Measurements of interfacial dynamics of gas–liquid displacement in a capillary

Abstract

It is also important for boiling flows [8,9] in a wide range of industrial applications.However, Bretherton's model did not take the surface wettability of the capillary wall into consideration. Except for Ratulowski and Chang [3], most of the analytical studies focused on the semi-infinite long bubble model, since Bretherton applied 'Lubrication Approximation' analysis on the trans ition region of a bubble. In this case, it is reasonable to assume a uniform interfacial liquid film under gas-liquid displacement when a plug bubble is moving along the capillary with a relatively large capillary number. However, it depends on the bubble velocity and the capillary's wettability. In this paper, low velocity bubbles with capillary numbers ranging from 0.001 to 0.01, (0.001 < Ca < 0.01) and bubble length range is L > 20 R (long bubble), will be investigated as shown in figure 1.To determine the liquid film thickness in experiments, Bretherton [1] and Schwartz et al [2] measured a plug of a wetting liquid moving along an initially dry glass capillary tube at constant velocity and calculated the liquid film thickness by Measurement Science and Technology

Interfacial Flows of Contact Line Dynamics and Liquid Displacement in a Circular Microchannel

“…To quantitatively analyse the interfacial liquid film displacement behaviour, an optical technique for measuring the interfacial liquid film between the liquid and gas in a circular microchannel is developed recently [13]. The interfacial film dynamics is detected by a very sensitive laser spatial fringe projection technique and a high speed camera.…”