6 research outputs found
Recommended from our members
Scaling to 150K cores: recent algorithm and performance engineering developments enabling XGC1 to run at scale
Particle-in-cell (PIC) methods have proven to be eft#11;ective in discretizing the Vlasov-Maxwell system of equations describing the core of toroidal burning plasmas for many decades. Recent physical understanding of the importance of edge physics for stability and transport in tokamaks has lead to development of the fi#12;rst fully toroidal edge PIC code - XGC1. The edge region poses special problems in meshing for PIC methods due to the lack of closed flux surfaces, which makes fi#12;eld-line following meshes and coordinate systems problematic. We present a solution to this problem with a semi-#12;field line following mesh method in a cylindrical coordinate system. Additionally, modern supercomputers require highly concurrent algorithms and implementations, with all levels of the memory hierarchy being effe#14;ciently utilized to realize optimal code performance. This paper presents a mesh and particle partitioning method, suitable to our meshing strategy, for use on highly concurrent cache-based computing platforms
Recommended from our members
Fiscal Year 2007
This work is aimed at developing an experimentally validated computational capability for understanding the complex processes governing the performance of solvent extraction devices used for separations in nuclear fuel reprocessing. These applications pose a grand challenge due to the combination of complicating factors in a three-dimensional, turbulent, reactive, multicomponent, multiphase/interface fluid flow system. The currently limited process simulation and scale-up capabilities provides uncertainty in the ability to select and design the separations technology for the demonstration plan of the Global Nuclear Energy Partnership (GNEP) program. We anticipate the development of science-based models for technology development and design. This project will position ORNL to address the emerging opportunity by creating an expandable process model validated experimentally. This project has three major thrusts, namely, a prototype experimental station, a continuum modeling and simulation effort, and molecular modeling and kinetics support. Excellent progress has been made in corresponding activities in this first year in: (1) defining, assembling, and operating a relevant prototype system for model validation; (2) establishing a mathematical model for fluid flow and transport; (3) deploying sub-scale molecular modeling
FY 2007 LDRD Director's R&D Progress SummaryProposal Title: Developing a Science Base for Fuel Reprocessing Separations in the Global Nuclear Energy Program
This work is aimed at developing an experimentally validated computational capability for understanding the complex processes governing the performance of solvent extraction devices used for separations in nuclear fuel reprocessing. These applications pose a grand challenge due to the combination of complicating factors in a three-dimensional, turbulent, reactive, multicomponent, multiphase/interface fluid flow system. The currently limited process simulation and scale-up capabilities provides uncertainty in the ability to select and design the separations technology for the demonstration plan of the Global Nuclear Energy Partnership (GNEP) program. We anticipate the development of science-based models for technology development and design. This project will position ORNL to address the emerging opportunity by creating an expandable process model validated experimentally. This project has three major thrusts, namely, a prototype experimental station, a continuum modeling and simulation effort, and molecular modeling and kinetics support. Excellent progress has been made in corresponding activities in this first year in: (1) defining, assembling, and operating a relevant prototype system for model validation; (2) establishing a mathematical model for fluid flow and transport; (3) deploying sub-scale molecular modeling