Numerical Simulation of Debris Bed Relocation Behavior in Sodium-Cooled Fast Reactor

2018 ◽  
Author(s):  
Chunming Teng ◽  
Bin Zhang ◽  
Jianqiang Shan
Keyword(s):  
Shear Strength ◽  
Fast Reactor ◽  
Simulation Analysis ◽  
Soil Mechanics ◽  
Great Influence ◽  
Transition Process ◽  
Effective Implementation ◽  
Debris Particles ◽  
Cooling Ability ◽  
Good Agreement

For the core disruptive accident (CDA) of sodium-cooled fast reactor (SFR), the molten fuel or steel is solidified into debris particles which form debris bed in the lower plenum. When the boiling occurs inside debris bed, the flow of coolant and vapor makes debris relocated and flattened, which called debris relocation. The thickness of debris bed has great influence to the cooling ability of fuel debris in low plenum. To ensure the effective implementation of the in-vessel retention (IVR), it’s very necessary to evaluate the transient changes of shape and thickness in relocation behavior for CDA simulation analysis. To simulate relocation behavior, a debris relocation model based on COMMEN code was developed in this paper. The debris relocation model was established based on the extrapolation of the shear strength mechanism, which was originally proposed and widely applied in soil mechanics filed. Shear strength is a function of the particles’ density and position. Debris bed is fluidized only when the shear stress in particle unit is larger than shear strength of debris particles. By integrating the debris relocation model into the COMMEN code, the transition process of the bed in depressurization experiments was simulated and compared against the experimental results. Good agreement shows that the debris relocation model presented in this paper can reasonably simulate the relocation behavior.

HTR-PM Simulation Analysis of Accident Conditions Based on vPower Platform

2014 ◽  
Author(s):  
Tang Yang ◽  
Yangping Zhou ◽  
Zhiwei Zhou ◽  
Zhang Dabin
Keyword(s):  
Simulation Analysis ◽  
Mutual Influence ◽  
Reactor Power ◽  
Steam Generators ◽  
Water Steam ◽  
Steady State Operation ◽  
Design Values ◽  
Accident Conditions ◽  
Good Agreement ◽  
Rankin Cycle

HTR engineering simulator can be achieved by embedding THERMIX code into the vPower simulation environment. The engineering simulator consists of double-module reactors, two steam generators and entire secondary loop system for power generation with a water-steam Rankin cycle. The engineering simulator can be applied to simulate the steady-state operation, but also transient and accident state of HTR-PM. This paper analyzes the trends of reactor power, helium flow, steam generator inlet parameters, turbine inlet parameters and other key parameters under accident conditions, as well as the mutual influence between the two module reactors during accident process. Current simulation results are in good agreement with the design values and safety analysis results of HTR-PM.

Calculation and Analysis of Reinforced Concrete Continuous Box-Girder Overpass

2011 ◽  
Vol 101-102 ◽  
pp. 463-466
Author(s):  
Dong Yu Ji
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Simulation Analysis ◽  
Great Influence ◽  
Distribution Law ◽  
Box Girder ◽  
Common Structure ◽  
Element Simulation ◽  
Stress And Deformation ◽  
Calculation Software

Reinforced concrete continuous box-girder overpass is a common structure form, Wangzhuang overpass is example, this paper adopts universal finite element calculation software to carry out finite element simulation analysis for reinforced concrete continuous box-girder overpass. Considering the influence of overpass structure weight and driveway load, the distribution law of overpass stress and displacement were researched. Analysis results show that, load’s short-term effect combination has great influence on overpass structure, driveway slanting load’s influence on overpass structure’s stress and deformation can not be ignored.

Development of relocation model for debris particles in core disruptive accident analysis of sodium-cooled fast reactor

2020 ◽  
Vol 368 ◽  
pp. 110795
Author(s):  
Chunming Teng ◽  
Bin Zhang ◽  
Jianqiang Shan ◽  
Xisi Zhang ◽  
Yonggang Cao
Keyword(s):  
Fast Reactor ◽  
Accident Analysis ◽  
Debris Particles

scholarly journals Bandwidth Improvement in Bow-Tie Microstrip Antennas: The Effect of Substrate Type and Design Dimensions

2020 ◽  
Vol 10 (2) ◽  
pp. 504 ◽  
Author(s):  
Halgurd N. Awl ◽  
Yadgar I. Abdulkarim ◽  
Lianwen Deng ◽  
Mehmet Bakır ◽  
Fahmi F. Muhammadsharif ◽  
...  
Keyword(s):  
Simulation Analysis ◽  
Microstrip Antennas ◽  
Ultra Wideband ◽  
The Novel ◽  
Substrate Type ◽  
Antenna Performance ◽  
Uwb Applications ◽  
The Impact ◽  
Bow Tie ◽  
Good Agreement

