Experimental study of submerged gas jets in liquid cross flow

Abstract

Gas jets submerged in the liquid cross flow are prevalent in the nature and essential in numerous industrial applications. The interaction between the gas jet and liquid cross flow is not well characterized for the difficulties in experimental research. In the present work, a new experimental method was designed and the evolution of the gas jet in liquid cross flow was captured by the high speed camera. Five experimental cases with different initial liquid cross flow velocities (0.35 m/s, 0.7 m/s, 1.0 m/s, 1.5 m/s, 2.0 m/s) were performed where the momentum ratio of the initial gas jet to liquid cross flow varies to highlight the effects of the liquid cross flow velocity on the flow characteristics. The summation and statistical methods were adopted to analyze the experimental sequences, and the results from the two methods showed good agreement. The gas jet morphology and the gas liquid interface were clearly identified from the experimental results, which showed that the gas jet deflected in a less pronounced manner with less unsteadiness generated at the gas liquid interface as the liquid cross flow velocity decreases. The gas jet penetration length in the momentum region was measured and it was found to be severely influenced by the liquid cross flow, and a power relationship was found between the gas jet penetration length and the cross flow velocity. The expansion angle of the gas jet in the upstream was also shown to grow in a power function with the liquid cross flow velocity. The gas jet diameter indicates the ambient liquid entrainments and the gas liquid interface evolution. In the region where the gas jet momentum is dominant, the evolution of the gas jet diameter followed a similar pattern with the submerged gas jets without liquid cross flow. Finally, empirical correlations were developed to predict the characteristic parameters of the submerged gas jet in liquid cross flow.