The dynamics of head-on collision between two identical droplets was experimentally and computationally investigated, with particular emphasis on the transitions from merging to bouncing to merging again as the collision Weber number was increased. Experimentally the stroboscopically illuminated microphotographic images of two colliding droplet streams, generated through the ink-jet printing technique, were acquired with adequate temporal resolution of the collision event such that the instant at which the droplets merged was identified. Using this empirical information as an input, the simulated collision images agree well with the experimental observations, and allow investigation of the collision flow field including the energy budget. Detailed study of the dynamics of the colliding interfacial surfaces revealed the fundamental differences between the soft and hard collisions that led to merging, and suggested that effects of rarefied flow and gas compressibility could be responsible for the interfaces to approach to a sufficiently close distance at which van der Waals force would become effective and thereby effect merging through rupturing of the surfaces.
|Number of pages
|Published - Jul 1 2004
|42nd AIAA Aerospace Sciences Meeting and Exhibit - Reno, NV, United States
Duration: Jan 5 2004 → Jan 8 2004
|42nd AIAA Aerospace Sciences Meeting and Exhibit
|1/5/04 → 1/8/04
All Science Journal Classification (ASJC) codes