Exact Difference Schemes and Recent Advances in Coarse Mesh Methods for Thermal Hydraulics

uddin
SPEAKER:
Rizwan-uddin
Department of Nuclear, Plasma, and Radiological Engineering
University of Illinois at Urbana-Champaign
DATE/TIME:
FRI, 03/18/2022 - 3:00PM TO 4:00PM
LOCATION:
Zoom
Spring 2022 Colloquium Series
Abstract:

Roots of coarse mesh, or advanced, nodal methods [1] can be traced to “exact finite difference schemes.” After a brief overview of exact finite difference schemes, a nodal scheme will be developed for the scalar convection-diffusion PDE [2].

To address some of the limitations on classical nodal schemes, our efforts have focused on the development of: 1) a modified nodal method for the time-dependent Navier-Stokes (N-S) equations and its parallel implementation [3]; 2) methods for domains with curved boundaries [4, 5]; and 3) adaptive mesh refinement (AMR) capability for nodal schemes. The modified nodal method for the time-dependent, incompressible N-S equations incorporates two major modifications over nodal schemes developed earlier. First, rather than using the conventional continuity equation or the vorticity-stream function formulation, we replace the conventional continuity equation by a Poisson-type continuity equation written in terms of pressure, and retain the momentum equations in primitive variables. The second modification is introduced in the development of the numerical scheme. Here, rather than using only the diffusion term to obtain the homogeneous part of the solution of the momentum equations, a “linearized” convection term—based on previous time step velocity—is also retained on the left hand side of the transverse-integrated equations, leading to a local homogeneous solution for the transverse-integrated velocities in each spatial direction that is a combination of a constant, a linear and an exponential term.

Current work to remove the restrictions on domain geometry is focused on two approaches: 1) hybrid scheme in which nodal methods are restricted to the interior of the domains and along boundaries that are parallel to the coordinate axes, while a second scheme—such as finite element, more suitable for complex boundaries—is used along curved boundaries [4]; 2) iso-parametric mapping approach to transform the hexahedral elements to a simple cube on which traditional NIM can be applied [5].

1. R. D. Lawrence, “Progress in Nodal Methods for the Solution of the Neutron Diffusion and Transport Equations,” Progress in Nuclear Energy, 17 (3), 271 (1986).
2. Rizwan-uddin, “Comparison of the Nodal Integral Method and Non-Standard Finite-Difference Schemes for the Fisher Equation,” SIAM J. Scientific Computing, 22 (6), 1926-1942 (2001).
3. Fei Wang and Rizwan-uddin, “A Modified Nodal Scheme for the Time-Dependent, Incompressible Navier-Stokes Equations,” J. Comp. Physics, 187, 168-196 (2003).
4. Sundar Namala and Rizwan-uddin, "Hybrid Nodal Integral -Finite Element Method (NI-FEM) for 2D, Time-Dependent Burgers’ Equation in Arbitrary Geometries", Proc. of the Int. Topical Meeting on Nuclear Reactor Thermal Hydraulics, 3741-3755, Portland, OR, August 25-29, 2019.
5. Ibrahim Jarrah and Rizwan-uddin, "Nodal integral methods in general 2D curvilinear coordinates - applied to convection–diffusion equation in domains discretized using quadrilateral elements”, Int. J Heat and Mass Transfer 187 (2022) 122559, https://doi.org/10.1016/j.ijheatmasstransfer.2022.122559.

Virtual Education and Research Lab (VERL):
At VERL, we develop models to simulate physical phenomena, and solve them analytically and on high performance computers to simulate all aspects of processes taking place in and related to reactors and nuclear power plants (including neutronics, thermal hydraulics, etc). Recent focus has been on advanced numerical schemes for Computational Fluid Dynamics (CFD) as well as on multi-scale, multi-physics approaches achieved by coupling multiple codes. We also develop virtual, 3D, immersive and interactive models of facilities such as nuclear power plants, control rooms and laboratories, to help design better human-machine-interfaces, facilitate efficient design, and improve education and training. A recent addition to our portfolio is digital instrumentation and control and cyber security in the nuclear industry. This extension is being pursued in collaboration with the cyber security expertise available at the Coordinated Science Lab at the University of Illinois.

