Lp. Hsiang et Gm. Faeth, DROP DEFORMATION AND BREAKUP DUE TO SHOCK-WAVE AND STEADY DISTURBANCES, International journal of multiphase flow, 21(4), 1995, pp. 545-560
An experimental study of drop deformation properties induced by both s
hock wave and steady disturbances is described. Three test facilities
were used, as follows: a shock tube facility for measurements of effec
ts of shock wave disturbances on drops in gases, a 10 m high drop tube
facility for measurements of effects of steady disturbances on drops
in gases and a Im high drop tube facility for measurements of effects
of steady disturbances on drops in liquids. Various dispersed and cont
inuous phase gases and liquids were considered to provide dispersed/co
ntinuous phase density ratios of 1.15-12,000, Ohnesorge numbers of 0.0
006-600, Weber numbers of 0.004-700 and Reynolds numbers of 0.03-16,00
0. At low Ohnesorge numbers (<0.1) for all types of disturbances, sign
ificant drop deformation (5%) began at Weber numbers of roughly unity,
with the deformation regime ending due to the onset of breakup at Web
er numbers of 10-20. These transitions were relatively unaffected by t
he Ohnesorge number for steady disturbances, however, increasing Ohnes
orge numbers caused progressive increases of the Weber number range fo
r both deformation and breakup regimes for shock wave disturbances-an
effect that could be explained using phenomenological theory. Another
transition, between dome- and bowl-shaped drops (related to the transi
tion between bag and shear breakup), was correlated mainly in terms of
Weber and Reynolds numbers for present conditions. Drop deformation f
or steady disturbances was relatively independent of dispersed/continu
ous phase density ratios but generally was smaller than for shock wave
disturbances at comparable conditions due to the absence of overshoot
from inertial effects. In contrast,drop drag coefficients, normalized
by the drag coefficient of a solid sphere at the same Reynolds number
, were correlated quite well by the degree of deformation alone.