, realistic conditions.
The evolution of monosized droplets falling in a coflow with
controllable properties was studied by means of an optical system
for recording droplet images and other techniques (e.g., soot sampling,
not used in this work). A piezoelectric device was used to
generate monosized droplets in the range 60–180 lm. With the
exception of the results shown in Figs. 2 and 3 for 150 lm, all
the other tests were conducted with initial droplet size
d0 180 lm. Due to the high viscosity, the droplet generator had
to be heated to 50–80 C in order to properly atomize the different
glycerol samples and blends. The shape and amplitude of the voltage
signal fed to the piezoelectric atomizer were adjusted to
approach as closely as possible the nominal diameters (150,
180 lm), typically with deviations