Group Title: 7th International Conference on Multiphase Flow - ICMF 2010 Proceedings
Title: P2.32 - Molten Oxidic Particle Fracture during Quenching in Water
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Permanent Link: http://ufdc.ufl.edu/UF00102023/00486
 Material Information
Title: P2.32 - Molten Oxidic Particle Fracture during Quenching in Water Multiphase Flows with Heat and Mass Transfer
Series Title: 7th International Conference on Multiphase Flow - ICMF 2010 Proceedings
Physical Description: Conference Papers
Creator: Kudinov, P.
Kudinova, V.
Dinh, T.-N.
Publisher: International Conference on Multiphase Flow (ICMF)
Publication Date: June 4, 2010
 Subjects
Subject: oxidic melt
fragmentation
quenching
transient boiling
thermal-stress
fracture
debris formation
 Notes
Abstract: Present work is motivated by the observations of debris particles morphology obtained as a result of quenching of high temperature molten oxidic jet in a subcooled water pool. Insights gained from the Debris Bed Formation (DEFOR) experiments (Kudinov et al., 2010) paved way to suggestions that melt fragmentation and the resulting particle morphology are largely influenced by (i) melt droplet instability and breakup; (ii) melt cooling and solidification; (iii) cavity formation; and (iv) solid particle fracture. Analysis of the DEFOR results suggests that there is a strong influence of water subcooling on the debris morphology. Particles are round-shape if subcooling of water is less than 50°C, and, at subcooling higher than 80°C, most of the particles are fractured rock-like with sharp edges. In present work we are considering the following hypothesis which can explain an apparent strong influence of moderate changes in temperature of water on morphology of the debris particle: rapid increase of heat flux during transition from film to nucleate boiling can cause solid particle fracture due to thermal stress. To verify the hypothesis we perform transient heat transfer and thermo-elastic stress analysis for a melt droplet instantaneously immersed into water coolant. We are also examining competition between hydrodynamic fragmentation and freezing at transient boiling heat transfer to identify conditions at which characteristic time scales are competitive. In the paper we demonstrate that rapid change in transient boiling heat flux (which is highly sensitive to water subcooling) can cause fracture of the particle. As well there is an effect of competition between freezing and hydrodynamic fragmentation at high subcooling of water. By parametric study we develop a “map” of the debris morphology. The map defines whether or not the particle will be fractured taking into account intrinsic uncertainty in the transition boiling characteristics and particle material properties. The map appears to be in a good agreement with the experimental observations (Kudinov et al., 2010).
General Note: The International Conference on Multiphase Flow (ICMF) first was held in Tsukuba, Japan in 1991 and the second ICMF took place in Kyoto, Japan in 1995. During this conference, it was decided to establish an International Governing Board which oversees the major aspects of the conference and makes decisions about future conference locations. Due to the great importance of the field, it was furthermore decided to hold the conference every three years successively in Asia including Australia, Europe including Africa, Russia and the Near East and America. Hence, ICMF 1998 was held in Lyon, France, ICMF 2001 in New Orleans, USA, ICMF 2004 in Yokohama, Japan, and ICMF 2007 in Leipzig, Germany. ICMF-2010 is devoted to all aspects of Multiphase Flow. Researchers from all over the world gathered in order to introduce their recent advances in the field and thereby promote the exchange of new ideas, results and techniques. The conference is a key event in Multiphase Flow and supports the advancement of science in this very important field. The major research topics relevant for the conference are as follows: Bio-Fluid Dynamics; Boiling; Bubbly Flows; Cavitation; Colloidal and Suspension Dynamics; Collision, Agglomeration and Breakup; Computational Techniques for Multiphase Flows; Droplet Flows; Environmental and Geophysical Flows; Experimental Methods for Multiphase Flows; Fluidized and Circulating Fluidized Beds; Fluid Structure Interactions; Granular Media; Industrial Applications; Instabilities; Interfacial Flows; Micro and Nano-Scale Multiphase Flows; Microgravity in Two-Phase Flow; Multiphase Flows with Heat and Mass Transfer; Non-Newtonian Multiphase Flows; Particle-Laden Flows; Particle, Bubble and Drop Dynamics; Reactive Multiphase Flows
 Record Information
Bibliographic ID: UF00102023
Volume ID: VID00486
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: P232-Kudinov-ICMF2010.pdf

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