A solvable model of axisymmetric and non-axisymmetric droplet bouncing
We introduce a solvable Lagrangian model for droplet bouncing. The model predicts that, for an axisymmetric drop, the contact time decreases to a constant value with increasing Weber number, in qualitative agreement with experiments, because the system is well approximated as a simple harmonic oscil...
| Main Authors: | , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
Royal Society of Chemistry
2017
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| _version_ | 1797062570112188416 |
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| author | Andrew, M Yeomans, J Pushkin, D |
| author_facet | Andrew, M Yeomans, J Pushkin, D |
| author_sort | Andrew, M |
| collection | OXFORD |
| description | We introduce a solvable Lagrangian model for droplet bouncing. The model predicts that, for an axisymmetric drop, the contact time decreases to a constant value with increasing Weber number, in qualitative agreement with experiments, because the system is well approximated as a simple harmonic oscillator. We introduce asymmetries in the velocity, initial droplet shape, and contact line drag acting on the droplet and show that asymmetry can often lead to a reduced contact time and lift-off in an elongated shape. The model allows us to explain the mechanisms behind non-axisymmetric bouncing in terms of surface tension forces. Once the drop has an elliptical footprint the surface tension force acting on the longer sides is greater. Therefore the shorter axis retracts faster and, due to the incompressibility constraints, pumps fluid along the more extended droplet axis. This leads to a positive feedback, allowing the drop to jump in an elongated configuration, and more quickly. |
| first_indexed | 2024-03-06T20:47:24Z |
| format | Journal article |
| id | oxford-uuid:365edaf2-3974-408f-aa5c-79bb16975e67 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T20:47:24Z |
| publishDate | 2017 |
| publisher | Royal Society of Chemistry |
| record_format | dspace |
| spelling | oxford-uuid:365edaf2-3974-408f-aa5c-79bb16975e672022-03-26T13:37:31ZA solvable model of axisymmetric and non-axisymmetric droplet bouncingJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:365edaf2-3974-408f-aa5c-79bb16975e67EnglishSymplectic Elements at OxfordRoyal Society of Chemistry2017Andrew, MYeomans, JPushkin, DWe introduce a solvable Lagrangian model for droplet bouncing. The model predicts that, for an axisymmetric drop, the contact time decreases to a constant value with increasing Weber number, in qualitative agreement with experiments, because the system is well approximated as a simple harmonic oscillator. We introduce asymmetries in the velocity, initial droplet shape, and contact line drag acting on the droplet and show that asymmetry can often lead to a reduced contact time and lift-off in an elongated shape. The model allows us to explain the mechanisms behind non-axisymmetric bouncing in terms of surface tension forces. Once the drop has an elliptical footprint the surface tension force acting on the longer sides is greater. Therefore the shorter axis retracts faster and, due to the incompressibility constraints, pumps fluid along the more extended droplet axis. This leads to a positive feedback, allowing the drop to jump in an elongated configuration, and more quickly. |
| spellingShingle | Andrew, M Yeomans, J Pushkin, D A solvable model of axisymmetric and non-axisymmetric droplet bouncing |
| title | A solvable model of axisymmetric and non-axisymmetric droplet bouncing |
| title_full | A solvable model of axisymmetric and non-axisymmetric droplet bouncing |
| title_fullStr | A solvable model of axisymmetric and non-axisymmetric droplet bouncing |
| title_full_unstemmed | A solvable model of axisymmetric and non-axisymmetric droplet bouncing |
| title_short | A solvable model of axisymmetric and non-axisymmetric droplet bouncing |
| title_sort | solvable model of axisymmetric and non axisymmetric droplet bouncing |
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