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Electro-drop bouncing in low-gravity
- Source :
- Physics of Fluids. 32:062105
- Publication Year :
- 2020
- Publisher :
- AIP Publishing, 2020.
-
Abstract
- We investigate the dynamics of spontaneous jumps of water drops from electrically charged nonwetting dielectric substrates during sudden step reductions in the gravity level. In the free-fall environment of a drop tower, the dynamics of drops subject to external electric fields are dominated by the Coulombic force instead of gravity. These forces lead to a drop bouncing behavior similar to well-known terrestrial phenomena though occurring for much larger drops (∼0.5 ml). We provide a one-dimensional model for the phenomenon, its scaling, and asymptotic estimates for drop time-of-flight in two regimes: at short-times close to the substrate when drop inertia balances the Coulombic force due to net free charge and image charges in the dielectric substrate, and at long-times far from the substrate when drop inertia balances free charge Coulombic force and drag. In both regimes, the dimensionless electrostatic Euler number Eu, which is a ratio of inertia to electrostatic force, appears as a key parameter.
- Subjects :
- Fluid Flow and Transfer Processes
Physics
Mechanical Engineering
Drop (liquid)
media_common.quotation_subject
Computational Mechanics
Dielectric
Mechanics
Condensed Matter Physics
Inertia
Physics::Fluid Dynamics
Mechanics of Materials
Drag
Electric field
Fluid dynamics
Electrohydrodynamics
Dimensionless quantity
media_common
Subjects
Details
- ISSN :
- 10897666 and 10706631
- Volume :
- 32
- Database :
- OpenAIRE
- Journal :
- Physics of Fluids
- Accession number :
- edsair.doi...........baf22278624f28a3b8a40cc6c9eefd40