过冷水中蒸汽射流自旋凝结的实验研究

To show the complex flow and phasc changc in thc condensation of swirling steam jet, an experimental study was condueted in this paper. Firstly, a novel X-type swirl pressure nozzlc was employcd to achieve thc swirling flow of the steam jet. Ncxt, thc condensation regimes of swirling bubblcs and the evolution of related parameters were analyzed at various mass flow rates, and these parameters included bubblc radius, growth rate, collapsc rate, maximum migration speed of the bubble center, and collapse frequency. Thc results show that there were three condensation regimes: smooth grown bubblc regime, transition regime, and rough grown bubblc regime. Under the influence of centrifugal force, typical bchaviors such as neck torsion and irregulär deformation of the jet bulge at the top of bubbles may oeeur during the condensation process. As the mass flow rate increased, the bubble condensation time decreased, the growth rate increased, and both bubblc radius and collapse rate exhibited nonlincar changes. Thc maximum migration speed of the bubblc center ranged from 24. 3 m/s to 73. 23 m/s, while the bubblc collapse frequency varied between 20 Hz and 302 Hz. At the same mass flow rate, bubblcs may condense in different directions and display a zigzag motion trajeetory. An increasing in the deviation angle of the bubble center relative to the central axis of the nozzle helps reduce the rebound number during the collapse, exerting a nonlinear impact on the bubblc growth rate, collapse rate, and maximum migration speed of the bubblc center. This study can provide a theoretical support to some extent for the development and optimization of condensation technologies in related industrial ficlds.