INTERFACE DYNAMICS OF CAPILLARY-FLOW IN A TUBE UNDER NEGLIGIBLE GRAVITY CONDITION

This paper describes the dynamics of liquid driven by capillary force in a tube when the gravity effect is negligible. The movement of a gas-liquid interface in a horizontal tube has been investigated. A theoretical analysis of interface dynamics is presented where dimensionless variables representing time, distance, and driving force are introduced, and a unique functional relation similar to Bosanquet’s is derived. Self-advancing, self- and forced-receding experiments were carried out with distilled water and methyl alcohol as the test liquids in Pyrex glass, quartz, and Teflon tubes with inner diameters ranging from 0.5-4.0 mm. The movement of the gas-liquid interface position was observed and compared with the dimensionless relation. The difference caused by inner surface conditions was clearly found. The experimental results of advancing interface under wet inner surface conditions show good agreement with the theory. © 1994 by Academic Press, Inc.