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Ito, Kei; Ezure, Toshiki; Ohshima, Hiroyuki; Kawamura, Takumi*; Nakamine, Yoshiaki*
Proceedings of 9th Korea-Japan Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-9) (CD-ROM), 6 Pages, 2014/11
The authors have been studied the vortex cavitation in sodium-cooled fast reactors. In this paper, the authors present a modified evaluation method for vortex cavitation, in which a surface tension is modeled mechanistically. Namely, the cavity radius is calculated in consideration of radial pressure distribution, saturated vapor pressure and the pressure jump condition at an interface. As the basic validation of the developed surface tension model, numerical analyses of a simple experiment under various velocity conditions are performed. The evaluation results give qualitatively appropriate tendency, that is, the cavity radius becomes larger with the higher liquid velocity and/or lower reference pressure which cause the larger pressure drop at the vortex. In addition, the authors evaluate the influence of the kinematic viscosity which plays an important role in the vortex cavitation occurrences in the experiments.
Ito, Kei; Ezure, Toshiki; Ohshima, Hiroyuki; Kawamura, Takumi*; Nakamine, Yoshiaki*
no journal, ,
The prevention of vortex cavitation is one of key factors in the safety design criteria for sodium-cooled fast reactors. Therefore, the authors have developed a CFD-based evaluation method to determine the occurrence of the vortex cavitation. In this paper, the accuracy of the evaluation method is enhanced by developing a surface tension model by which the cavity radius is calculated in consideration of radial pressure distribution, saturated vapor pressure and the pressure jump condition at an interface. As a basic validation of the developed surface tension model, numerical analyses of a simple experiment under various velocity and pressure conditions are performed. The evaluation results give qualitatively appropriate cavity radius which becomes larger with the higher liquid velocity and/or lower reference pressure. Therefore, the developed surface tension model is considered to be physically-appropriate.