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03/13/2008 07:00:00

One of Five Centers of Excellence for Predictive Science

PASADENA, Calif.--With a $17 million grant from the National Nuclear Security Administration (NNSA), the California Institute of Technology becomes one of five new centers of excellence that will focus on the emerging field of predictive science.

Michael Ortiz, the Dotty and Dick Hayman Professor of Aeronautics, professor of mechanical engineering, and director of Caltech's new Predictive Science Academic Alliance Program (PSAAP) Center, says Caltech will focus its efforts on the high-energy density dynamic response of materials, with demonstrations of hypervelocity impact response.

Hypervelocity impact is central to a number of scientific and application areas, including the design of protective shields for space structures and the understanding of meteorite impact cratering, Ortiz says. Accurate computer simulation is critical to the understanding of experiments that involve velocities reaching 10 kilometers per second, pressures in the megabar range, and extraordinarily high temperatures and deformation rates.

"The range of complex physics that is set in motion during hypervelocity impact is staggering," Ortiz remarks. "It includes melting, vaporization, and plasmas; hydrodynamic instabilities, mixed-phase flows, and mixing; and fracture, fragmentation, spall, and ejecta.

"The modeling and simulation of each of these phenomena in isolation is a scientific challenge in itself, but the predictive simulation of their coupled integral behavior is truly at the grand-challenge level and provides an exceedingly exacting test of predictive science."

Predictive science is the application of verified and validated computational simulations to predict the behavior of complex systems where routine experiments are not feasible. The research effort, which involves Caltech and four other selected PSAAP centers, will focus on unclassified applications of interest to NNSA and its three national laboratories: Lawrence Livermore National Laboratory, Los Alamos National Laboratory, and Sandia National Laboratories.

"At the core of this game-changing 'predictive science' paradigm shift is the ability to quantify uncertainties in the performance of complex systems by means of concerted and highly integrated experimental, computational, and analytical programs," Ortiz remarks.

The PSAAP centers, named by NNSA on March 7, will develop models and software for their large-scale simulations, as well as methods associated with the emerging disciplines of verification and validation and uncertainty quantification. The centers will be administered by the office of Advanced Simulation and Computing (ASC), which has funded the ASC Center at Caltech for the past 10 years.

"Caltech is in a unique position to advance the field of predictive science because of its culture of close interdisciplinary work among its faculty and research groups, exemplified by the highly successful ASC center led by Dan Meiron, and because of its longstanding tradition of approaching modeling and simulation at its most fundamental level," Ortiz says.

Experiments will be performed at experimental facilities in Caltech's Graduate Aeronautical Laboratories (GALCIT), including the newly-constructed Small Particle Hypervelocity Impact Range (SPHIR), notes Ares Rosakis, the von Kármán Professor of Aeronautics, professor of mechanical engineering, and director of GALCIT.

The executive director of Caltech's PSAAP Center is Mark Stalzer, executive director of Caltech's Center for Advanced Computing Research (CACR). The PSAAP Center will coordinate activities in areas including computational fluid dynamics, led by Dan Meiron, the Jones Professor of Applied and Computational Mathematics and Computer Science; computational science and engineering, led by CACR's principal computational scientist, Michael Aivazis; experimental science, led by Rosakis; solid dynamics and materials, led by Ortiz; and uncertainty quantification, led by Houman Owhadi, assistant professor of applied and computational mathematics and control and dynamical systems.

For further details on PSAAP, visit http://www.sandia.gov/NNSA/ASC/univ/psaap.html. 

Written by elisabeth nadin