Electric Field Effect on the Dynamics of the Structural Flow Components in the Case of Gravity-Induced Separation of a Water Drop

Abstract

The high-speed videorecording method is used to investigate the effect of an electrostatic field (with the potential Φ = 0, 16, and 18 kV) on the flow geometry in the case of gravity-induced separation of a drop from a capillary tube. The flow videograms are analyzed and the dimensions of the characteristic structural elements, that is, the drops themselves, a bridge, and satellites, are determined. The oscillations of the linear dimensions and the mother liquid volume after drop separation are traced at \(\Phi = \) 0 and 18 kV. Both fundamental frequencies and their harmonics are observable in the spectra. It is found that small (12%) variations in the potential value lead to qualitative variations in the flow pattern and, in particular, to direct separation of the drop from the mother liquid without the formation of a bridge. At a constant liquid discharge in the capillary the dimensions of the separated drops decrease with increase of the voltage. The experiments show the possibility of the fine controlling of drop flows using electrostatic fields.