Ultimate velocity of drops in stationary liquid media

Publisher Website
Google Scholar
Abstract
The effects of high field viscosity and of low inter‐facial tension on the terminal velocity of single liquid drops falling through stationary liquid fields were investigated. Drops of tetrachloroethylene, ranging from 0.08 cm. to 1.4 cm. equivalent diameter, were allowed to fall through four different types of field fluids made by the addition of carboxy methyl cellulose, Lytron 890, corn syrup, and glycerine to water. Viscosities varied from 41.3 to 514 centipoises.Low interfacial tension systems were ethylchloroacetate‐water, furfural‐water, and benzyl alcohol‐water with interfacial tensions of 16.43, 5.70, and 4.25 dynes per cm. respectively.For systems of high field viscosity, the usual drag curve appears to be more useful than the correlation proposed by Hu and Kintner. For systems of low interfacial tension (below 20 dynes/cm.) and low field viscosity (of the order of one centipoise) the latter serves to correlate accurately the data of 25 systems.A comparison of the pour technique with the usual nozzle method for the introduction of drops resulted in a terminal velocity difference of less than three percent. Wall proximity corrections were made when necessary.