R&D of the Next Generation Safety Analysis Methods for Fast Reactors With New Computational Science and Technology: Part 2 — Development and Verification of Thermo-Hydrodynamics Module of the COMPASS Code

2008 ◽  
Author(s):  
Yuichi Yamamoto ◽  
Etsujo Hirano ◽  
Masaya Oue ◽  
Sensuke Shimizu ◽  
Noriyuki Shirakawa ◽  
...  
Keyword(s):  
Conceptual Design ◽  
Computer Code ◽  
Computational Science ◽  
Unified Framework ◽  
Fast Reactors ◽  
Mps Method ◽  
Basic Functions ◽  
Moving Particle ◽  
The Moment ◽  
Complex Phenomena

A computer code, named COMPASS, is being developed employing the Moving Particle Semi-implicit (MPS) method for various complex phenomena of core disruptive accidents (CDAs) in sodium-cooled fast reactors (SFRs). The COMPASS is designed to analyze multi-physics problems involving thermal hydraulics, structure and phase change, in a unified framework of MPS method. In FY2006, development of the basic functions of the COMPASS was completed and fundamental verification calculations are being carried out at the moment. In this paper, we describe the conceptual design of COMPASS and the outline of the formulation of MPS method, and show the results of the basic verification calculations for thermo -hydrodynamics module.

Next Generation Safety Analysis Methods for SFRs—(3) Thermal Hydraulics Models of COMPASS Code and Experimental Analyses

2009 ◽  
Author(s):  
Yuichi Yamamoto ◽  
Etsujo Hirano ◽  
Masaya Oue ◽  
Sensuke Shimizu ◽  
Noriyuki Shirakawa ◽  
...  
Keyword(s):  
Phase Change ◽  
Computer Code ◽  
Fiscal Year ◽  
Thermal Hydraulics ◽  
Unified Framework ◽  
Mps Method ◽  
Basic Functions ◽  
Experimental Analyses ◽  
Moving Particle ◽  
Complex Phenomena

A computer code, named COMPASS, is being developed employing the Moving Particle Semi-implicit (MPS) method for various complex phenomena of core disruptive accidents (CDAs) in the sodium-cooled fast reactors (SFRs). The COMPASS is designed to analyze multi-physics problems involving thermal hydraulics, structure and phase change, in a unified framework of MPS method. In FYs2006 and 2007 (Japanese Fiscal Year, hereafter), the development of basic functions of COMPASS was completed and fundamental verification calculations were carried out. In FY2007, the integrated verification program using available experimental data for key phenomena in CDAs was also started. In this paper, we show the basic verification calculations for the phase change model of COMPASS and the results of experimental analyses, together with the outline of the formulation of MPS method and the conceptual design of the COMPASS code.

R&D of the Next Generation Safety Analysis Methods for Fast Reactors With New Computational Science and Technology: 1 — Introduction of the Project and Development of Structural Mechanics Module

2008 ◽  
Author(s):  
Seiichi Koshizuka ◽  
Jie Liu ◽  
Noriyuki Shirakawa ◽  
Yasushi Uehara ◽  
Masanori Naitoh ◽  
...  
Keyword(s):  
Science And Technology ◽  
Computer Code ◽  
Structural Mechanics ◽  
Ministry Of Education ◽  
Unified Framework ◽  
Fast Reactors ◽  
Mps Method ◽  
Sports Science ◽  
Moving Particle ◽  
Complex Phenomena

Sponsored by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan, a computer code, named COMPASS, has been developed employing the Moving Particle Semi-implicit (MPS) method for various complex phenomena of core disruptive accidents (CDAs) in sodium-cooled fast reactors (SFRs). The COMPASS is designed to analyze multi-physics problems involving thermal hydraulics, structure and phase change, in a unified framework of MPS method. In this and the following five papers [1–5], the outcomes of the project in FY2006 are presented. In FY2006, development of the basic functions of the COMPASS was completed and fundamental verification calculations were carried out. In this paper, the outline of the project and a part of COMPASS, the structural mechanics part, are described, including formulation of MPS method and the conceptual design of COMPASS, and the results of the basic verification calculations for structural mechanics module.

