
Visualization of Volcanic Eruption Simulations (CFDLib)XSEDE ECSS Symposium, Mar 2013
Amit Chourasia (feat. Dong Ju Choi)
Visualization Services
San Diego Supercomputer Center, UCSD
Project Team
PI: Darcy Ogden, SIO, UCSD
Code: CFDLib (LANL)
ECSS Team•Computation: Dong Ju Choi, Mahidhar Tateneni•Visualization: Amit Chourasia
Project Goals
•Optimize CFDlib•Perform large scale runs on Gordon @
SDSC•Visualize data (existing and new)
CFDLib (feat. Dong Ju Choi)
Collection of hydro codes compressible flowincompressible flow multiphase flowMagneto hydrodynamic forces and multi-fluid solutions
•Modular: enables fast code development•Serial only option to simulate the motion of a Lagrangian projectile (Rock deformation), passing through an Eulerian gas (Fume).
• Simulate explosive volcanic jets using CFDLib from LANL
• Consider both rock deformation (in Lagrangian ) and gas explosion (in Eulerian)
SIMULATION
Computation• Port the code on SDSC’s Gordon
• Performance test to find a bottle neck and perform optimization
• Large scale run on vSMP node (100 times more resolution)
• Output found not correct. PI decided to abort the project because it debugging would not be easy▫ A new Java based implementation of the CFDLib is
upcoming, the PI is transitioning to new code.▫ ECSS computation support is discontinued, but
visualization work proceeded
Data
•ASCII Tecplot files (300 MB per file) •~15 variables (air, ash, steam, rock …)•Rectilinear adaptive grid (610x600x2000
cells)•300 – 400 time steps per simulation•Simulation ensemble comprising of nine
runs (varying input conditions of rock viscosity & pressure)
Viz Work Plan
•Study existing data •Study visualizations done by PI in Tecplot•Identify suitable visualization tools•Transform data•Create visualization for communication –
ash, rock, steam, distribution•Identify features of interest for scientific
enquiry – crater growth, mass flux distribution, etc …
– crater area, etc ..
Viz Snapshots provided by PI
Challenges
•Identify viz tool•Data translation. VisIt unable to read
existing files•How to display multiple volumetric
variables simultaneously? •Develop adequate transfer functions for
each variable?
Viz Exploration
Study and show volumetric distribution of
air, ash, rock & steam
How to view all these together?
Exploit Symmetry
Presented at Vis Showcase XSEDE 12
Mass Flux slice at 100m200m300m400m500m depths
Each column shows
different sim with low
viscosity rock at varying
pressure as input
Rock slice at 100m200m300m400m500m depths
Each column shows
different sim with low
viscosity rock at varying
pressure as input
Ash slice at 100m200m300m400m500m depths
Each column shows
different sim with low
viscosity rock at varying
pressure as inputMovie
MovieEach row shows different simulation
Visualization Process Employed•Remote interactive visualization on
Gordon and Trestles•Face to face and VNC sessions with
the PI during interactive exploration of data
•Batch visualization over time series•Create and share movies•Iterative process (rinse and repeat)
Conclusions/Lessons• Created several visualizations for investigation of new insights as
well as communication of results▫ ~26 movies, ~100,000 images▫ ~30,000/50,000 SUs consumed in viz
• Output data could be written out in parallel friendly format instead of ASCII Tecplot files.
• Project plans evolve over time, sometimes revamped significantly. PIs priorities also change during the project.
• Engaging the PI with hands on tutorial was very useful and productive▫ Documented and handed over the scripts, parameters and state files to the
PI▫ PI can recreate and reuse settings for other similar data
• Remote interactive visualization applications are now quite mature. End users can be trained to carry out basic tasks easily using VisIt.
• Unsolicited quote from PI “These snapshot visualizations have been very useful for identifying key dynamics important to studying eruption physics.”
Publications• D.E. Ogden and K.H. Wohletz. “3D Numerical Models of
Co-Eruptive Volcanic Vent Evolution and Influence on Eruptive Dynamics”. American Geophysical Union, Fall Meeting 2011, abstract #V33A-2607
• A. Chourasia, D. Ogden and K. Wohletz. “Snapshot of a Volcano Eruption Simulation”. XSEDE 12 Conference. Chicago
• Another manuscript under preparation by PI
Acknowledgement:Brad Whitlock (LLNL) for rapid bug fixes and suggestions for
VisIt application.