Abstract:
The objective of this seminar is to present an overview of a multiscale multiphysics modeling concept of two- and multiphase flows, for application in safety analysis of advanced reactors in general, and Gen. IV Sodium Fast Reactor (SFR) in particular. The proposed methodology, under the development by a University Consortium (RPI, Columbia, University and SUNY at Stony Brook) allows for combining computational models of various scales, from molecular dynamics, through DNS to RANS, each using a different numerical solver, to simulate multiphysics phenomena governing the progression of reactor accidents. The component codes of the overall computational platform include: FronTier and PHASTA (both DNS codes), and NPHASE-CMFD (a multifield RANS code). The resultant multiple-code computational platform has been uploaded on several computers, including the Blue Gene supercomputers, and used to perform simulations of fuel element heat-up and failure, and fission gas injection into SFR coolant channels during a hypothetical loss of flow accident. The three codes model different overlapping parts of the overall physical problem, and use the boundary conditions which ensure proper interaction between the individual parts. Typical results of the simulations will be shown in the presentation. 
 
Brief biography:
Dr. Michael Podowski is a Professor of Nuclear Engineering and Engineering Physics in the Department of Mechanical, Aerospace and Nuclear Engineering, and Director of Center for Multiphase Research.  His research interests include fundamentals and applications of multiphase flow and heat transfer, computational multiphase flow dynamics (CMFD), dynamics and stability of multiphase systems and nuclear reactor thermal-hydraulics and safety. He is director and PI of the DOE-sponsored GNEP University Consortium for the Deployment of a Suite of High Performance Computational Tools for Multiscale Multiphysics Simulations of Generation-IV Reactors.
Recent and current research initiatives of Dr. Podowski include the following areas:
-  advanced nuclear reactors: Supercritical Water Reactor (SCWR), Very High Temperature Gas Reactor (VHTGR), and Fast Sodium Reactor (FSR),
-  computational multiphase fluid dynamics (CMFD) capabilities for nuclear reactors
-  fundamental physics of gas/liquid interfacial phenomena
-  stability analysis of BWRs and SCWRs
-  multiphase flow in chemical processing equipment for synthetic fuel production
-  microscale flow filtration systems
Professor Podowski has about 300 technical publications, including 7 books/book-chapters and over 50 journal papers. He is Fellow of American Nuclear Society (ANS).