Shock-induced drop size and distributions

Abstract

We use an integral analysis of conservation equations of mass and energy, to determine the drop size and distributions during shock-induced drop break-up. The result is an updated form for the drop size as a function of its final velocity, from a series of work applied to various atomization geometries. Comparisons with experimental data demonstrate the validity and utility of this method. The shock-induced drop size and distributions can be predicted within reasonable accuracy as a function of the drop velocity ratio and fluid properties. The result also illustrates the dynamical process of kinetic energy deficit transferred to the surface tension energy, and the skewing of the drop size distribution due to the non-linear dependence on velocity ratio.

Novelty and Significance

Shock-induced liquid break-up occurs in high-speed combustion devices, and it is an important issue to determine the drop size during this process as it represents the initial condition for evaporation and combustion processes. Yet, due to the length scales at which surface tension acts, numerical simulations of drop formation are computationally quite expensive. Current approach provides an analytical method for determination of the drop size, without modeling or extensive numerics. The derived formula can be used as an atomization algorithm in computational framework, vastly reducing the time and cost of simulating the liquid break-up processes.