About the Speaker:

Dr Rizwan Uddin is Professor and Head of Nuclear, Plasma, and Radiological Engineering Department; Professor of Computational Science and Engineering; and Director of Master of Engineering in Energy Systems program at the University of Illinois at Urbana-Champaign. His areas of interest include thermal hydraulics; CFD; computational methods development; coupled neutronics and thermal hydraulics; biological systems and general modeling and simulation. With guidance from his undergraduate and graduate students, he has also been exploring the use of computer- and video-games for education and training. Recipient of numerous awards, he is also a fellow of the American Nuclear Society.

Networked Radiation Detection in Urban Environments

RenCooper
SPEAKER:
Dr. Ren Cooper
Staff Applied Physicist
Lawrence Berkeley National Laboratory
DATE/TIME:
Fri, 03/04/2022 - 3:00PM TO 4:00PM
LOCATION:
3105 ETCHEVERRY HALL
Spring 2022 Colloquium Series
Abstract:

The ability to detect, identify, and localize illicit radiological/nuclear sources in urban environments is a key component of nuclear security and nuclear non-proliferation efforts across the world. Recent advances in sensing, telecommunications, and edge and cloud computing have led to renewed interest in employing detector networks to provide enhanced detection performance and increased domain awareness. This presentation will describe efforts to exploit multi-sensor fusion and networked sensing towards the development of new capabilities for radiation detection in urban environments.

About the Speaker:

Ren Cooper is a Staff Applied Physicist and Deputy Head of the Applied Nuclear Physics Program in the Nuclear Science Division at Lawrence Berkeley National Laboratory (LBNL). He received B.Sc., M.Sc., and Ph.D. degrees from The University of Liverpool, UK and joined LBNL in November 2011 following three years of postdoctoral research at Oak Ridge National Laboratory. Ren specializes in the development of novel radiation detection and imaging systems and algorithms for fundamental physics, nuclear safeguards, nuclear safety, and nuclear security. He currently leads research projects that include the development of new High Purity Germanium (HPGe) detectors, the development of advanced technologies for vehicle-based radiation detection and imaging systems, and the exploration of new systems and methods for networked radiation detection.

Is Nuclear Clean?

MLDunzikGougar
SPEAKER:
Mary Lou Dunzik-Gougar
Ph.D. - Associate Professor, Associate Dean, Reactor Administrator, and American Nuclear Society President
DATE/TIME:
FRI, 02/25/2022 - 3:00PM TO 4:00PM
LOCATION:
zoom
Spring 2022 Colloquium Series
Abstract:

 

About the Speaker:

Dunzik-Gougar has a B.S. in chemistry from Cedar Crest College and received an M.S. in environmental engineering along with her Ph.D. in nuclear engineering from Pennsylvania State University. Her research interests include the nuclear fuel cycle, nuclear fuels and materials development, spent fuel processing, and waste form development.

In 2011 and 2014, she was the recipient of ANS Presidential Citations in addition to the Landis Public Communication and Education Award in 2014.

For a Safer Nuclear Outlook: Learning from Experience within an Adaptive & Generic Probabilistic Safety Assessment Framework

Ali Ayoub portrait
SPEAKER:
Dr. Ali Ayoub
Postdoctoral Associate, Department of Nuclear Science and Engineering, ​Massachusetts Institute of Technology (MIT)
DATE/TIME:
Fri, 02/18/2022 - 3:00PM TO 4:00PM
LOCATION:
3105 ETCHEVERRY HALL
Spring 2022 Colloquium Series
Abstract:

The worldwide civil nuclear operations have accumulated more than 19’000 reactor-years of experience providing substantial amounts of data and knowledge. With the goal of more intensively learn from this experience to verify and improve the level of nuclear safety, this talk presents the research carried out at the ETH Zurich covering the following inter-woven parts:

1) The continued development and establishment of a novel open comprehensive nuclear events database; 2) subsequent event and statistical analysis to learn from the past and extract lessons, in particular, for 3) the development of generic & simplified Probabilistic Safety Assessment (PSA) models, with a main motivation of enabling large-scale precursor analysis, and 4) exploiting the simplified PSA models and the performed large scale precursor analyses to offer a comprehensive statistical study of the operational risk in the civil nuclear sector.

