scholarly journals An Equivalent Multi-Phase Similitude Law for Pseudodynamic Test on Small-scale RC Models : Verification Tests

2004 ◽  
Vol 8 (5) ◽  
pp. 35-43
Keyword(s):  
Small Scale ◽  
Pseudodynamic Test ◽  
Multi Phase

Analysis of a Large Scale Liquid Hydrogen Dispersion Using the Multi-Phase Hydrodynamics Analysis Code (CHAMPAGNE)

2002 ◽  
Vol 124 (4) ◽  
pp. 283-289 ◽  
Author(s):  
K. Chitose ◽  
M. Okamoto ◽  
K. Takeno ◽  
K. Hayashi ◽  
M. Hishida
Keyword(s):  
Large Scale ◽  
Clean Energy ◽  
Liquid Hydrogen ◽  
Calculation Model ◽  
Small Scale ◽  
Simulation Code ◽  
Large Tank ◽  
Basic Functions ◽  
Multi Phase ◽  
And Storage

It is planned to use hydrogen extensively as a source of clean energy in the new century. As part of our investigation for an International Clean Energy Network Using Hydrogen Conversion (WE-NET), we have been studying to establish a safety scheme to ensure that both existing and new hydrogen technologies are implemented without endangering public safety. In this plan, we consider the transport and storage of a large quantity of hydrogen in a large tank. First we must evaluate the consequence of the postulated accident of liquid hydrogen. Since we have developed the multi-phase hydrodynamics analysis code (CHAMPAGNE), we apply the code to simulate the formation and dispersion of hydrogen vapor clouds. In the present paper we have improved the calculation model in two ways. We added a function to CHAMPAGNE for solving evaporation phenomena realistically, made many parametric calculations and planned the small-scale hydrogen dispersion experiments for the validation of this model. Another improvement is the turbulent mixing of evaporated liquid hydrogen. Now we have completed the basic functions of our simulation code. And these models of CHAMPANGE code must be verified by the experimental data.

scholarly journals TOWARD UNDERSTANDING THE ORIGIN OF TURBULENCE IN MOLECULAR CLOUDS: SMALL-SCALE STRUCTURES AS UNITS OF DYNAMICAL MULTI-PHASE INTERSTELLAR MEDIUM

2012 ◽  
Vol 754 (2) ◽  
pp. 95 ◽  
Author(s):  
Kengo Tachihara ◽  
Kazuya Saigo ◽  
Aya E. Higuchi ◽  
Tsuyohshi Inoue ◽  
Shu-ichiro Inutsuka ◽  
...  
Keyword(s):  
Interstellar Medium ◽  
Molecular Clouds ◽  
Small Scale ◽  
Scale Structures ◽  
Multi Phase ◽  
Small Scale Structures

A Combined Experimental and Computational Study for the Design of a Low Water Consumption Cooling Tower

2014 ◽  
Author(s):  
Burak Dogan ◽  
Ibrahim Yilmaz ◽  
Ozgur Polat ◽  
Oytun Karabulut ◽  
Ahmet Ural ◽  
...  
Keyword(s):  
Water Consumption ◽  
Cooling Tower ◽  
Computational Study ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Small Scale ◽  
Computational Fluid Dynamics Cfd ◽  
Set Up ◽  
Multi Phase ◽  
Alternative Designs

In this study, a combined experimental and computational study for the design of a low water consumption cooling tower is performed. The purpose of the study is to reduce the water consumption without decreasing the efficiency of a typical cooling tower. To achieve this aim, it is necessary to enhance the homogeneity of mist/air mixture. For this purpose, firstly, an experimental set-up including a small scale wind tunnel is installed which provides opportunity to examine different inlet and outlet configurations easily. Computational Fluid Dynamics (CFD) is used extensively to examine the effects of different configurations before experimental studies. Simulations of different inlet and outlet configurations are performed using only air. Several turbulators are designed and simulated to increase the turbulence levels. A three dimensional multi-phase CFD model is utilized to design a nozzle-turbulator system for the cooling tower. As results of the computational and experimental studies, the most efficient inlet and outlet configurations are specified and turbulators are selected from the alternative designs.

