October 7, 2020
Many of the decisions we make are now guided by computational simulations, from designing new spacecraft to predicting the spread of a pandemic. But it's not enough for a simulation model to just issue predictions. A decision-maker needs to know just how much those predictions can be trusted.
This is the objective of research in the critical area of predictive science, which is about to take a major step forward at The University of Texas at Austin. The Oden Institute for Computational Engineering and Sciences has been selected by the Department of Energy (DOE) to establish a Multidisciplinary Simulation Center, with the mission to develop the next generation of exascale predictive simulation capabilities. The center will support the research of dozens of scientists, post-docs and students, and will foster close collaboration with researchers at Sandia National Laboratories, Los Alamos National Laboratory, and Lawrence Livermore National Laboratory.
Bob Moser and George Biros from the Oden Institute and UT’s Walker Department of Mechanical Engineering are leading the team of 18 faculty and senior researchers from six different departments, which also includes a faculty member from Texas State University. The new center is part of the Predictive Science Academic Alliance Program (PSAAP) and this is just the third time that PSAAP centers have been awarded by the DOE National Nuclear Security Administration (NNSA) since the program’s inception in 2008. UT Austin was one of only four institutions nationwide to be selected to establish a Multidisciplinary Simulation Center.
Five faculty members from the Department of Aerospace Engineering and Engineering Mechanics will be participating in the program: Noel Clemens, J. Tinsley Oden, Laxminarayan Raja, Philip Varghese and Karen Willcox.
“This shows the power of collaborative research and how it allows us to take on grand challenge problems,” Moser said. “The challenging research agenda called for by the DOE can only be achieved by drawing on strengths across campus in computational science, computer science, physics modeling, uncertainty quantification and physical experiments.”
The group will focus on developing predictive simulations of an inductively coupled plasma (ICP) torch in unprecedented detail. These torches have many applications, from advanced manufacturing to destruction of hazardous waste. An ICP torch experimental facility at UT Austin — originally developed by Varghese and Clemens for testing spacecraft heat shield materials — will be used to provide physical examples of a plasma torch flame. The ASE/EM team will perform various experiments using the torch which will be used to help develop the predictive simulations.
Plasma is considered to be the fourth fundamental state of matter — after solid, liquid, and gas. Plasmas and ionized gases display behaviors unlike other states of matter giving them unique properties. They occur in many natural situations, such as on the Sun and in lightning, and are used technologically, for example in arc lights and advanced manufacturing processes.
In an ICP torch, a gas flows through a strong oscillating electric field created by an oscillating magnetic field. Free electrons are accelerated by the electric field and heat the gas to very high temperatures — between 6000 and 10000 kelvins — greater than the temperature on the surface of the Sun.
To reliably simulate this kind of plasma torch, researchers will address issues of interest to the DOE and NNSA, such as thermal radiation; the chemical, thermodynamic and electrical properties of plasmas; turbulence; electromagnetic coupling; as well as uncertainties in computational modeling of complex systems.
Oden Institute researchers, including Oden and Willcox, will develop capabilities for predictive modeling and simulation of the plasma torch, while researchers from the Cockrell School of Engineering, including Varghese, Clemens and Raja, will conduct physical experiments. A key goal of the project is to combine the power of simulation and experiment to improve predictive capability.
Simulating the torch, however, is a means to a greater end. “It is a way to achieve the primary objective of the center: advancing predictive science capabilities,” Moser said.
The center’s capacity to advance predictive science is enabled by the supercomputing power and expertise available at the Texas Advanced Computing Center (TACC). Using systems such as TACC’s Frontera (the world’s most powerful academic supercomputer) in tandem with the DOE’s high-performance computing systems, the new predictive science center will also advance exascale computing: the next generation of the most powerful high-performance computing systems.
“There aren’t many universities that can compete for PSAAP grants,” Clemens said. “Having an organization like the Oden Institute, with its unique skillset and expertise, coupled with the supercomputing power offered by TACC, gives UT Austin the edge that allows us to tackle these really big problems.”
UT Austin’s new PSAAP III center is being supported through a $16.5 million DOE cooperative agreement over five years.
