  Spray formation and atomization in a gas-liquid mixing layer is an important
fundamental problem of multiphase flows. It is highly desirable to visualize
the detailed atomization process and to analyze the instabilities and
mechanisms involved, and massive numerical simulations are required, in
addition to experiment. Rapid development of numerical methods and computer
technology in the past decades now allows large-scale three-dimensional direct
numerical simulations of atomization to be performed. Nevertheless, the
fundamental question, whether all the physical scales involved in the primary
breakup process are faithfully resolved, remains unclear. In the present study,
we conduct direct numerical simulations of spray formation in a gas-liquid
mixing layer with state-of-the-art computational resources (using up to 4
billion cells and 16384 cores), in order to obtain a high-fidelity numerical
closeup of the detailed mechanisms of spray formation. We also aim to examine
whether present computational resources are sufficient for a fully resolved
direct numerical simulation of atomization.
