化工学报2019，Vol.70Issue(12)：4565-4574,10.DOI:10.11949/0438-1157.20190658
低Reynolds数下水平管降膜滴状流动的实验研究
Experimental study on droplet flow pattern of horizontal tube falling film flow with low Reynolds number
摘要
Abstract
To fully understand the drop-like flow phenomenon of the horizontal tube falling film, this paper uses water as the experimental fluid, and uses a high-speed high-definition camera to visualize the drop-shaped flow of the horizontal tube under different pipe spacings. The droplet flow in low Reynolds number Re≤200 and tube spacing s≤40 mm is observed. Based on the different flow characteristic, the droplet flow can be divided into accumulation droplet flow, incomplete droplet flow, pendant droplet flow, complete droplet flow and incomplete retracting droplet flow. According to the experimental results, the partition map of droplet flow is presented. The concept of separation length is proposed, and the effect of flow rate on separation length is discussed. The relationship between dropping site spacing and flow rate in droplet flow at low Reynolds number was studied. The results show that the flow pattern of droplet flow is influenced not only by flow rate but also by tube spacing. With the increase of tube spacing in Re≤120, the flow patterns between tubes are converted from accumulation droplet flow to incomplete droplet flow to pendant droplet flow, and to complete droplet flow. When 25 mm≤s≤40 mm, as the flow rate increases, the flow patterns are successively converted from incomplete droplet flow to pendant droplet flow, and to incomplete retracting droplet flow. The separation length increases linearly in two stages with the increase of Re. The growth rate in Re≤60 is smaller than it in 60<Re≤140. The correlation of separation length with Re is established in this paper. In addition, the dropping site spacing of droplet flow is investigated. The dropping site spacing decreases with the increase of flow rate in Re≤100, and remains stable in the range of 100<Re≤200. Meanwhile, the dropping site spacing of droplet flow with Re is established.关键词
水平管降膜/滴状流动形态/分离长度/滴落点间距Key words
horizontal tube falling film/ droplet flow pattern/ separation length/ dropping site spacing分类
能源科技引用本文复制引用
柳山林,牟兴森,沈胜强,梁斌,包天杰,倪兵..低Reynolds数下水平管降膜滴状流动的实验研究[J].化工学报,2019,70(12):4565-4574,10.基金项目
国家自然科学基金重点项目(51936002, 51406024) （51936002, 51406024）