In this work, the impact of substrate type and design dimensions on bow-tie microstrip antenna performance and bandwidth improvement is presented both numerically and experimentally at 4–8 GHz. The finite integration technique (FIT)-based high-frequency electromagnetic solver, CST Microwave Studio, was used for the simulation analysis. For this purpose, four bow-tie microstrip antennas were designed, fabricated, and measured upon using different materials and substrate thicknesses. Precise results were achieved and the simulated and experimental results showed a good agreement. The performance of each antenna was analyzed and the impact of changing material permittivity, antenna dimensions and substrate thicknesses on antenna performance were investigated and discussed. The measured results indicated that the slot bow-tie antenna, which is one of the novel aspects of this study, is well matched and a 2-GHz bandwidth [5–7 GHz] is obtained, which is about 50% bandwidth in comparison with the wideband applications [4–8 GHz]. The proposed structure is useful in ultra-wideband (UWB) applications. This study provides guidance in selecting material types and thicknesses for microstrip antennas based on desired applications.

scholarly journals Modelling shear strength of compacted soils

2019 ◽  
Vol 92 ◽  
pp. 15007
Author(s):  
Sam Bulolo ◽  
Eng Choon Leong
Keyword(s):  
Shear Strength ◽  
Unsaturated Soils ◽  
Soil Mechanics ◽  
Published Data ◽  
State Variables ◽  
Compacted Soils ◽  
Earth Structures ◽  
Unsaturated Soil Mechanics ◽  
Coulomb Failure Criterion ◽  
Direct Shear Apparatus

Compacted soils constitute most engineering projects such as earth dams, embankments, pavements, and engineered slopes because of their high shear strength and low compressibility. The shear strength of compacted soils is a key soil parameter in the design of earth structures but it is seldom determined correctly due to their unsaturated state. The shear strength of compacted soils can be better evaluated under the framework of unsaturated soil mechanics. Saturated and unsaturated tests were conducted on compacted specimens using conventional direct shear apparatus under constant water content condition. Tests were conducted at different water contents and net normal stresses. The main objective of this study is to develop a shear strength model for compacted soils. Initial matric suction was measured before the test using the filter paper method. The two-stress state variables together with the extended Mohr-Coulomb failure criterion for unsaturated soils were used to obtain a lower bound model of the shear strength. The model was demonstrated using published data.

scholarly journals Curie Temperature and Microstructural Changes Due to the Heating Treatment of Magnetic Amorphous Materials

2016 ◽  
Vol 61 (1) ◽  
pp. 451-456 ◽  
Author(s):  
J. Gondro ◽  
K. Błoch ◽  
P. Brągiel ◽  
M. Nabiałek ◽  
M. Szota
Keyword(s):  
Amorphous Materials ◽  
Elevated Temperatures ◽  
Great Influence ◽  
Soft Magnetic ◽  
Transmission Electron ◽  
Heisenberg Type ◽  
Heating Treatment ◽  
Magnetic Hardening ◽  
Curie Temperatures ◽  
Good Agreement

Three distinct alloys: Fe86Zr7Nb1Cu1B5, Fe82Zr7Nb2Cu1B8, and Fe81Pt5Zr7Nb1Cu1B5were characterized both magnetically and structurally. The samples, obtained with spinning roller method as a ribbons 3 mm in width and 20 μm thick, were investigated as-quenched and after each step of a multi steps heating treatment procedure. Each sample was annealed at four steps, fifteen minutes at every temperature, starting from 573K+600K up to +700K depending on type of alloy. Mössbauer spectroscopy data and transmission electron microscope (HRE M) pictures confirmed that the as-quenched samples are fully amorphous. This is not changed after the first stages of treatment heating leads to a reduction of free volumes. The heating treatment has a great influence on the magnetic susceptibilities. The treatment up to 600K improves soft magnetic properties: an χ increase was observed, from about 400 to almost 1000 for the samples of alloys without Pt, and from about 200 to 450 at maximum, for the Fe81Pt5Zr7Nb1Cu1B5. Further heating, at more elevated temperatures, leads to magnetic hardening of the samples. Curie temperatures, established from the location of Hopkinson’s maxima on the χ(T) curve are in very good agreement with those obtained from the data of specific magnetization, σ(T), measured in a field of 0.75T. As a critical parameter β was chosen to be equal 0.36 for these calculations, it confirmed that the alloys may be considered as ferromagnetic of Heisenberg type. Heating treatment resulted in decreasing of TC. These changes are within a range of several K.