About the Speaker:

Dr. Ali Ayoub is currently a postdoctoral researcher at the Department of Nuclear Science and Engineering at the Massachusetts Institute of Technology (MIT). He received his PhD (2021) and MSc (2018) in Nuclear Engineering from the Swiss Federal Institute of Technology Zurich (ETH Zurich). He has worked and published on various research topics including probabilistic risk assessment (PRA), precursor analysis, uncertainty quantification, safety culture, and risk communication. His general research interests are around the area of risk analysis, nuclear and critical infrastructures safety, resilience engineering, decision-making, and energy policy.

Hi Vo, our former grad student and NSSC fellow awarded a LANL directors funded post doc.

Hi Vo, our former grad student and NSSC fellow awarded a LANL directors funded post doc.

February 11th, 2022

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Across all divisions, the LANL postdocs went through a competitive process in order to be selected for the fellowship based on previous research merit and the strength of the postdoc research proposal.
Director Postdoc fellowship provides full, 2/3, 1/3 funding for each subsequent year to support Hi Vo's research proposal.
Hi Vo's Director funded research proposal is on the exploration of unit and collective plastic deformation processes using in situ 4DSTEM mechanical testing and 3D-EBSD.

Congratulations Hi Vo! What a wonderful achievement!

Peter Hosemann, Professor and Chair chosen as 2022 TMS Brimacombe Medalist Award Winner

Peter Hosemann, Professor and Chair chosen as 2022 TMS Brimacombe Medalist Award Winner

February 10th, 2022

Music to Ears GoDaddy Store Image (1)

The Brimacomb award award recognizes Professor Hosemann for his sustained excellence and achievements in materials science and engineering, and his record of continuing service to the profession. He received this award specifically for his contribution to micro and macroscale mechanical testing of irradiated materials and in-situ materials testing and continued dedication to TMS and education. Professor Hosemann is a dedicated member to the Minerals, Metals and Materials society which is also a professional home of a wide range of nuclear materials topics.........More Info about the award

The formal presentation of the award will be at the TMS-AIME Annual Awards Ceremony on Wednesday, March 3, during the TMS 2022 Annual Meeting in Anaheim, California. 

Congratulations Professor and Chair Peter Hosemann!

From Superheavy Elements to the Stockpile: The Journey of a Cal Grad

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SPEAKER:
Dr. Sarah Nelson
DATE/TIME:
Fri, 02/04/2022 - 3:00PM TO 4:00PM
LOCATION:
zoom
Spring 2022 Colloquium Series
Abstract:

TBD

About the Speaker:

Dr. Sarah Nelson, a nuclear and radiochemist, serves as the Director (Acting) for the Office of Experimental Sciences for the National Nuclear Security Administration’s (NNSA) Office of Research, Development, Test, and Evaluation (NA-11), including Academic Programs. Sarah joined Defense Programs in mid-November 2015 as the office Deputy Director.

Sarah earned her bachelor’s degree in chemistry with Distinction from the University of California, Santa Barbara. She earned her doctorate in chemistry from the University of California, Berkeley with Professor Heino Nitsche.

Prior to joining NNSA, Sarah completed postdoctoral research as a Roger Batzel fellow at Lawrence Livermore National Laboratory, and afterward as a staff scientist for Pacific Northwest National Laboratory on assignment to the Defense Threat Reduction Agency. Sarah also was selected as a Christine Mirzayan Science & Technology Policy Fellow of The National Academies for the Winter 2012 assisting the Board on Physics and Astronomy.

She has received numerous awards including US DOE Secretary’s Achievement Award, DTRA/US STRATCOM Center for Combatting Weapons of Mass Destruction Director’s Award for Public Service, LLNL’s Excellence in Publication Award in Basic Science, and the Gordon Battelle Prize for Scientific Discovery.

