Interface Dynamics of Capillary Driven Flow in a Tube

Abstract

This paper describes the dynamics of liquid driven by capillary force in a tube. The movement of a gas-liquid interface in a horizontal tube as a result of capillary action has been investigated. A theoretical analysis of the interface dynamics is presented where dimensionless numbers representing time and distance scales are introduced, and a unique functional relation is derived. Experiments were carried out with distilled water as the test liquid in glass tubes of inner diameter from 0.5mm to 4.0mm. The position of the gas-liquid interface as a function of time was observed. The experimental results agree well with theory.