311 The effect of the general-purpose structural analysis tool in design and research education

2009 ◽  
Vol 2009 (0) ◽  
pp. _311-1_-_311-4_
Author(s):  
Koji SEKINE
Keyword(s):  
Structural Analysis ◽  
General Purpose ◽  
Analysis Tool ◽  
Research Education

Coupling of a Reactor Analysis Code and a Lower Head Thermal Analysis Solver

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Hiroshi Madokoro ◽  
Alexei Miassoedov ◽  
Thomas Schulenberg
Keyword(s):  
Structural Analysis ◽  
Message Passing ◽  
Message Passing Interface ◽  
Severe Accident ◽  
Coupled Analysis ◽  
Accident Analysis ◽  
Analysis Tool ◽  
Lower Head ◽  
Calculation Results ◽  
Reactor Pressure

Due to the recent high interest on in-vessel melt retention (IVR), development of detailed thermal and structural analysis tool, which can be used in a core-melt severe accident, is inevitable. Although RELAP/SCDAPSIM is a reactor analysis code, originally developed for U.S. NRC, which is still widely used for severe accident analysis, the modeling of the lower head is rather simple, considering only a homogeneous pool. PECM/S, a thermal structural analysis solver for the reactor pressure vessel (RPV) lower head, has a capability of predicting molten pool heat transfer as well as detailed mechanical behavior including creep, plasticity, and material damage. The boundary condition, however, needs to be given manually and thus the application of the stand-alone PECM/S to reactor analyses is limited. By coupling these codes, the strength of both codes can be fully utilized. Coupled analysis is realized through a message passing interface, OpenMPI. The validation simulations have been performed using LIVE test series and the calculation results are compared not only with the measured values but also with the results of stand-alone RELAP/SCDAPSIM simulations.

An Advanced Unstructured-Grid Finite-Volume Design System for Gas Turbine Combustion Analysis

2013 ◽  
Author(s):  
M. S. Anand ◽  
R. Eggels ◽  
M. Staufer ◽  
M. Zedda ◽  
J. Zhu
Keyword(s):  
Finite Volume ◽  
Compressible Flows ◽  
Turbulence Models ◽  
General Purpose ◽  
Navier Stokes ◽  
Design System ◽  
Analysis Tool ◽  
Combustion Chemistry ◽  
Finite Volume Approach ◽  
Complicated Geometries

A general-purpose combustion Computational Fluid Dynamics (CFD) design analysis tool has been developed. The method is pressure-based and applicable to both incompressible and compressible flows. The unstructured finite-volume approach used can take arbitrary shapes of mesh cells to resolve complicated geometries. Turbulence is simulated either by Reynolds-Averaged Navier-Stokes (RANS) or by Large Eddy Simulation (LES) approaches. Combustion is modeled by various combinations of combustion chemistry and combustion-turbulence models including transport probability density function (PDF) model. A Lagrangian approach is used to simulate fuel spray droplet. The resulting tool has being used in routine combustor simulations for a variety of commercial and military combustor development programs. Application examples presented include simulations of several combustors and comparisons with available rig data.

scholarly journals A thermal structural analysis tool for RPV lower head behavior during severe accidents with core melt

2018 ◽  
Vol 4 (0) ◽  
pp. 18-00038-18-00038 ◽  
Author(s):  
Hiroshi MADOKORO ◽  
Alexei MIASSOEDOV ◽  
Thomas SCHULENBERG
Keyword(s):  
Structural Analysis ◽  
Analysis Tool ◽  
Severe Accidents ◽  
Lower Head

scholarly journals A Universal Nonparametric Event Detection Framework for Neuropixels Data

2019 ◽  
Author(s):  
Hao Chen ◽  
Shizhe Chen ◽  
Xinyi Deng
Keyword(s):  
Change Point ◽  
Large Scale ◽  
Brain Regions ◽  
General Purpose ◽  
Electrophysiological Recording ◽  
Neural Population ◽  
Data Sets ◽  
Analysis Tool ◽  
Neural Activities ◽  
Spontaneous Behavior

SummaryNeuropixels probes present exciting new opportunities for neuroscience, but such large-scale high-density recordings also introduce unprecedented challenges in data analysis. Neuropixels data usually consist of hundreds or thousands of long stretches of sequential spiking activities that evolve non-stationarily over time and are often governed by complex, unknown dynamics. Extracting meaningful information from the Neuropixels recordings is a non-trial task. Here we introduce a general-purpose, graph-based statistical framework that, without imposing any parametric assumptions, detects points in time at which population spiking activity exhibits simultaneous changes as well as changes that only occur in a subset of the neural population, referred to as “change-points”. The sequence of change-point events can be interpreted as a footprint of neural population activities, which allows us to relate behavior to simultaneously recorded high-dimensional neural activities across multiple brain regions. We demonstrate the effectiveness of our method with an analysis of Neuropixels recordings during spontaneous behavior of an awake mouse in darkness. We observe that change-point dynamics in some brain regions display biologically interesting patterns that hint at functional pathways, as well as temporally-precise coordination with behavioral dynamics. We hypothesize that neural activities underlying spontaneous behavior, though distributed brainwide, show evidences for network modularity. Moreover, we envision the proposed framework to be a useful off-the-shelf analysis tool to the neuroscience community as new electrophysiological recording techniques continue to drive an explosive proliferation in the number and size of data sets.

Implementation of Engine Loss Analysis Methods in the Numerical Propulsion System Simulation

2005 ◽  
Author(s):  
Bryce A. Roth ◽  
Erin M. McClure ◽  
Travis W. Danner
Keyword(s):  
System Simulation ◽  
Engine Performance ◽  
General Purpose ◽  
Propulsion System ◽  
Accurate Estimation ◽  
Analysis Tool ◽  
Cycle Model ◽  
Loss Analysis ◽  
Analysis Methods ◽  
Engine Cycle

This paper describes the implementation and application of a new set of thermodynamic loss analysis tools in the Numerical Propulsion System Simulation. This analysis tool set is intended to enable fast, accurate estimation of losses in an engine cycle model with minimal effort on the part of the user. The basic thermodynamic concepts and analysis methods are first described. Next, the implementation of the necessary thermodynamic calculation functions is described. These functions are intended to be used in conjunction with a general-purpose loss analysis element to facilitate estimation of all losses in an engine cycle model. The loss analysis element is described in detail and is subsequently used to analyze a mixed flow turbofan engine. Typical performance and loss results are presented. The resultant detailed loss information is not normally available when using standard cycle analysis methods. The information gained from this analysis is useful in that it yields insight into the underlying losses that contribute to the overall engine performance.

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