EAPSI: Development of a novel method for predicting liquid drop merging upon impact

Deisenroth David C, Houghton MI

Investigators

Abstract

Small liquid drops are prolific in thermal management systems, aerosol products, and fuel injection systems. Understanding the physics behind drop interaction and controlling that interaction in these common applications is critical to decreasing development costs and improving performance. The objective of this research is to test a method for predicting whether or not the drops merge to form a single, larger drop, upon impact. The current topic of interest is a single liquid drop falling vertically and impacting a drop resting on a surface. Previous research has developed maps to characterize whether the drops merge or if the falling drop bounces off. These studies have resulted in incomplete descriptions of drop behavior. Impacting drops will be imaged at high speeds using a well-established method in Dr. Seong Hyuk Lee's Laboratory at Chung-Ang University in Seoul, South Korea. Preliminary data gathered with the experimental setup at Dr. Seong Hyuk Lee's lab show the novel prediction method may better predict drop merging upon impact, which gives new insight into the physics behind drop interaction. A more effective map for predicting drop coalescence will be produced using a novel method of nondimensionalizing the impact parameters. The goal is to use the impact parameters to separate coalescing impacts from non-coalescing impacts. The impact parameters include mass-center offset, relative size, impact velocity, surface tension, viscosity, and density. The novel scaling method is based the Weber number of the falling drop, which is modified by a factor which accounts for the inertia of the resting drop. This NSF EAPSI award is funded in collaboration with the National Research Foundation of Korea.