Drop impact is a canonical problem in fluid mechanics, with numerous applications
in industrial as well as natural phenomena. The extremely simple initial
configuration of the experiment can produce a very large variety of fast and complex
dynamics. Scientific progress was made in parallel with major improvements
in imaging and computational technologies. Most recently, high-speed imaging
video cameras have opened the exploration of new phenomena occurring at the
micro-second scale, and parallel computing allowed realistic direct numerical simulations
of drop impacts. We combine these tools to bring a new understanding
of two fundamental aspects of drop impacts: splashing and air entrapment.
The early dynamics of a drop impacting on a liquid pool at high velocity
produces an ejecta sheet, emerging horizontally in the neck between the drop and
the pool. We show how the interaction of this thin liquid sheet with the air, the
drop or the pool, can produce micro-droplets and bubble rings. Then we detail
how the breakup of the air film stretched between the drop and the pool for lower
impact velocities can produce a myriad of micro-bubbles.
Date of Award | Mar 2013 |
---|
Original language | English (US) |
---|
Awarding Institution | - Physical Sciences and Engineering
|
---|
Supervisor | Sigurdur Thoroddsen (Supervisor) |
---|
- Drop Impact
- Bubble Entrapment
- Vortex Street
- Gerris
- Splashing
- Film Breakup
- ejecta sheet
- slingshot mechanism
- bubble ring
- air toroid
- liquid toroid
- VOF
- vortex shedding
- air entrapment
- Mesler entrainment