 

Recent inertial confinement fusion experiments at NIF reaching 1.35 MJ and the Lawson criterion for ignition

AnnieKritcher
SPEAKER:
DR. ANDREA (ANNIE) L. KRITCHER
DATE/TIME:
FRI, 01/28/2022 - 3:00PM TO 4:00PM
LOCATION:
via Zoom
Spring 2022 Colloquium Series
Abstract:

The inertial fusion community have been working towards ignition for decades, since the idea of inertial confinement fusion (ICF) was first proposed by Nuckolls, et al., in 1972. On August 8, 2021, the Lawson criterion for ignition was finally demonstrated in the laboratory on the National Ignition Facility (NIF) in Northern California. The experiment, N210808, produced a fusion yield of 1.35 MJ from 1.9 MJ of laser energy and appears to have crossed the tipping-point of thermodynamic instability according to several ignition metrics. The “indirect” ICF approach at NIF described in this talk uses a hohlraum radiation cavity to heat and ablate the outside of a capsule that contains Deuterium-Tritium (DT) fusion fuel. This ablation causes the fuel to accelerate inward (implode) at high velocities doing work on a central lower density “hot spot” of DT fuel, increasing the temperature and density of the hot spot to the extreme conditions required for fusion. This presentation discusses the development of a platform that increased the hot-spot energy and hot-spot pressure, to achieve record ICF performance.

About the Speaker:

Dr. Annie Kritcher is the HYBRID-E design lead within the ICF program and is a member of the ICF leadership team. She serves as team lead for integrated implosion modeling and is a group leader within the design physics division at LLNL. Annie started at the Lab as a summer intern in 2004, was an LLNL Lawrence Scholar during her time at UC Berkeley, and was a Lawrence postdoctoral fellow in 2009 following completion of her Ph.D. Her current main areas of interest include the design and analysis of inertial confinement fusion experiments (ICF) and high energy density plasmas. She is also interested in extreme equations of state (EOS) measurements. Her work has led to both the highest fusion yields (>1.35 MJ) and the highest EOS measurements ever achieved in the laboratory.

 

 

 

With great sadness of the passing of Hans Mark

With great sadness of the passing of Hans Mark

January 5th, 2022

Portrait of DoD Mr. Mark Hans Director, Defense Research and Engineering  (U.S. Army photo by Mr. Scott Davis) (Released) (PC-193032)

Hans Mark, who served as chair of the Department of Nuclear Engineering and administrator of the Berkeley Research Reactor from 1964 to 1969, died Saturday, Dec. 18, at the age of 92. Mark was a giant in his field, serving as NASA Deputy Administrator, Secretary of the Air Force, Director of Defense Research and Engineering in the Department of Defense, and Chancellor of the University of Texas system. He was a Berkeley alum and a long-time benefactor of the department. Read more about his remarkable life and work here.

Don Olander and Light Water Reactor Materials: A Personal Memoir and Tribute

Arthur Motta
SPEAKER:
Arthur Motta
DATE/TIME:
FRI, 12/03/2021 - 4:00PM TO 5:30PM
LOCATION:
Bancroft Hotel
Fall 2021 Colloquium Series
Abstract:

This talk is an homage to Don Olander, as a special tribute to the enormous influence he has had on a whole generation of nuclear materials scientists, and a remembrance of my time at UC Berkeley, working under his supervision. The talk focuses also on the co-writing of the textbook “Light Water Reactor Materials” recently published by the ANS.

About the Speaker:

Arthur Motta is Professor of Nuclear Engineering and Materials Science and Engineering at Penn State University. He holds Ph.D. in Nuclear Engineering from the University of California, Berkeley. Prof. Motta works in the area of radiation damage and environmental degradation to materials with specific emphasis in zirconium alloys. Prof. Motta is a Fellow of the American Nuclear Society (ANS) and received the Mishima Award from the ANS for outstanding contributions in research and development work on nuclear fuel and materials, as well as the ASTM William J. Kroll Medal for sustained impactful contributions to zirconium metallurgy. With his thesis advisor Don Olander he co-wrote the textbook “Light Water Reactor Materials” published by ANS in two volumes.