http://www.phy.ornl.gov/tsi/ - PowerPoint PPT Presentation

1 / 18
About This Presentation
Title:

http://www.phy.ornl.gov/tsi/

Description:

Use PROBE environment for staging data between simulation platforms and ... Develop new data analysis techniques/tools tailored to our application, allowing ... – PowerPoint PPT presentation

Number of Views:37
Avg rating:3.0/5.0
Slides: 19
Provided by: antho112
Learn more at: https://www.anl.gov
Category:
Tags: gov | http | ornl | phy | ray | tsi | www

less

Transcript and Presenter's Notes

Title: http://www.phy.ornl.gov/tsi/


1
TeraScale Supernova Initiative
http//www.phy.ornl.gov/tsi/
2
Investigator Team
  • Cross-Cutting Team
  • Long-Term Collaborations
  • Structured like SciDAC

TOPS
  • Linear System/Eigenvalue Problem Solution
    Algorithms for Radiation Transport and Nuclear
    Structure Computation
  • Dongarra (UT, ORNL)
  • Saied (UIUC, NCSA)
  • Saylor (UIUC, NCSA)
  • Radiation Transport/
  • Radiation Hydrodynamics
  • Blondin (NC State)
  • Bruenn (FAU)
  • Hayes (UCSD)
  • Mezzacappa (ORNL)
  • Swesty (SUNYSB)
  • Supernova Science
  • Blondin
  • Bruenn
  • Fuller
  • Haxton
  • Hayes
  • Lattimer
  • Meyer (Clemson)
  • Mezzacappa
  • Swesty

TOPS
CCA PERC TSTT
  • Nuclear Structure Computations
  • for EOS and Neutrino-Nucleus/
  • Nucleon Interactions
  • Dean (ORNL, UT)
  • Fuller (UCSD)
  • Haxton (INT, Washington)
  • Lattimer (SUNYSB)
  • Prakash (SUNYSB)
  • Strayer (ORNL, UT)

SDM
  • Visualization
  • Baker (NCSA)
  • Toedte (ORNL)

3
  • Goal
  • Ascertain the explosion mechanism(s).
  • Reproduce supernova phenomenology (element
    synthesis neutrino,
  • gravitational wave, and gamma ray signatures
    neutron star kicks
  • gamma ray burst connection)
  • Relevance
  • Dominant source of many elements in the
    Universe.
  • Given sufficiently well developed models, serve
    as laboratories for
  • fundamental nuclear and particle physics
    that cannot be explored
  • in terrestrial laboratories.
  • Driving application in computational science
    (radiation transport,
  • hydrodynamics, nuclear physics, applied
    mathematics, computer
  • science, visualization).
  • Paradigm
  • Result from stellar core collapse and
  • bounce in massive stars.
  • Radiatively driven (perhaps some are
  • MHD driven, or both).

4
Convection
  • Need Boltzmann Solution
  • Need Angular Distribution
  • Need Spectrum
  • Gray Schemes Inadequate
  • Spectrum Imposed
  • Limited Angular Information
  • (Few Moments)
  • Parameterized
  • (No First Principle Solution)
  • The bar is high! (10 effects can
  • make or break explosions.)

5
1D
1D
0D
0D
Neutrino Energy
Lightbulb
FLD
MGFLD
MGBT
D
Space
Burrows, Hayes, and Fryxell
Janka and Mueller
Mezzacappa et al.
1D
Herant et al.
TSI Year 1
TSI Year 2
2D
Swesty
Fryer and Heger
Past Transport in 2D Models D Diffusion FLD
Flux-Limited Diffusion MGFLD Multigroup
FLD MGBT Boltzmann Transport
TSI Year 3
TSI Year 2
3D
Gray Models
6
  • Latest TSI 2D/3D Models
  • Hydrodynamics only.
  • Focused on understanding 2D/3D flow and its
  • coupling to shock wave.
  • Convectively stable.
  • 2D model exhibits bipolar explosion (due to
  • nonlinear flow-shock interaction).
  • 3D model exhibits similar long-wavelength
  • behavior. Key finding.
  • New rolling flows identified.
  • AAS Meeting Ap.J. Submitted

2D Model
3D Model
7
Explosion Mechanism Open Questions
  • What is the Recipe for Explosion?

Neutrino Heating
Convection
General Relativity
Rotation
Magnetic Fields
  • Are there multiple mechanisms?
  • Neutrino-driven supernovae
  • MHD-driven supernovae
  • Supernovae driven by both neutrinos and MHD
    effects
  • One mechanism for a class of stars?
  • Is the mechanism tailored to the individual star?

