A method for predicting the breakup of gas column in a decaying swirling liquid field

In the fission gas system design scheme for molten salt reactors, the bubbles carrying the fission gas converge to the center of the pipe to form a column of gas under a swirling flow field. The system separates the fission gas by removing the gas column. During the separation process, an important question is how to judge the stability of the gas column, since the breakup of gas column may greatly affect the separation efficiency. In this paper, the linear instability analysis and the swirling decay model have been combined to develop a new model for estimating the breakup location of a gas column. To validate this method, a two-phase swirling flow experiment has been conducted. The correlations of interfacial wavenumber and gas column's radius required in the theoretical model are obtained from experimental data. The predicted breakup locations and measured breakup locations are compared. The results show that the prediction error of the interfacial wave number and the gas column is within 20% and the error of the breakup position prediction method is within 30%.