An Atomistic-to-Microscale Computational Analysis of the Dislocation Pileup-induced Local Stresses near an Interface in Plastically Deformed Two-phase Materials

2022 ◽  
pp. 117663
Author(s):  
Yipeng Peng ◽  
Rigelesaiyin Ji ◽  
Thanh Phan ◽  
Wei Gao ◽  
Valery I. Levitas ◽  
...  
Keyword(s):  
Computational Analysis ◽  
Dislocation Pileup ◽  
Two Phase ◽  
Local Stresses

Two-Phase Flow Behavior in Channels With Sudden Area Change Using Experimental and Computational Approach

2017 ◽  
Author(s):  
Ashish Kotwal ◽  
Che-Hao Yang ◽  
Clement Tang
Keyword(s):  
Experimental Data ◽  
Pressure Drop ◽  
Experimental Analysis ◽  
Single Phase ◽  
Computational Analysis ◽  
Phase Flow ◽  
Single Phase Flow ◽  
Two Phase ◽  
Flow Rates ◽  
Area Change

The current study shows computational and experimental analysis of multiphase flows (gas-liquid two-phase flow) in channels with sudden area change. Four test sections used for sudden contraction and expansion of area in experiments and computational analysis. These are 0.5–0.375, 0.5–0.315, 0.5–0.19, 0.5–0.14, inversely true for expansion channels. Liquid Flow rates ranging from 0.005 kg/s to 0.03 kg/s employed, while gas flow rates ranging from 0.00049 kg/s to 0.029 kg/s implemented. First, single-phase flow consists of only water, and second two-phase Nitrogen-Water mixture flow analyzed experimentally and computationally. For Single-phase flow, two mathematical models used for comparison: the two transport equations k-epsilon turbulence model (K-Epsilon), and the five transport equations Reynolds stress turbulence interaction model (RSM). A Eulerian-Eulerian multiphase approach and the RSM mathematical model developed for two-phase gas-liquid flows based on current experimental data. As area changes, the pressure drop observed, which is directly proportional to the Reynolds number. The computational analysis can show precise prediction and a good agreement with experimental data when area ratio and pressure differences are smaller for laminar and turbulent flows in circular geometries. During two-phase flows, the pressure drop generated shows reasonable dependence on void fraction parameter, regardless of numerical analysis and experimental analysis.

A Method of Limiting Intermediate Values of Volume Fraction in Iterative Two-Fluid Computations

1982 ◽  
Vol 24 (4) ◽  
pp. 221-224 ◽  
Author(s):  
M. B. Carver
Keyword(s):  
Fluid Flow ◽  
Computational Analysis ◽  
Volume Fraction ◽  
Simultaneous Solution ◽  
Two Phase ◽  
Upper Limit ◽  
Satisfactory Method ◽  
Iterative Procedures ◽  
Physical Reasons ◽  
Two Fluid

Multidimensional computational analysis of fluid flow is usually done by segmented iterative methods, as the equations sets generated are too large to permit simultaneous solution. Frequently the need arises to compute values for variables which must remain bounded for physical reasons. In two-phase computation, for example, the volume fraction is restricted to values between 0 and 1, but iterative procedures often return intermediate values which violate these bounds. It is fairly straightforward to prevent negative values, however no satisfactory method of imposing the upper limit has been published. A method of smoothly applying the limit in reversible fashion is outlined in this note.

scholarly journals A Roadmap for Computational Communication Research

2019 ◽  
Vol 1 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Wouter van Atteveldt ◽  
Drew Margolin ◽  
Cuihua Shen ◽  
Damian Trilling ◽  
René Weber
Keyword(s):  
Computational Analysis ◽  
Review Process ◽  
Open Access Journal ◽  
Theoretical Development ◽  
Communication Research ◽  
Two Phase ◽  
Double Blind ◽  
Blind Review ◽  
Working Paper ◽  
Computational Research

Abstract Computational Communication Research (CCR) is a new open access journal dedicated to publishing high quality computational research in communication science. This editorial introduction describes the role that we envision for the journal. First, we explain what computational communication science is and why a new journal is needed for this subfield. Then, we elaborate on the type of research this journal seeks to publish, and stress the need for transparent and reproducible science. The relation between theoretical development and computational analysis is discussed, and we argue for the value of null-findings and risky research in additive science. Subsequently, the (experimental) two-phase review process is described. In this process, after the first double-blind review phase, an editor can signal that they intend to publish the article conditional on satisfactory revisions. This starts the second review phase, in which authors and reviewers are no longer required to be anonymous and the authors are encouraged to publish a preprint to their article which will be linked as working paper from the journal. Finally, we introduce the four articles that, together with this Introduction, form the inaugural issue.

Computational Analysis of Downcomer Boiling Phenomena Using a Component Thermal Hydraulic Analysis Code, CUPID

2010 ◽  
Vol 133 (5) ◽  
Author(s):  
Hyoung Kyu Cho ◽  
Byong Jo Yun ◽  
Ik Kyu Park ◽  
Jae Jun Jeong
Keyword(s):  
Computational Analysis ◽  
Nuclear Reactor ◽  
Three Dimensional ◽  
Reactor Vessel ◽  
Physical Models ◽  
Low Flow ◽  
Two Phase ◽  
Rate Condition ◽  
Flow Models ◽  
Loss Of Coolant Accident

For the analysis of transient two-phase flows in nuclear reactor components such as a reactor vessel, a steam generator, and a containment, KAERI has developed a three-dimensional thermal hydraulic code, CUPID. It adopts a three-dimensional, transient, two-phase and three-field model and includes various physical models and correlations of the interfacial mass, momentum, and energy transfer for the closure. In the present paper, the CUPID code and its two-phase flow models were assessed against the downcomer boiling experiment, which was performed to simulate the downcomer boiling phenomena. They may happen in the downcomer of a nuclear reactor vessel during the reflood phase of a postulated loss of coolant accident. The stored energy release from the reactor vessel to the liquid inside the downcomer causes the boiling on the wall, and it can reduce the hydraulic head of the accumulated water, which is the driving force of water reflooding to the core. The computational analysis using the CUPID code showed that it can appropriately predict the multidimensional boiling phenomena under a low pressure and low flow rate condition with modification of the bubble size model.

scholarly journals Computational analysis of the near-Earth magnetospheric current system during two-phase decay storms

2001 ◽  
Vol 106 (A12) ◽  
pp. 29531-29542 ◽  
Author(s):  
M. W. Liemohn ◽  
J. U. Kozyra ◽  
C. R. Clauer ◽  
A. J. Ridley
Keyword(s):  
Computational Analysis ◽  
Current System ◽  
Two Phase ◽  
Magnetospheric Current System
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