%0 Journal Article %A Cheng, Xu %A Chen, Yan %A Li, Hongru %A Li, Baixue %A Han, Xi %A Xin, Gongming %D 2019 %I Begell House %K capillary flow, capillary tube, variable diameters, flow characteristic %N 13 %P 1627-1638 %R 10.1615/JPorMedia.2019026774 %T INVESTIGATION ON CAPILLARY FLOW IN TUBES WITH VARIABLE DIAMETERS %U https://www.dl.begellhouse.com/journals/49dcde6d4c0809db,46e8dbb416798922,2cb4816368b86689.html %V 22 %X Capillary flow in single cylindrical tubes with constant diameters (0.2 and 0.4 mm) was investigated experimentally, using alcohol as working fluid. The flow behavior was recorded by a high-speed camera in terms of height-time relationship and compared with an existing theoretical model. The experimental results illustrated good consistency with the model. Next, experiments were conducted in variable diameter tubes (expanding from 0.2 to 0.4 mm and contracting from 0.4 to 0.2 mm) and the capillary flow characteristics were analyzed. Before reaching the change point the flow showed a similar trend as that in constant diameter tubes, but it demonstrated different features after passing the change point. It was also found that the location of change point had great influence on the flow behavior. %8 2019-11-27