R&D of the Next Generation Safety Analysis Methods for Fast Reactors With New Computational Science and Technology: 6 — Study of Eutectic Reaction Between Metals: FPMD Approach

2008 ◽  
Author(s):  
Masashi Himi ◽  
Hiroshi Kozakai ◽  
Yuichi Yamamoto ◽  
Seigo Hosoda ◽  
Noriyuki Shirakawa ◽  
...  
Keyword(s):  
Eutectic Reaction ◽  
Computer Code ◽  
Safety Analysis ◽  
Computational Science ◽  
First Principle ◽  
Reactor Safety ◽  
Fast Reactors ◽  
Material Component ◽  
Metal Fuel ◽  
Moving Particle

A five-year research project started in FY2005 to develop a code based on the MPS (Moving Particle Semi-implicit) method for detailed analysis of core disruptive accidents (CDAs) in sodium-cooled fast reactors (SFRs). The code is named COMPASS (Computer Code with MPS for Reactor Safety Analysis) [1]. In this project, both mixed-oxide (MOX) and metal fuels are considered as a fuel material component. One of the main features of the project is to investigate eutectic reactions between the metal fuel and the cladding/structure materials with phase diagram calculation, classical and first principle molecular dynamics (CMD and FPMD) methods. This paper presents outcomes from study with FPMD.

R&D of the Next Generation Safety Analysis Methods for Fast Reactors With New Computational Science and Technology: 3 — Improvement of Basic Fluid Dynamics Models for the COMPASS Code

2008 ◽  
Author(s):  
Shuai Zhang ◽  
Koji Morita ◽  
Noriyuki Shirakawa ◽  
Yuichi Yamamoto
Keyword(s):  
Fluid Dynamics ◽  
Free Surface ◽  
Solution Algorithm ◽  
Pressure Solution ◽  
Next Generation ◽  
Fast Reactors ◽  
Mps Method ◽  
Basic Fluid ◽  
Moving Particle ◽  
Dynamics Models

A new next generation safety analysis code, COMPASS, is designed based on the moving particle semi-implicit (MPS) method to provide local information for various key phenomena in core disruptive accidents of sodium-cooled fast reactors. In FY2006, improvement of basic fluid dynamics models for the COMPASS code was carried out and verified with fundamental verification calculations. In order to improve the numerical stability of MPS simulations, a fully implicit pressure solution algorithm was introduced instead of the two-stage MAC algorithm originally applied by MPS. With a newly developed free surface model, numerical difficulty caused by poor pressure solutions is overcome by involving free surface particles in the pressure Poisson equation. An improved algorithm was also proposed for surface tension calculation with the continuous surface force (CSF) model applied to the moving particle method. This algorithm provides higher numerical precision with the CSF model by interpolation between moving particles and background mesh. Application of the fully Lagrangian MPS method to solid-fluid mixture flow problems is straightforward. In FY2006, applicability of the MPS method to interactions between fluid and multi-solid bodies was investigated in comparison with dam-break experiments with solid balls. It was found that a modified pressure solution algorithm makes simulation with the passively moving solid model stable numerically. Though characteristic behavior of solids was successfully reproduced by the present numerical simulations, the comparisons with the experimental results showed that interactions between solids and solid-wall should be modeled for more precise simulations. Therefore, the discrete element method will be considered in the next stage.

Detailed Analyses of Specific Phenomena in Core Disruptive Accidents of Sodium-Cooled Fast Reactors by the COMPASS Code

2010 ◽  
Author(s):  
Koji Morita ◽  
Shuai Zhang ◽  
Tatsumi Arima ◽  
Seiichi Koshizuka ◽  
Yoshiharu Tobita ◽  
...  
Keyword(s):  
Computer Code ◽  
Failure Criteria ◽  
Low Energy ◽  
Fast Reactors ◽  
Solid Mixture ◽  
Duct Wall ◽  
Fuel Pin ◽  
Metal Fuel ◽  
Molten Materials ◽  
Moving Particle

