Abstract The flow pattern of gas–liquid mixtures across a single-orifice plate in horizontal pipes, in particular the change in flow patterns downstream of a single-orifice plate (DSOP) when the upstream is in a common intermittent flow, has not been elucidated hitherto. In this study, a visualization experiment was performed using air and water as the gas and liquid phases, respectively. The effects of superficial gas velocity, superficial liquid velocity, and orifice-pipe diameter ratio on the flow pattern transition in DSOPs were experimentally examined in ranges of 0.07–0.51 m/s, 0.35–1.77 m/s, and 0.30–0.61, respectively. Results show that there are two different trends, i.e., stratified and dispersed, in DSOPs for an intermittent upstream flow. It is interesting that in DSOPs, intermittent flows tend to disappear, or, stratified flows can transit to bubble flows directly. In DSOPs, most of the region corresponding to an intermittent flow for a simple horizontal pipe becomes the region of a completely dispersed bubble flow, indicating that the throttling of orifice plates has excellent performance on bubble breakup. Moreover, a novel dimensionless criterion is proposed to predict the transition between stratified and bubble flows in DSOPs.

中文翻译：

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间歇上游流下水平管单孔板下游气液流型可视化实验

摘要 气液混合物在水平管道中穿过单孔板的流型，特别是上游为普通间歇流时单孔板（DSOP）下游流型的变化尚未阐明。迄今为止。在这项研究中，分别使用空气和水作为气相和液相进行了可视化实验。分别在 0.07–0.51 m/s、0.35–1.77 m/s 和 0.30–0.61 的范围内实验研究了表观气体速度、表观液体速度和孔管直径比对 DSOP 中流型转变的影响. 结果表明，对于间歇性上游流，DSOPs 有两种不同的趋势，即分层和分散。有趣的是，在 DSOP 中，间歇性流量趋于消失，或者，分层流可以直接转变为气泡流。在DSOPs中，与简单水平管断续流相对应的区域大部分变成了完全分散的气泡流区域，表明孔板节流对气泡破碎具有优良的性能。此外，提出了一种新的无量纲标准来预测 DSOP 中分层流和气泡流之间的过渡。