Development of prediction technology of two-phase flow dynamics under earthquake acceleration, 10; Numerical prediction of velocity profile around bubble under accelerating condition

Yoshida, Hiroyuki  ; Nagatake, Taku ; Takase, Kazuyuki; Kaneko, Akiko*; Monji, Hideaki*; Abe, Yutaka*

Behavior of gas-liquid two-phase flow in nuclear reactors is unknown under the earthquake conditions. Therefore, the behavior of two-phase flow is investigated in a series of study. In this study, to develop the predictive technology of two-phase flow dynamics under earthquake acceleration, a detailed two-phase flow simulation code with an advanced interface tracking method, TPFIT, was expanded. In this paper, the bubbly flow in a horizontal pipe excited by oscillation acceleration and under the fluctuation of the liquid flow was simulated by using the expanded TPFIT. Predicted time series data of velocity profiles around the bubbles and shapes of bubbles were compared with measured results under flow rate fluctuation and structural vibration. Predicted results were in good agreement with measured results qualitatively. Moreover it was concluded that the expanded TPFIT can be applied to qualitative analysis of bubbly flow under accelerating conditions.