A five-year research project has been initiated in 2005 to develop a code based on the MPS (Moving Particle Semi-implicit) method for detailed analysis of specific phenomena in core disruptive accidents (CDAs) of sodium-cooled fast reactors (SFRs). The code is named COMPASS (Computer Code with Moving Particle Semi-implicit for Reactor Safety Analysis). The specific phenomena include 1) fuel pin failure and disruption, 2) molten pool boiling, 3) melt freezing and blockage formation, 4) duct wall failure, 5) low-energy disruptive core motion, 6) debris-bed coolability, and 7) metal-fuel pin failure. Validation study of COMPASS is progressing for these key phenomena. In this paper, recent COMPASS results of detailed analyses for the several specific phenomena are summarized. Simulations of GEYSER and THEFIS experiments were performed for dispersion and freezing behaviors of molten materials in narrow flow channels. In particular, the latter experiment using melt-solid mixture is also related to fundamental behavior of low energy disruptive core. CABRI-TPA2 experiment was simulated for boiling behavior of molten core pool. Expected mechanism of heat transfer between molten fuel and steel mixture was reproduced by the simulation. Analyses of structural dynamics using elastoplastic mechanics and failure criteria were performed for SCARABEE BE+3 and CABRI E7 experiments. These two analyses are especially focused on thermal and mechanical failure of steel duct wall and fuel pin, respectively. The present results demonstrate COMPASS will be useful to understand and clarify the specific phenomena of CDAs in SFRs in details.

scholarly journals LNG Tank Sloshing Simulation of Multidegree Motions Based on Modified 3D MPS Method

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Chunhui Wang ◽  
Chunyu Guo ◽  
Fenglei Han
Keyword(s):  
Free Surface ◽  
Weighted Average ◽  
Kernel Functions ◽  
Computational Stability ◽  
Mps Method ◽  
Fluid Sloshing ◽  
Particle Hydrodynamics ◽  
Moving Particle ◽  
Lng Tank ◽  
Stability And Accuracy

Modified 3D Moving Particle Semi-Implicit (MPS) method is used to complete the numerical simulation of the fluid sloshing in LNG tank under multidegree excitation motion, which is compared with the results of experiments and 2D calculations obtained by other scholars to verify the reliability. The cubic spline kernel functions used in Smoothed Particle Hydrodynamics (SPH) method are adopted to reduce the deviation caused by consecutive two times weighted average calculations; the boundary conditions and the determination of free surface particles are modified to improve the computational stability and accuracy of 3D calculation. The tank is under forced multidegree excitation motion to simulate the real conditions of LNG ships, the pressures and the free surfaces at different times are given to verify the accuracy of 3D simulation, and the free surface and the splashed particles can be simulated more exactly.

A domain decomposition strategy for hybrid parallelization of moving particle semi-implicit (MPS) method for computer cluster

2015 ◽  
Vol 18 (4) ◽  
pp. 1363-1377 ◽  
Author(s):  
Davi Teodoro Fernandes ◽  
Liang-Yee Cheng ◽  
Eric Henrique Favero ◽  
Kazuo Nishimoto
Keyword(s):  
Domain Decomposition ◽  
Computer Cluster ◽  
Mps Method ◽  
Hybrid Parallelization ◽  
Moving Particle

Optimization of Moving Particle Semi-Implicit (MPS) Method and Studying of Flow Instability

2018 ◽  
Author(s):  
Kailun Guo ◽  
Ronghua Chen ◽  
Suizheng Qiu ◽  
Wenxi Tian ◽  
Guanghui Su ◽  
...  
Keyword(s):  
Multiphase Flows ◽  
Flow Instability ◽  
Free Particle ◽  
Particle Method ◽  
Severe Accident ◽  
Particle Methods ◽  
Two Phase ◽  
Mps Method ◽  
Viscosity Term ◽  
Moving Particle

