  The research is devoted to the generation of fine particles and droplet flows
with specified characteristics for a wide range of scientific problems. The
aspects of aerodynamic fine atomization and the effects of atomizing gas
density, gas velocity and mass flow rate, and liquid film thickness on the
droplet formation are investigated. The hypothesis of highly efficient
utilization of secondary droplets from a coarse polydisperse flow to produce
fine particles is suggested and experimentally confirmed. A prototype device to
implement the idea of separating the desired droplets fraction from a primary
polydisperse flow was developed. In the case of fine liquid atomization, the
developed spraying system enabled an increase in the gas-droplet flow
concentration. The possibility of producing particles with different
dispersiveness and morphology by employing the methods of spray separation and
dilute solution atomization is demonstrated. The criteria of the system
settings to generate the droplet flow with specified characteristics were
determined. A Laval nozzle design is suggested for liquid atomization. A series
of numerical experiments showed that a significant decrease in gas pressure
(density) at the nozzle outlet provides an increase in the gas flow rate. The
numerical estimation showed that the Laval nozzle proposed can improve the fine
atomization efficiency by 30 percent.

Fluid Dynamics