  The depressurization of the surrounding chamber or superheating of the
injected liquid is responsible for the flashing of the sprays, which promotes
micro-explosion of many bubbles near free-surface and thereby leading to
primary atomization of sprays. In this work, we propose a mathematical model,
and the Dirichlet hyperboloids are used to explain the micro-explosion process
while the external flashing phenomenon is observed in superheated liquid jets.
The developed mathematical model is implemented in the Lagrangian framework to
study the spray structure, and the results of numerical simulations are found
to be in good agreement with the experimental results from the literature. In
the onset region of a fully flashing regime, the bell-shaped spray structure
becomes eminent due to increased drag on the high radial-velocity ejected
droplets. However, at a lower degree of superheat, the droplet size is found to
increase with a decrease in ambient pressure. Whereas the opposite trend is
observed at a higher degree of superheat.
