Liquid bridge formation

Abstract

The formation of a liquid bridge is obviously the first step in the experimentation of the different aspects of the liquid bridge dynamics. Among the several candidate procedures of formation, the so-called 'cylindrical formation' has been selected; liquid is injected inside of the bridge through one of the supporting disks whereas simultaneously one of the disks is moved apart from the other at the proper speed to keep the volume of liquid inside the column, the same as that of the cylinder limited by both disks. Besides its own fluid mechanics interest (interplay between a jet and an interface), the results of this study would be very useful for experimenters in order to reduce the experiment preparation phase, as the total time allowed is scarce in most often used reduced gravity facilities (parabolic flights, sounding rockets and so on). A simplified theoretical model of the problem is presented which is valid in a flow regime limited in range by the Reynolds number of the injection jet. The existence of contiguous regimes and the influence of Ohnesorge number are suggested. This characterization has been deduced from the experiments performed by using the neutral buoyancy technique on earth and helps to explain the behavior observed during experiments performed on microgravity conditions onboard sounding rockets (TEXUS).