Multiphase flow widely exists in the nature and engineering. The two-phase flow is the highlight of the studies about the flow in the vessel and steam explosion in nuclear severe accidents. The Moving Particle Semi-implicit (MPS) method is a fully-Lagrangian particle method without grid mesh which focuses on tracking the single particle and concerns with its movement. It has advantages in tracking complex multiphase flows compared with gird methods, and thus shows great potential in predicting multiphase flows. The objective of this thesis is to develop a general multiphase particle method based on the original MPS method and thus this work is of great significance for improving the numerical method for simulating the instability in reactor severe accident and two-phase flows in vessel. This research is intended to provide a study of the instability based on the MPS method. Latest achievements of mesh-free particle methods in instability are researched and a new multiphase MPS method, which is based on the original one, for simulating instability has been developed and validated. Based on referring to other researchers’ papers, the Pressure Poisson Equation (PPE), the viscosity term, the free surface particle determination part and the surface tension model are optimized or added. The numerical simulation on stratification behavior of two immiscible flows is carried out and results are analyzed after data processing. It is proved that the improved MPS method is more accurate than the original method in analysis of multiphase flows. In this paper, the main purposes are simulating and discussing Rayleigh-Taylor (R-T) instability and Kelvin-Helmholtz (K-H) instability. R-T and K-H instability play an important role in the mixing process of many layered flows. R-T instability occurs when a lower density fluid is supported by another density higher fluid or higher density fluid is accelerated by lower density fluid, and the resulting small perturbation increases and eventually forms turbulence. K-H instability is a small disturbance for two different densities, such as waves, at the interface of the two-phase fluid after giving a fixed acceleration in the fluid. Turbulence generated by R-T instability and K-H instability has an important effect in applications such as astrophysics, geophysics, and nuclear science.

Simulation of Multiliquid-Layer Sloshing With Vessel Motion by Using Moving Particle Semi-Implicit Method

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Kyung Sung Kim ◽  
Moo-Hyun Kim ◽  
Jong-Chun Park
Keyword(s):  
Gas Production ◽  
Particle Simulation ◽  
Small Scale ◽  
Linear Potential ◽  
Operational Effectiveness ◽  
Mps Method ◽  
Moving Particle ◽  
Vessel Motion ◽  
Linear Potential Theory ◽  
Oil Gas

For oil/gas production/processing platforms, multiple liquid layers can exist and their respective sloshing motions can also affect operational effectiveness or platform performance. To numerically simulate those problems, a new multiliquid moving particle simulation (MPS) method is developed. In particular, to better simulate the relevant physics, robust self-buoyancy model, interface searching model, and surface-tension model are developed. The developed multiliquid MPS method is validated by comparisons against experiment in which three-liquid-sloshing experiment and the corresponding linear potential theory are given. The validated multiliquid MPS program is subsequently coupled with a vessel-motion program in time domain to investigate their dynamic-coupling effects. In case of multiple liquid layers, there exists a variety of sloshing natural frequencies for respective interfaces, so the relevant physics can be much more complicated compared with the single-liquid-tank case. The simulation program can also reproduce the detailed small-scale interface phenomenon called Kelvin–Helmholtz instability. The numerical simulations also show that properly designed liquid cargo tank can also function as a beneficial antirolling device.

Numerical Analysis of the Corium Behavior Within the Fuel Support Piece by MPS

2016 ◽  
Author(s):  
Ronghua Chen ◽  
Lie Chen ◽  
Wenxi Tian ◽  
Guanghui Su ◽  
Suizheng Qiu
Keyword(s):  
Eutectic Reaction ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Severe Accident ◽  
Guide Tube ◽  
Melt Flow ◽  
Control Rod ◽  
Mps Method ◽  
Moving Particle ◽  
Accident Conditions

In the typical boiling water reactor (BWR), each control rod guide tube supports four fuel assemblies via an orificed fuel support piece in which a channel is designed to be a potential corium relocation path from the core region to the lower head under severe accident conditions. In this study, the improved Moving Particle Semi-implicit (MPS) method was adopted to analyze the melt flow and ablation behavior in this region during a severe accident of BWR. A three-dimensional particle configuration was constructed for analyzing the melt flow behavior within the fuel support piece. Considering the symmetry of the fuel support piece, only one fourth of the fuel support was simulated. The eutectic reaction between Zr (the material of the corium) and stainless steel (the material of the fuel support piece) was taken into consideration. The typical melt flow and freezing behaviors within the fuel support piece were successfully reproduced by MPS method. In all the simulation cases, the melt discharged from the hole of the fuel support piece instead of plugging the fuel support piece. The results indicate that MPS method has the capacity to analyze the melt flow and solidification behavior in the fuel support piece.

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