Droplet impact dynamics on shallow pools
When a fast droplet impacts a pool of the same fluid, a thin ejecta sheet that dominates the early-time dynamics emerges within the first few microseconds. Fluid and impact properties are known to affect its evolution; we experimentally reveal that the pool depth is a critical factor too. Whilst eje...
| Main Authors: | , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
Cambridge University Press
2023
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| _version_ | 1826311275802525696 |
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| author | Sykes, TC Cimpeanu, R Fudge, B Castrejon-Pita, JR Castrejon Pita, A |
| author_facet | Sykes, TC Cimpeanu, R Fudge, B Castrejon-Pita, JR Castrejon Pita, A |
| author_sort | Sykes, TC |
| collection | OXFORD |
| description | When a fast droplet impacts a pool of the same fluid, a thin ejecta sheet that dominates the early-time dynamics emerges within the first few microseconds. Fluid and impact properties are known to affect its evolution; we experimentally reveal that the pool depth is a critical factor too. Whilst ejecta sheets can remain separate and subsequently fold inwards on deeper pools, they instead develop into outward-propagating lamellae on sufficiently shallow pools, undergoing a transition that we delineate by comprehensively varying impact inertia and pool depth. Aided by matching direct numerical simulation results, we find that this transition stems from a confinement effect of the pool base on the impact-induced pressure, which stretches the ejecta sheet to restrict flow into it from the droplet on sufficiently shallow pools. This insight is also applied to elucidate the well-known transition due to Reynolds number. |
| first_indexed | 2024-03-07T08:05:56Z |
| format | Journal article |
| id | oxford-uuid:f8b2fc5d-be0d-4e02-9989-cf9ec62c6c71 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T08:05:56Z |
| publishDate | 2023 |
| publisher | Cambridge University Press |
| record_format | dspace |
| spelling | oxford-uuid:f8b2fc5d-be0d-4e02-9989-cf9ec62c6c712023-10-25T13:28:52ZDroplet impact dynamics on shallow poolsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:f8b2fc5d-be0d-4e02-9989-cf9ec62c6c71EnglishSymplectic ElementsCambridge University Press2023Sykes, TCCimpeanu, RFudge, BCastrejon-Pita, JRCastrejon Pita, AWhen a fast droplet impacts a pool of the same fluid, a thin ejecta sheet that dominates the early-time dynamics emerges within the first few microseconds. Fluid and impact properties are known to affect its evolution; we experimentally reveal that the pool depth is a critical factor too. Whilst ejecta sheets can remain separate and subsequently fold inwards on deeper pools, they instead develop into outward-propagating lamellae on sufficiently shallow pools, undergoing a transition that we delineate by comprehensively varying impact inertia and pool depth. Aided by matching direct numerical simulation results, we find that this transition stems from a confinement effect of the pool base on the impact-induced pressure, which stretches the ejecta sheet to restrict flow into it from the droplet on sufficiently shallow pools. This insight is also applied to elucidate the well-known transition due to Reynolds number. |
| spellingShingle | Sykes, TC Cimpeanu, R Fudge, B Castrejon-Pita, JR Castrejon Pita, A Droplet impact dynamics on shallow pools |
| title | Droplet impact dynamics on shallow pools |
| title_full | Droplet impact dynamics on shallow pools |
| title_fullStr | Droplet impact dynamics on shallow pools |
| title_full_unstemmed | Droplet impact dynamics on shallow pools |
| title_short | Droplet impact dynamics on shallow pools |
| title_sort | droplet impact dynamics on shallow pools |
| work_keys_str_mv | AT sykestc dropletimpactdynamicsonshallowpools AT cimpeanur dropletimpactdynamicsonshallowpools AT fudgeb dropletimpactdynamicsonshallowpools AT castrejonpitajr dropletimpactdynamicsonshallowpools AT castrejonpitaa dropletimpactdynamicsonshallowpools |