THE SHAPE, STABILITY AND BREAKAGE OF PENDANT LIQUID BRIDGES

Pendant liquid bridges are defined as pendant drops supporting a solid axisymmetric endplate at their lower end. The stability and shape pro perties of such bridges are defined in terms of the capillary properti es of the system and of the mass and radius of the lower free-floating endplate. The forces acting in the pendant liquid bridge are defined exactly and expressed in dimensionless form. Numerical analysis has be en used to derive the properties of a given bridge and it is shown tha t as the bridge grows by adding more liquid to the system a maximum vo lume is reached. At this maximum volume, the pendant bridge becomes un stable with the length of the bridge increasing spontaneously and irre versibly at constant volume. Finally the bridge breaks with the format ion of a satellite drop or an extended thread. The bifurcation and bre akage processes have been recorded using a high-speed video camera wit h a digital recording rate of up to 6000 frames per second. The detail s of the shape of the bridge bifurcation and breakage for many pendant bridge systems have been recorded and it is shown that satellite drop formation after rupture is not always viscosity dependent. Bifurcatio n and breakage in simulated low gravity demonstrated that breakage was very nearly symmetrical about a plane through the middle of the penda nt bridge.