Nonlinear hydrodynamic effects induced by Rayleigh surface acoustic wave in sessile droplets - Alghane et al 2012.pdf (981.33 kB)
Nonlinear hydrodynamic effects induced by Rayleigh surface acoustic wave in sessile droplets
journal contribution
posted on 2020-07-10, 15:10 authored by M Alghane, BX Chen, YQ Fu, Y Li, MPY Desmulliez, Mazher MohammedMazher Mohammed, AJ WaltonWe report an experimental and numerical characterization of three-dimensional acoustic streaming behavior in small droplets of volumes (1-30 μl) induced by surface acoustic wave (SAW). We provide a quantitative evidence of the existence of strong nonlinear nature of the flow inertia in this SAW-driven flow over a range of the newly defined acoustic parameter F{NA}=Fλ/(σ/R_{d})≥0.01, which is a measure of the strength of the acoustic force to surface tension, where F is the acoustic body force, λ is the SAW wavelength, σ is the surface tension, and R{d} is the droplet radius. In contrast to the widely used Stokes model of acoustic streaming, which generally ignores such a nonlinearity, we identify that the full Navier-Stokes equation must be applied to avoid errors up to 93% between the computed streaming velocities and those from experiments as in the nonlinear case. We suggest that the Stokes model is valid only for very small acoustic power of ≤1 μW (F{NA}<0.002). Furthermore, we demonstrate that the increase of F{NA} above 0.45 induces not only internal streaming, but also the deformation of droplets.
Funding
Innovative electronic Manufacturing Research Center (IeMRC) through the EPSRC funded flagship project SMART MICROSYSTEMS (FS/01/02/10), the Carnegie Trust Funding, the Royal Society of London (Research Grant No. RG090609), and the Royal Society of Edinburgh.
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School
- Design
Published in
Physical Review EVolume
86Issue
5Publisher
American Physical Society (APS)Version
- VoR (Version of Record)
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© American Physical SocietyPublisher statement
This paper was published in the journal Physical Review E and is available at https://doi.org/10.1103/PhysRevE.86.056304.Publication date
2012-11-09Copyright date
2012ISSN
1539-3755eISSN
1550-2376Publisher version
Language
- en
Depositor
Dr Mazher Mohammed. Deposit date: 8 July 2020Article number
056304Usage metrics
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