矩形截面螺旋通道内弹状流的流动特性

对水平放置矩形截面螺旋通道内弹状流的流动特性进行了实验研究.通过实验获得了不同周角下的气弹演变过程和局部流动特征,结果表明,其流动特性会随着螺旋周角位置的变化而变化.根据实验数据分析发现,同一工况下,不同转角气弹的运动速度、频率和长度分布不尽相同.重力和离心力的相对大小决定着内外壁面液膜的厚度,给出了同一条件下,不同时刻的液膜厚度的演变过程.最后对下降液膜的运动速度展开了分析研究,在螺旋上升过程中,液膜下降速度逐渐减小,在螺旋下降段,液膜速度明显增大.

Flow characteristics of slug flow in helical rectangular channel

Experimental investigations on slug flow were carried out in horizontal helical rectangular channel by using high speed flow visualization. Evolution of slug in the whole helical rectangular channel was presented and the fine features of slug flow in different positions were illustrated. The slug characteristics changed along the axial direction due to the combined effects of gravitational and centrifugal force. Based on the experimental data, slug velocity, slug frequency and length distribution in different positions were given. The present topography measurement illustrated the evolution features of liquid film thickness, which was determined by the effect of centrifugal force and gravity. Liquid film falling velocity decreased as the slug moved upward and was visibly increasing in the downward flow.