Twisted tape has been widely used in industry and heat transfer enhancement. However, most research is focused on the single-phase flow induced by the tape; the flow characteristics in the gas-liquid two-phase flow induced by the tape are largely unexplored. In this work, vortex motion and decay characteristics in a gas-liquid two-phase swirl flow induced by a short twisted tape were studied by numerical simulation, and two parameters used to quantitatively describe the decay in a two-phase swirl flow have been proposed. Calculated results show that two corotating helical vortices appear and remain in the swirling flow, and these vortices significantly influence liquid distribution. Two peaks of liquid film thickness appear in the circumferential direction, and the liquid film gradually becomes uniform along the streamwise direction. Low pressure core locates near the region with thick liquid film instead of the vortex center. Two parameters, two-phase absolute vortex flux and swirl number, have been proposed to quantitatively describe the decay in a gas-liquid two-phase swirl flow. The parameters show that swirl decays quickly with increasing gas velocity and decreasing liquid velocity in the two-phase swirl flow. Finally, a correlation has been developed to describe the swirl decay in a gas-liquid two-phase flow. The research results will have an important meaning for heat exchanger and heat transfer enhancement in industry.

中文翻译：

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短扭曲带引起的垂直气液两相流动中的螺旋涡旋和衰减

扭曲带已广泛用于工业和传热增强。但是，大多数研究集中在胶带引起的单相流动上。带引起的气液两相流中的流动特性在很大程度上未得到探索。在这项工作中，通过数值模拟研究了由短扭曲带引起的气液两相涡流中的涡旋运动和衰减特性，并提出了用于定量描述两相涡流中的衰减的两个参数。 。计算结果表明，两个同向旋转的螺旋旋涡出现并保留在旋流中，这些旋涡显着影响液体的分布。液膜厚度的两个峰在周向上出现，并且液膜沿流向逐渐变得均匀。低压芯位于液膜较厚的区域附近，而不是涡旋中心。提出了两个参数，即两相绝对涡流和旋流数，以定量描述气液两相旋流的衰减。参数表明，在两相旋流中，旋流随着气体速度的增加和液体速度的降低而迅速衰减。最后，已开发出一种相关性来描述气液两相流中的旋涡衰减。研究结果对工业换热和传热增强具有重要意义。参数表明，在两相旋流中，旋流随着气体速度的增加和液体速度的降低而迅速衰减。最后，已开发出一种相关性来描述气液两相流中的旋涡衰减。研究成果对工业换热和传热的提高具有重要意义。参数表明，在两相旋流中，旋流随着气体速度的增加和液体速度的降低而迅速衰减。最后，已开发出一种相关性来描述气液两相流中的旋涡衰减。研究结果对工业换热和传热增强具有重要意义。