Drop Impact onto a Substrate Wetted by Another Liquid: Flow in the Wall Film
The impact of a drop onto a liquid film is relevant for many natural phenomena and industrial applications such as spray painting, inkjet printing, agricultural sprays, or spray cooling. In particular, the height of liquid remaining on the substrate after impact is of special interest for painting a...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-10-01
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| Series: | Colloids and Interfaces |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2504-5377/6/4/58 |
| _version_ | 1797460814586707968 |
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| author | Bastian Stumpf Jeanette Hussong Ilia V. Roisman |
| author_facet | Bastian Stumpf Jeanette Hussong Ilia V. Roisman |
| author_sort | Bastian Stumpf |
| collection | DOAJ |
| description | The impact of a drop onto a liquid film is relevant for many natural phenomena and industrial applications such as spray painting, inkjet printing, agricultural sprays, or spray cooling. In particular, the height of liquid remaining on the substrate after impact is of special interest for painting and coating but also for applications involving heat transfer from the wall. While much progress has been made in explaining the hydrodynamics of drop impact onto a liquid film of the same liquid, the physics of drop impact onto a wall film with different material properties is still not well understood. In this study, drop impact onto a very thin liquid film of another liquid is investigated. The thickness of the film remaining on a substrate after drop impact is measured using a chromatic-confocal line sensor. It is interesting that the residual film thickness does not depend on the initial thickness of the wall film, but strongly depends on its viscosity. A theoretical model for the flow in the drop and wall film is developed which accounts for the development of viscous boundary layers in both liquids. The theoretical predictions agree well with the experimental data. |
| first_indexed | 2024-03-09T17:10:25Z |
| format | Article |
| id | doaj.art-89215f641f5f4bc0b853260108a1f69e |
| institution | Directory Open Access Journal |
| issn | 2504-5377 |
| language | English |
| last_indexed | 2024-03-09T17:10:25Z |
| publishDate | 2022-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Colloids and Interfaces |
| spelling | doaj.art-89215f641f5f4bc0b853260108a1f69e2023-11-24T14:06:31ZengMDPI AGColloids and Interfaces2504-53772022-10-01645810.3390/colloids6040058Drop Impact onto a Substrate Wetted by Another Liquid: Flow in the Wall FilmBastian Stumpf0Jeanette Hussong1Ilia V. Roisman2Institute for Fluid Mechanics and Aerodynamics, Technical University of Darmstadt, 64287 Darmstadt, GermanyInstitute for Fluid Mechanics and Aerodynamics, Technical University of Darmstadt, 64287 Darmstadt, GermanyInstitute for Fluid Mechanics and Aerodynamics, Technical University of Darmstadt, 64287 Darmstadt, GermanyThe impact of a drop onto a liquid film is relevant for many natural phenomena and industrial applications such as spray painting, inkjet printing, agricultural sprays, or spray cooling. In particular, the height of liquid remaining on the substrate after impact is of special interest for painting and coating but also for applications involving heat transfer from the wall. While much progress has been made in explaining the hydrodynamics of drop impact onto a liquid film of the same liquid, the physics of drop impact onto a wall film with different material properties is still not well understood. In this study, drop impact onto a very thin liquid film of another liquid is investigated. The thickness of the film remaining on a substrate after drop impact is measured using a chromatic-confocal line sensor. It is interesting that the residual film thickness does not depend on the initial thickness of the wall film, but strongly depends on its viscosity. A theoretical model for the flow in the drop and wall film is developed which accounts for the development of viscous boundary layers in both liquids. The theoretical predictions agree well with the experimental data.https://www.mdpi.com/2504-5377/6/4/58drop impactresidual filmfilm dynamicsthin films |
| spellingShingle | Bastian Stumpf Jeanette Hussong Ilia V. Roisman Drop Impact onto a Substrate Wetted by Another Liquid: Flow in the Wall Film Colloids and Interfaces drop impact residual film film dynamics thin films |
| title | Drop Impact onto a Substrate Wetted by Another Liquid: Flow in the Wall Film |
| title_full | Drop Impact onto a Substrate Wetted by Another Liquid: Flow in the Wall Film |
| title_fullStr | Drop Impact onto a Substrate Wetted by Another Liquid: Flow in the Wall Film |
| title_full_unstemmed | Drop Impact onto a Substrate Wetted by Another Liquid: Flow in the Wall Film |
| title_short | Drop Impact onto a Substrate Wetted by Another Liquid: Flow in the Wall Film |
| title_sort | drop impact onto a substrate wetted by another liquid flow in the wall film |
| topic | drop impact residual film film dynamics thin films |
| url | https://www.mdpi.com/2504-5377/6/4/58 |
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