Journal article
Fast droplet impact onto slowly moving deep pools
- Abstract:
- When a fast droplet impacts a pool, the resulting ejecta sheet dynamics determine the final impact outcome. At low Capillary numbers, the ejecta sheet remains separate from a deep static pool, while at higher values it develops into a lamella. Here, we show that the common natural scenario of a slowly moving deep pool can change the upstream impact outcome, creating highly three-dimensional dynamics no longer characterised by a single descriptor. By considering how pool movement constrains the evolution of the ejecta sheet angle, we reach a length-scale invariant parameterisation for the upstream transition that holds for a wide range of fluids and impact conditions. Direct numerical simulations show similar dynamics for an equivalent oblique impact, indicating that the air boundary layer above a moving pool does not play a decisive role for low pool-droplet speed ratios. Our results also provide insight into the physical mechanisms that underpin pool impact outcomes more generally.
- Publication status:
- Accepted
- Peer review status:
- Peer reviewed
Actions
Authors
+ U.S. National Science Foundation
More from this funder
- Funder identifier:
- https://ror.org/021nxhr62
- Grant:
- NSF CBET-2123371
+ John Fell Fund, University of Oxford
More from this funder
- Funder identifier:
- https://ror.org/052gg0110
- Grant:
- 0014320
+ Engineering and Physical Sciences Research Council
More from this funder
- Funder identifier:
- https://ror.org/0439y7842
- Grant:
- EP/W016036/1
- UKRI424
- Publisher:
- Cambridge University Press
- Journal:
- Journal of Fluid Mechanics More from this journal
- Acceptance date:
- 2026-04-21
- EISSN:
-
1469-7645
- ISSN:
-
0022-1120
- Language:
-
English
- Pubs id:
-
2410685
- Local pid:
-
pubs:2410685
- Deposit date:
-
2026-04-23
- ARK identifier:
If you are the owner of this record, you can report an update to it here: Report update to this record