Ballistic imaging of liquid breakup processes in dense sprays
Journal article, 2009
Ballistic imaging is the name applied to a category of optical techniques that were originally developed
for medical applications. Recently, ballistic imaging was adapted to acquire instantaneous images of the
liquid core inside atomizing sprays; a region that has been heretofore inaccessible to spray researchers.
An important difference between spray research and the medical imaging problem is the need for high fidelity
single-shot (within 10 ls) imaging in a spray whereas stationary tissue images can be averaged. Transient
ballistic imaging diagnostics have been used to reveal details of the primary breakup process in a
LOX injector, a turbulent water jet, a water jet in cross-flow, a transient diesel fuel spray, a rocket fuel
injector, and an aerated spray. This paper briefly discusses various methods for imaging the liquid core,
it introduces ballistic imaging and provides specific examples, it describes detailed studies of photon transmission through dense media, and it then discusses incorporation of those results into a model for a ballistic
imaging instrument that can evaluate and optimize various concepts.