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Ono, Jun; Mori, Takero; Sotsu, Masutake; Ohira, Hiroaki
Proceedings of ASME 2013 International Mechanical Engineering Congress and Exposition (IMECE 2013) (DVD-ROM), 9 Pages, 2013/11
The severe accident evaluation on the EVST of MONJU has ever been performed by one-dimensional flow network code "Super-COPD". However, it is difficult to predict thermal-hydraulics in the EVST accurately because the fluid in the EVST is driven by natural circulation. Thus we have performed multidimensional thermal-hydraulic analysis in order to clarify the thermal-hydraulic behavior and evaluate the appropriateness of the flow network model. As a result, it was noted that the multidimensionality on temperature and velocity in the EVST was small enough and the flow network model would be almost appropriate. It should be noted that flow resistance of the supporting plates or the heat transfer center of the cooling coils should be set conservatively for the safety analysis.
Koizumi, Yasuo*; Nago, Kohei*; Uchibori, Akihiro; Kamide, Hideki; Ohshima, Hiroyuki
Proceedings of ASME 2013 International Mechanical Engineering Congress and Exposition (IMECE 2013) (DVD-ROM), 6 Pages, 2013/11
Flow visualization experiments of an air jet in liquid were performed. The air jet was blown vertically upward into stagnant water or kerosine in the test vessel from a 1 mm width nozzle which was located at the bottom of the test vessel. A flow state of the jet in the liquid was recorded with a high speed video camera. Experimental result showed that the filament-like ears and wisps were pulled out from the wavy interface between liquid and the air jet. The ears and wisps were broken off and entrained into the air jet. As the air jet velocity increased, the number of entrainments created by the air jet increased lineally. The correlation for the entrainment diameter distribution which was developed for the annular dispersed two-phase flow in a pipe predicted well the present results. Measured entrainment rates were considerably lower than the prediction of the correlation for the annular dispersed two-phase flow in a pipe.
