バスタブ渦による気泡巻込み量のモデル化

抄録

In the design study on sodium-cooled fast reactors, .it is important to investigate the gas entrainment (GE) phenomena in detail. In fact, a lot of analytical, experimental and numerical studies have been conducted to clarify the onset condition of GE and some GE onset models have been proposed. However, few studies on the modeling of entrained gas flow rate has been conducted due to the difficulty on modeling the gas bubble entrainment at a free surface, which is accompanied by complicated free surface deformation. In this paper, the authors propose a mechanistic model to predict the entrained gas flow rate by a free surface vortex. The model contains the theoretical equation of transient gas core elongation and the empirical equation of critical gas core length for gas bubble detachment. The mechanistic model is applied to predict the entrained gas flow rate in a simple GE experiment. As a result, the predicted results show qualitatively good agreement with the experimental results of the entrained gas flow rate. Therefore, it is confirmed that the proposed mechanistic model can predict the entrained gas flow rate by a free surface vortex.