Nonlinear oscillations of pendant drops
- Chemical Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6224 (United States)
Whereas oscillations of [ital free] drops have been scrutinized for over a century, oscillations of [ital supported] ([ital pendant] or [ital sessile]) drops have only received limited attention to date. Here, the focus is on the axisymmetric, free oscillations of arbitrary amplitude of a viscous liquid drop of fixed volume [ital V] that is pendant from a solid rod of radius [ital R] and is surrounded by a dynamically inactive ambient gas. This nonlinear free boundary problem is solved by a method of lines using Galerkin/finite element analysis for discretization in space and an implicit, adaptive finite difference technique for discretization in time. The dynamics of such nonlinear oscillations are governed by four dimensionless groups: (1) a Reynolds number Re, (2) a gravitational Bond number [ital G], (3) dimensionless drop volume [ital V]/[ital R][sup 3] or some other measure of drop size, and (4) a measure of initial drop deformation [ital a]/[ital b]. The change in frequency [Delta][omega] of pendant drops with increasing initial deformation is drop size dependent. As the average linear size of pendant drops characterized by [ital V][sup 1/3] becomes large compared to the rod radius, [ital V][sup 1/3]/[ital R][much gt]1, [Delta][omega] falls as [ital a]/[ital b] rises, in accordance with results for free drops. The dynamics of very small drops, i.e., ones for which [ital V][sup 1/3]/[ital R][much lt]1, however, are profoundly affected by the presence of the solid rod. For such small drops, [Delta][omega] rises as [ital a]/[ital b] rises, a remarkable fact. The results show that for drops of a given size, the frequency is insignificantly affected by viscosity over a wide of range of Reynolds numbers. However, when Re falls below a critical value, the nature of drop motion changes from underdamped oscillations to an aperiodic return to the rest state (Abstract Truncated)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 7143128
- Journal Information:
- Physics of Fluids; (United States), Vol. 6:9; ISSN 1070-6631
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
DROPLETS
OSCILLATIONS
FINITE ELEMENT METHOD
GALERKIN-PETROV METHOD
LIQUIDS
REYNOLDS NUMBER
SURFACE TENSION
TRANSIENTS
CALCULATION METHODS
FLUIDS
ITERATIVE METHODS
NUMERICAL SOLUTION
PARTICLES
SURFACE PROPERTIES
661300* - Other Aspects of Physical Science- (1992-)