An Experimental Investigation of Impact and Shock-Wave Break-Up of Liquid Drops

摘要

The report describes an experimental investigation into the matter of evaluating sprays. Two particular aspects of the problem were studied: 1) impact break-up of drops when the spray is sampled by means of coated slides, and 2) drop break-up associated with shock waves. The first phase of the work made use of glass slides coated with highly viscous silicone oils to sample individual drops. An empirical equation was established which specifies critical impact velocities for water drops whose diameters lie in the range 350-2270 microns. Extrapolation to smaller drops gives plausible values of critical velocities. The second aspect of the problem was studied in a shock tube. New results were obtained with water and methyl alcohol in the 100-700 micron range of drop diameters. Apparatus was developed which is believed capable of studying shock break-up of considerably smaller drops, perhaps down to 25 microns in diameter. (Author)