Microscopic film collapse behavior at trigger for vapor explosion

2002 ◽  
Author(s):  
Yutaka Abe ◽  
Hideki Nariai
Keyword(s):  
Vapor Explosion ◽  
Collapse Behavior ◽  
Film Collapse

Visual Observation of Vapor Film Collapse Behavior During Vapor Explosion

2002 ◽  
Author(s):  
Yutaka Abe ◽  
Hideki Nariai
Keyword(s):  
High Temperature ◽  
Pressure Pulse ◽  
Film Surface ◽  
Vapor Film ◽  
Visual Data ◽  
Vapor Explosion ◽  
Auto Correlation ◽  
Piv Technique ◽  
Collapse Behavior ◽  
Film Collapse

During severe accident of a light water reactor, various thermal hydraulic phenomena including vapor explosion could threaten the integrity of the containment vessel. Thermal detonation model is proposed to describe the vapor explosion. According to the model, several processes should be sequentially satisfied for the trigger phenomena of the vapor explosion. One of the most important processes for the trigger phenomena is the vapor film collapse around high temperature molten material droplets. In the present study, the vapor film collapse behavior around high temperature solid particle submerged into water was experimentally investigated by attacking a pressure pulse to the vapor film on a high temperature sold particle. The interfacial phenomena between vapor and water were measure by using a high-speed video camera of the maximum speed of 40,500 fps. The visual data obtained were processed with visual data processing techniques. That is, the average vapor film thickness was estimated, dynamic behaviors of the interfaces were analyzed with PIV technique and the interface movement was estimated with the digital auto correlation techniques from the visual data obtained. Furthermore, the transients of the temperature and pressure were simultaneously measured. The interfacial temperatures between vapor and water, and between molted liquid and water are analytically estimated by solving the heat conduction equation with the data obtained as the boundary conditions. It is clarified that vapor collapse by pressure pulse occurs homogeneously around the vapor film surface on a high temperature particle. Microscopic information are obtained from the visual data by using visual data processing technique, PIV technique and digital auto-correlation technique. At the time the vapor film surface changes to white, the saturation temperature exceeds the interfacial temperature. The microscopic vapor film collapse behavior indicates the possibility of the phase change at the vapor film collapse.

B212 Microscopic film collapse behavior at trigger process for vapor explosion.

2001 ◽  
Vol 2001 (0) ◽  
pp. 403-404
Author(s):  
Yutaka ABE ◽  
HIROSHI Yanagida ◽  
Yukihiro HAMADA ◽  
Hideki NARIAI
Keyword(s):  
Vapor Explosion ◽  
Collapse Behavior ◽  
Film Collapse

scholarly journals Visual Observation of Microscopic film collapse behavior at vapor explosion

2002 ◽  
Vol 2002.8 (0) ◽  
pp. 413-414
Author(s):  
Yutaka ABE ◽  
HIROSHI Yanagida ◽  
Koji OKAMOTO ◽  
Hideki NARIAI
Keyword(s):  
Visual Observation ◽  
Vapor Explosion ◽  
Collapse Behavior ◽  
Film Collapse

scholarly journals Study of Film Collapse Behavior during Vapor Explosion.

1999 ◽  
Vol 65 (636) ◽  
pp. 2799-2805 ◽  
Author(s):  
Masahiro YAGI ◽  
Yutaka ABE ◽  
Hiromichi ADACHI ◽  
Jun SUGIMOTO ◽  
Norihiro YAMANO
Keyword(s):  
Vapor Explosion ◽  
Collapse Behavior ◽  
Film Collapse

NUMERICAL SIMULATION OF THE VAPOR FILM COLLAPSE BEHAVIOR AT VAPOR EXPLOSION WITH THREE-DIMENSIONAL LATTICE GAS THERMAL-HYDRAULIC AUTOMATA METHOD

2003 ◽  
Vol 17 (01n02) ◽  
pp. 189-192
Author(s):  
DAISUKE TOCHIO ◽  
YUTAKA ABE ◽  
YOSUKE MATSUKUMA ◽  
HIDEKI NARIAI
Keyword(s):  
Numerical Simulation ◽  
Phase Change ◽  
Lattice Gas ◽  
Three Dimensional ◽  
Experimental Result ◽  
Vapor Film ◽  
Lattice Gas Automata ◽  
Numerical Result ◽  
Collapse Behavior ◽  
Film Collapse

In order to clarify the dominant driving force of complex vapor film collapse behavior, numerical simulation is performed with three-dimensional fifteen-velocity lattice gas automata method. As the result, numerical result is qualitatively different from the experimental result. On the other hand, numerical simulation of vapor film collapse behavior is performed with three-dimensional fifteen-velocity lattice gas automata method including phase-change effect. As the result, numerical result is qualitatively similar to the experimental results. Comparison between the experimental result and the numerical result confirms that experimentally observed vapor film collapse behavior is dominated not by fluid motion but by phase change.

Vapor Film Collapse Behavior during Quenching of Small Platinum Sphere into Polymer Aqueous Solution

2020 ◽  
Vol 2020.69 (0) ◽  
pp. 605
Author(s):  
SHIMAOKA Mitsuyoshi ◽  
YOSHIDA Hiroshi ◽  
IKUTA Fumiaki ◽  
IKEDA Nobuhiro ◽  
NAKAMURA Shigeto
Keyword(s):  
Aqueous Solution ◽  
Vapor Film ◽  
Collapse Behavior ◽  
Film Collapse ◽  
Polymer Aqueous Solution
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