On the Effect of Narrow and Long Corrosion Defects on the Collapse Pressure of Pipelines

2007 ◽  
Author(s):  
T. A. Netto
Keyword(s):  
Numerical Models ◽  
Simple Procedure ◽  
Small Scale ◽  
Offshore Pipelines ◽  
Internal Corrosion ◽  
Chemical Contaminants ◽  
Collapse Pressure ◽  
Multi Phase Flow ◽  
Corrosion Defects ◽  
Multi Phase

Internal corrosion in pipelines is often caused by water, sediment, or chemical contaminants present in the multi-phase flow. This normally occurs at the bottom of the pipe and at low points in the pipeline where sediment and water can settle out of the product being transported, therefore creating narrow and long defects. The effect of corrosion defects on the collapse pressure of offshore pipelines was studied through combined small-scale experiments and nonlinear numerical analyses based on the finite element method. After calibrated in view of the experimental results, the model was used to determine the collapse pressure as a function of material and geometric parameters of different pipes and defects. An extensive parametric study using 2-D and 3-D numerical models was carried out encompassing different defect geometries and their interaction with pipe ovalization. This paper reports these results which are subsequently used to develop a simple procedure for estimating the collapse pressure of pipes with narrow defects.

Analysis of a Large Scale Liquid Hydrogen Dispersion Using the Multi-Phase Hydrodynamics Analysis Code (CHAMPAGNE)

1999 ◽  
Author(s):  
K. Chitose ◽  
K. Takeno ◽  
M. Okamoto ◽  
K. Hayashi ◽  
M. Hishida
Keyword(s):  
Large Scale ◽  
Clean Energy ◽  
Liquid Hydrogen ◽  
Calculation Model ◽  
Small Scale ◽  
Simulation Code ◽  
Large Tank ◽  
Basic Functions ◽  
Multi Phase ◽  
And Storage

Abstract It is planned to use hydrogen extensively as a source of clean energy in the next century. As part of our investigation for an International Clean Energy Network Using Hydrogen Conversion (WE-NET), we have been studying to establish a safety scheme to ensure that both existing and new hydrogen technologies are implemented without endangering public safety. In this plan, we consider the transport and storage of a large quantity of hydrogen in a large tank. First we must evaluate the consequence of the postulated accident of liquid hydrogen. Since we have developed the multi-phase hydrodynamics analysis code (CHAMPAGNE), we apply the code to simulate the formation and dispersion of hydrogen vapor clouds. In the present paper we have improved the calculation model in two ways. We added a function to CHAMPANGE for solving evaporation phenomena realistically, made many parametric calculations and planned the small-scale hydrogen dispersion experiments for the validation of this model. Another improvement is the turbulent mixing of evaporated liquid hydrogen. Now we have completed the basic functions of our simulation code. And these models of CHAMPANGE code must be verified by the experimental data.

Reasons to strike first

2019 ◽  
Vol 42 ◽  
Author(s):  
William Buckner ◽  
Luke Glowacki
Keyword(s):  
Intergroup Conflict ◽  
Small Scale

Abstract De Dreu and Gross predict that attackers will have more difficulty winning conflicts than defenders. As their analysis is presumed to capture the dynamics of decentralized conflict, we consider how their framework compares with ethnographic evidence from small-scale societies, as well as chimpanzee patterns of intergroup conflict. In these contexts, attackers have significantly more success in conflict than predicted by De Dreu and Gross's model. We discuss the possible reasons for this disparity.

Exploring Coronal Structures with SOHO

2000 ◽  
Vol 179 ◽  
pp. 403-406
Author(s):  
M. Karovska ◽  
B. Wood ◽  
J. Chen ◽  
J. Cook ◽  
R. Howard
Keyword(s):  
Solar Corona ◽  
Image Enhancement ◽  
Coronal Mass Ejections ◽  
Dynamical Evolution ◽  
Small Scale ◽  
Low Contrast ◽  
Contrast Structures ◽  
Scale Structures ◽  
Small Scale Structures ◽  
Coronal Structures

AbstractWe applied advanced image enhancement techniques to explore in detail the characteristics of the small-scale structures and/or the low contrast structures in several Coronal Mass Ejections (CMEs) observed by SOHO. We highlight here the results from our studies of the morphology and dynamical evolution of CME structures in the solar corona using two instruments on board SOHO: LASCO and EIT.

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