A publication of the Office of Advanced Simulation & Computing, NA-121.2, NNSA Defense Programs
March 2008
NA-ASC-500-08—Issue 6
Printable Version(~1MB PDF)
Springtime in Washington
Editorial by Bob Meisner
Ret. General Smolen has introduced some organizational changes in Defense Programs at NNSA HQ. A major change that affects the ASC Program is that Dimitri Kusnezov has been asked to lead NA-11, I have assumed the role of acting ASC Division leader, and Njema Frazier is the acting deputy ASC Division Leader.
Our budget continues to be a challenge. The Future-Years Nuclear Security Program (FYNSP) budget continues to drop until 2011 when it finally begins to see some small increases.
Five Research Institutions Selected to Become Part of ASC’s New Academic Alliance Program
On March 7, 2008, the National Nuclear Security Administration (NNSA) announced the selection of its five new centers of excellence whose primary focus will be on the emerging field of predictive science. Five universities will receive $17 million each over a five-year period under NNSA’s Predictive Science Academic Alliance Program (PSAAP) agreement:
- The Center for the Predictive Modeling and Simulation of High-Energy Density Dynamic Response of Materials at California Institute of Technology.
- The Center for Prediction of Reliability, Integrity and Survivability of Microsystems (PRISM) at Purdue University.
- The Center for Predictive Simulations of Multi-Physics Flow Phenomena with Application to Integrated Hypersonic Systems at Stanford University.
- The Center for Radiative Shock Hydrodynamics (CRASH) at University of Michigan.
- The Center for Predictive Engineering and Computational Sciences (PECOS) at University of Texas, Austin.
ASC Principal Investigators’ Meeting Puts it all Together in Monterey, CA
The 2008 ASC Principal Investigators’ Meeting was held February 25-27 in Monterey, California. The theme of this year’s meeting was “Putting It All Together,” highlighting the many ways that the ASC Program is accomplishing its core mission and broadening its role for the future. Featured were three “end-to-end” sessions—one from each NNSA laboratory—that told a story of how a mission-critical grand challenge is being met using the various program elements and “putting them all together.” This theme was apparent through the many other programmatic, technical, and strategic presentations given by NNSA headquarters and laboratory staff during the two-day meeting.
QASPR’s Successful “Blind” Best Estimate Plus Uncertainty Predictions vs. Experimental Data for Radiation Effects Study
The Sandia Qualification Alternative to the Sandia Pulsed Reactor (QASPR) project team has successfully made blind predictions, with associated uncertainty quantification, of short-pulse neutron effects test data that were taken at the Sandia Pulsed Reactor (SPR) before shutdown of that facility in FY06.
New Development Tool Enables Automatic Data Collection
The ALE3D Code Team has completed a migration of its software development processes to the SourceForge Enterprise Edition (SFEE) collaborative development tool. SFEE, a commercial tool from CollabNet, is installed locally on Lawrence Livermore's yellow-net and is a secure, centralized, enterprise solution for optimizing and managing distributed software development.
Encore Error Estimation Toolkit with Method of Manufactured Solutions
Encore is a component of SIERRA Mechanics that provides quantitative error estimates for simulation results or adaptive grid refinement. This information can be used to quantify or reduce the solution error. The Encore software toolkit has been extended to enable the Method of Manufactured Solutions (MMS). Using the Encore/MMS capability, developers and users of engineering and physics simulation software can perform code verification that is mathematically rigorous.
New Scalable Solver for SIERRA Mechanics
Linear solvers are the central building block of many applications. These solvers must be robust, accurate, scalable, and fast. The complexity arising from the growing number of constraint equations is of particular concern in this regard. These constraints make model building easier, but have been extremely challenging to iterative solvers.
MOU Signed on High Performance Computing Collaboration
A Memorandum of Understanding was signed on March 7, 2008, by Sandia National Laboratories (Sandia) and Los Alamos National Laboratory (LANL) to formalize the New Mexico Alliance for Computing at the Extreme Scale (ACES), which will provide High Performance Computing (HPC) capability computing for NNSA’s stockpile stewardship mission. The ACES will create the strongest possible HPC team in the US to meet NNSA’s most challenging computing needs and also support the decision to reduce capability computing sites across the NNSA Complex. Independently, LANL and Sandia have been world leaders in HPC for several decades. By bringing these two organizations together in the ACES partnership, stronger, more tightly integrated technical teams will emerge, efficiencies will be realized, and facilities at the two institutions will be optimized. The partnership is built on the strengths of both national laboratories. Joint teams have been formed to design, architect, deploy, and operate future NNSA production capability platforms. These platforms will support weapons physics and engineering calculations that require running across an entire platform.
W78 Drop Impact Sensitivity Analysis with SIERRA Mechanics Software
In a project jointly funded by the Sandia’s ASC Verification and Validation Program and by Sandia’s weapons engineering program, a full-system finite element structural model of the W78 has been built and is being employed to simulate accidental drop impact events. This study is an important component of the safety technical basis assessment for the W78 and will identify possible damage mechanisms that could lead to the loss of assured safety of the weapon. These simulations employ Sandia’s SIERRA Mechanics software to capture the complex internal component and subsystem deformations that occur during the impact event. These simulations were enabled by new and robust material contact algorithms developed for SIERRA.
To date, 50 different drop impacts have been simulated to assess the sensitivity of the warhead’s structural response to variations in impact velocity and angle. This sensitivity analysis will identify the worst-case set of impact conditions. Subsequent uncertainty quantification (UQ) studies will be performed using Sandia’s DAKOTA optimization/UQ software, coupled with SIERRA, to assess the effect of material property uncertainties on the structural response of the W78. This structural response information will be used by the W78 system designers to quantify margins and uncertainties for the safety-critical components in the W78.
Red Storm Supports High-Priority Simulations for National Security Needs
During 12 weeks beginning December 8, 2007, Red Storm was configured as completely classified, applying the entire resource to support two high-priority calculations involving separate Sandia missions. The initial work was interrupted to make room for a time-urgent set of calculations, which were accomplished on time and consumed over 6 million node hours. The original project reclaimed the system and continued processing to completion, utilizing over 12 million node hours executing jobs using 12,900 dual processor nodes. Both of these programs were classified, and information is being tightly controlled; but the service provided by the Red Storm system and visualization and data management clusters, as well as the support provided by operations teams, were essential in the successful execution of these nationally important runs.
Newly Designed Web Site for the Los Alamos ASC Program
Los Alamos has published a newly designed ASC Web site available to the public at http://www.lanl.gov/asc. It features short articles about relevant research in a section called “A New Way to Understand.” There are several links to information about the Roadrunner project, including its public Web site and a Roadrunner Fact Sheet.
ASC Salutes
Lin Yin is one of the more prolific and successful users of the VPIC kinetic plasma modeling code. A technical staff member in Plasma Theory and Applications section of the Applied Science and Methods Development Group of the Applied Physics Division (X-Division) at Los Alamos National Laboratory (LANL), Lin has led the VPIC verification and validation effort. She has done high-impact PIC modeling in several settings, including electron sources in x-ray radiography, laser plasma interaction, laser-ion accelerators, magnetic reconnection, collisionless shocks, and kinetic Alfvén waves. She is the point of contact for laser-plasma interaction kinetic modeling at LANL, where she serves as liaison between the laser-plasma experimental and modeling teams.
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