Comparative study on the oily exudation of aluminized explosives containing EVA and F2603

2020 ◽  
Vol 19 (08) ◽  
pp. 2050035
Author(s):  
Jun Tao ◽  
Xiaofeng Wang ◽  
Kun Zhang
Keyword(s):  
Migration Rate ◽  
Polyvinyl Acetate ◽  
Vinylidene Fluoride ◽  
Great Influence ◽  
Binding Energies ◽  
The Other ◽  
Binding Strength ◽  
The Press ◽  
Exudation Rate ◽  
Good Agreement

In order to compare the influence of binders on the oily exudation of cyclotrimethylenetrinitramine (RDX) based aluminized explosives, polyvinyl acetate (EVA) and copolymer of vinylidene fluoride and perfluoropropylene (F2603) were selected as binders, which are most commonly used in the press-packed explosives. Herein, the binding energies of wax with the components of RDX-based aluminized explosives containing EVA and F2603 were predicted. Then, the migration models of wax in EVA and F2603 were constructed respectively, and the migration rate of wax in two binders was also calculated. Finally, experimental verification was carried out for wax migration in the two aluminized explosives. The results show that the binding energies of wax with other components of RDX-based composite explosive are all positive, which indicates that the physical compatibility of RDX-based aluminized explosives containing EVA and F2603 is excellent. In addition, wax interacts with the other components of RDX-based explosives mainly via Van der Waals force. However, the binding strength of wax with RDX crystals and binders decreases with the increase of temperature. The type of binders has a great influence on the migration rate of wax, and the oily exudation rate of wax in F2603 is about 4 times than that in EVA both at 298 K and 344 K. Meanwhile, the polymer configuration greatly changes the migration rate of wax. The calculated results are in good agreement with the experimental results.

The Research of the Relative Rigid Effect in the Numerical Simulation of the Steel Plate Reinforced Concrete Coupling Beams

2014 ◽  
Vol 638-640 ◽  
pp. 283-286
Author(s):  
Li Song ◽  
Dong Chen ◽  
Bao Lei Li
Keyword(s):  
Numerical Simulation ◽  
Reinforced Concrete ◽  
Steel Plate ◽  
Simulation Analysis ◽  
Great Influence ◽  
Shear Walls ◽  
Internal Force ◽  
Coupling Beams ◽  
Loading Mode ◽  
Deformation Properties

The coupling beam work as an important component in coupled shear walls, the strength,stiffness and deformation properties of which have great influence on the seismic performance of shear walls, the steel plate reinforced concrete coupling beams have the advantages as follows: simplify the constructional details, make the construction convenient and reliable performance [1][2]. The numerical simulation model in this paper is a coupled shear wall connected by steel plate reinforced concrete coupling beams in reference [3], and the loading mode is the same as the reference [4] . The relative stiffness effect was explored by study the internal force and displacement of the model with changing the stiffness of the coupling beams and the shear walls while the span-depth ratio is stable .The study will provide a reference for the numerical simulation of the finite element simulation analysis of the coupling beams and the steel reinforced concrete structures.

Modeling and Simulation of Gear Transmission System of Drive Axle with Romax

2011 ◽  
Vol 189-193 ◽  
pp. 2019-2024
Author(s):  
Zhen Nan Ye ◽  
Wen Ming Zhang ◽  
Yong Jiang ◽  
Zhi Jiang
Keyword(s):  
Fatigue Life ◽  
Simulation Analysis ◽  
Great Influence ◽  
Transmission System ◽  
Gear Transmission ◽  
Work Condition ◽  
Gear Transmission System ◽  
Articulated Vehicle ◽  
Drive Axle ◽  
Low Wear

Drive axle is a key part of transmission system on the articulated vehicle. Its stability has a great influence on the performance of the truck. The gear transmission system of 45t articulated vehicle drive axle is taken as an example while the virtual prototype models of drive axle gear transmission system are established with Romax. The comparative simulation analysis of fatigue life of drive axle supporting bearing is performed through two means, the ISO281 and Romax Adjusted, which are methods for predicting bearing fatigue life. The results of simulation show that each supporting bearing has long life, low wear rate and long working time; the prediction of bearing fatigue life with Romax Adjusted agree with the actual work condition of bearing.

Study on Dynamic Response Characteristics of Composite Thin-Walled Square Beam Subject to Three-Point Bending

2012 ◽  
Vol 201-202 ◽  
pp. 715-720
Author(s):  
Gang Yi Zhou ◽  
Xin Long Dong ◽  
Jun Liu
Keyword(s):  
Composite Beam ◽  
Simulation Analysis ◽  
Impact Load ◽  
Single Beam ◽  
Three Point Bending ◽  
Response Characteristics ◽  
Crushing Force ◽  
Good Energy ◽  
Thin Walled ◽  
Good Agreement

In this paper, the experiment of thin-walled square beam subject to three-point bending by using the self-devised drop-hammer impact was carried out. The mechanical behavior of this thin-walled specimen under impact load was obtained. The process of deformation and the dynamic buckling behaviors of composite square beam were analyzed by mean of simulation technique of finite element using ANSYS/LS-DYNA. The simulation analysis of deformation and crushing force characteristics was in good agreement with the experimental results. Meanwhile, the comparative analysis of percussive force and energy absorbability from composite beam and single beam was performed. It is shown by the investigation that the peak percussive force of such composite beam falls down relative to single beam and it possesses good energy absorbability too. The computed result also shows reducing the thickness of the bottom board of such thin-walled square beam has less of an effect on the energy absorbability.

Sign in / Sign up

Export Citation Format

Share Document