Transient Behavior of Gas Entrainment Caused by Surface Vortex

• Published in: Heat transfer engineering Vol. 29; no. 8; pp. 659 - 666
• Main Authors: Ezure, Toshiki, Kimura, Nobuyuki, Hayashi, Kenji, Kamide, Hideki
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA Taylor & Francis Group 01.08.2008; Taylor & Francis
• Subjects: Applied sciences; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fission nuclear power plants; Installations for energy generation and conversion: thermal and electrical energy; Dimensioning; Liquid metal cooled reactors; Sodium; Fast breeder; Entrainment; Particle image velocimetry; Reactor core; Nuclear reactor
• ISSN: 0145-7632; 1521-0537
• DOI: 10.1080/01457630801980574

A compact sodium-cooled reactor is an important candidate as a fast breeder reactor (FBR) and has been investigated in the feasibility study of FBR cycle. Due to the compact sizing of the reactor vessel, gas entrainment at the free surface of sodium coolant becomes one of the significant issues for reactor design, and it is required to clarify the criterion of gas entrainment at free surface and the tolerance. In the present study, some visualization experiments were performed in a water-air system focusing on the gas entrainment due to surface vortex and its transient phenomena. Influences of horizontal velocity were clarified by the visualization. The gas entrainment due to the surface vortex occurs intermittently. Time trends of circulation and length of gas core for the intermittent surface vortices were measured by the particle image velocimetry and visualization. It was found that the gas core length extends with time delay to the increase of circulation around the vortex.