8
Nuclear and Weak Interaction Physics Needs
High-Density EoS
Nuclear MatterOpacities
Thomas Fermi (Classical)
Classical treatment of many-body problem.
Ensembles
Hartree-Fock
Density of States
Lowest order solution to the quantum mechanical
many-body problem.
e-capture
n-nucleus
Shell Model Monte Carlo
b-decay
Shell Model Diagonalization
Time
Advanced solutions to the many body problem.
Bloch-Horowitz
Solve exact many-body problem.
9
Supernova Nucleosynthesis
R-Process Breakthrough
  • r-process can occur in symmetric environment
    (equal numbers of protons and
  • neutrons) under certain conditions (high
    entropy, fast expansion).
  • Meyer, PRL Submitted

10
Supernova Science
Hydrodynamics Explicit Differencing Reactive
Flows Newtonian General Relativistic
Nuclear, Weak Interaction Physics Thermodynamics (
Composition), Neutrino Sources and Interactions
Radiation Transport Implicit Differencing MGFLD Pr
econditioners Sparse System Solvers MGBT Precondit
ioners Sparse System Solvers (Matrix Free)
11
Integration of Technologies
Generation 3
High-Resolution 3D MGFLD with Full Integration
of Components (Ensemble of Nuclei, State of the
Art Neutrino-Matter Interactions, ...)
Increasing Integration
Generation 2
Inclusion of state of the art neutrino
interactions in Generation 1 MGBT/ MGFLD
Simulations

Generation 1
Increasing Integration
2D MGFLD Simulation with Naive Neutrino
Interactions and Single-Nucleus Equation of
State Computation of State of the Art
Neutrino-Matter Interactions
12
Supernova Simulation Timeline
Year 0
Year 1
Year 2
Year 3
Year 4
Year 5
3D MGFLD Models w/ AMR (4D)
2D MGFLD Models (3D)
3D MGFLD Models (4D)
2D Boltzmann Models (5D)
1D Boltzmann Models (3D)
3D Boltzmann Models (6D)
13
ISIC Collaborations TOPS
  • Nonlinear Algebraic Equations
  • Linearize
  • Solve via Multi-D Newton-Raphson Method
  • Large Sparse Linear Systems

Boltzmann Equation nonlinear integro-PDE
  • Implicit Time Differencing
  • Extremely Short Neutrino-Matter
  • Coupling Time Scales
  • Neutrino-Matter Equilibration
  • Neutrino Transport Time Scales

Memory Requirements (assuming matrix-free
methods) 10s Gb up to 1/2 Tb
Progress Sparse Approximate Inverses for 2D
MGFLD (Saylor, Smolarski, Swesty J. Comp.
Phys.) ADI-Like Preconditioner for Boltzmann
Transport (DAzevedo et al. Precond 2001,
NLAA) AGILE-BOLTZRAN, V2D codes turned over to
TOPS for analysis and development.
14
ISIC Collaborations CCTTSS
  • TSI Code
  • F90 MPI Code
  • Object-Oriented Design for Interoperability and
    Reuse
  • Application Framework
  • IBEAM Interoperability Based Environment for
    Adaptive Meshes
  • NASA HPCC-Funded Project (PI Swesty)
  • AMR PARAMESH

Goal Develop our framework to be
CCA-compliant. Initiated discussions with ANL,
LLNL, and ORNL members of CCTTSS.
15
ISIC Collaborations PERC
  • Assess Code Performance on Parallel Platforms
  • Identify Code Optimizations to Increase
    Performance
  • TSI Code Suite
  • Hydrodynamics
  • VH-1 (PPM)
  • ZEPHYR (Finite Difference)
  • Neutrino Transport
  • AGILE-BOLTZTRAN 1D General Relativistic Adaptive
    Mesh
  • Hydrodynamics with 1D Boltzmann
    Transport
  • V2D 2D MGFLD Transport Code
  • V3D 3D MGFLD Transport Code (Under Development)
  • 2D/3D Boltzmann Code (Under Development)

VH-1 numerical hydrodynamics algorithm scales
well.
Results for VH-1
16
ISIC Collaborations SDM
  • Use PROBE environment for staging data between
    simulation platforms and
  • end-user visualization platforms.
  • Develop new data analysis techniques/tools
    tailored to our application, allowing
  • (a) data reduction and (b) discovery
    potential.
  • Use of agent technology for distributed data
    analysis (data analysis must be
  • done in parallel to achieve reasonable
    throughputs).

17
ISIC Collaborations TSTT
Adaptive Quadratures (Direction Cosines) for
Multidimensional Radiation Transport
  • Greatest challenge to completing 3D Boltzmann
  • simulations is memory.
  • Minimize number of quadratures to minimize
  • memory needs while maintaining physical
  • resolution. (Also important for 1D/2D MGBT.)
  • Optimization Problem

Results for 1D Boltzmann Transport on Milne
Problem (DAzevedo)
Extended Core
Compact Core
18
Collaboration with Supporting Base Projects
Networking
  • Identify Optimal Paths in Our Collaborative
    Visualization Server-Client Model
  • Maximize Bandwidth along these Paths (Not
    Achieved Using Current Protocols)
  • Participated in ORNL Workshop on DoE
    High-Performance Network RD
  • and Applications
  • Convey TSI Needs to Networking Team
  • Participate in White Paper to Define and
    Develop Interface between Efforts
Write a Comment
User Comments (0)
About PowerShow.com