Coalescence of a Ferrofluid Drop at Its Bulk Surface with or without a Magnetic Field

The coalescence of a ferrofluid drop at its bulk surface, with or without a magnetic field, was investigated experimentally by a high-speed camera. Shape deformations of both the pendant ferrofluid drop and the bulk surface in the axial direction were observed during the approaching process even in...

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Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1992. - 39(2023), 1 vom: 10. Jan., Seite 461-468
1. Verfasser: Zhang, Qindan (VerfasserIn)
Weitere Verfasser: Poncin, Souhila, Blanchard, Christian, Ma, Youguang, Li, Huai Z
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2023
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article
Beschreibung
Zusammenfassung:The coalescence of a ferrofluid drop at its bulk surface, with or without a magnetic field, was investigated experimentally by a high-speed camera. Shape deformations of both the pendant ferrofluid drop and the bulk surface in the axial direction were observed during the approaching process even in the absence of a magnetic field. The angle of the upper pendant peak at the first contact decreases with the magnetic flux density, while the lower ferrofluid peak displays an opposite trend. The coalescing width of the ferrofluid drop follows a power-law relationship. The exponent of 0.64 under medium and high magnetic fields as well as the case without magnetic field confirms the inertial regime of drop coalescence. Under the low magnetic field, the significant exponent increasing from 0.59 to 3.02 at about 4 ms is in coincidence with the sudden change to a smooth coalescing section according to the visualized images. A high-speed microparticle image velocimetry (micro-PIV) technique was employed with a transparent model fluid to reveal the flow fields during the drop coalescence instead of opaque ferrofluids
Beschreibung:Date Completed 10.01.2023
Date Revised 11.01.2023
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1520-5827
DOI:10.1021/acs.langmuir.2c02727