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From antinode clusters to node clusters:. The concentration dependent transition of floaters on a standing Faraday wave. Ceyda Sanli , Detlef Lohse , and Devaraj van der Meer. Physics of Fluids, University of Twente , The Netherlands. Observation:. 5 mm.
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From antinode clusters to node clusters: The concentration dependent transition of floaters on a standing Faraday wave CeydaSanli, DetlefLohse, and Devaraj van der Meer Physics of Fluids, University of Twente, The Netherlands.
Observation: 5 mm antinode clusters f=19 Hz a=0.1mm adding more floaters 5 mm node clusters f=20 Hz a=0.35 mm • Ref: C. Sanli, D. Lohse, and D. van der Meer, arXiv: 1202.0051
Set-up: • Control Parameters: • D = floater size • θ=wetting angle • a= amplitude • f= frequency • h= depth of water • ϕ = concentration a, f shaker shaker ϕ= Area / Area floater total
From antinode clusters to node clusters: • Why the antinode clusters at low ɸ ? • Why the node clusters at high ɸ ?
Why the antinode clusters at low ɸ ? • Drift force*: • The drift force is always towards the antinodes for our floaters. • The drift force is a single floater force. * G. Falkovichet. al., Nature (2005).
Why the antinode clusters at low ɸ ? • Analogy with a static case: • bubble case • On a static curved interface: • heavy particles goes to a local minimum • heavy particle • case
Why the antinode clusters at low ɸ ? • Wave elevator: • Drift force*: • The drift force is always towards the antinodes for our floaters. • The drift force is a single floater force. t < T/2 t > T/2 * G. Falkovichet. al., Nature (2005). • T is the standing wave period.
Experiment • Correlation number c: antinodes nodes
Experiment I II III
From antinode clusters to node clusters: • Why the antinode clusters at low ɸ ? • drift force • Why the node clusters at high ɸ ? • look at the experiment more carefully
From antinode clusters to node clusters: 10 mm 10 mm antinode clusters at low ɸ node clusters at high ɸ breathing non-breathing
Attractive capillary interaction: air water • r(t) increases & decreases at the breathing antinode clusters. • r(t) is almost constant at the non-breathing node clusters.
Energy approach: • We calculate the drift and capillary energies based on designed clusters: • antinode cluster: • node cluster:
Energy approach: Observed and designed clusters • The inset bars indicate a length scale of 5 mm.
Energy approach: • E is the sum of the drift and capillary energies. • σ : surface tension • l : capillary length c • ΔE = E - E . antinode node • N : number of floaters
Comparison: • Experiment • Energy approach
Energy approach in detail: • E:capillary energy • σ : surface tension c • E : drift energy • l : capillary length d c • N : number of floaters
Conclusion: • The dynamics of the floaters is highly influenced by the floater concentration ϕ: • low ϕantinode clusters • high ϕ node clusters • Potential energy estimation of the designed clusters presents good agreement with the experiment both qualitatively and quantitatively. • Energy approach shows that the drift with breathing is the reason behind the node clusters at high ϕ.
Recent work: Macroscopic spheres on capillary Faraday waves • Dynamic heterogeneity and dynamic criticality : a=0.1 mm f=250 Hz ɸ=0.633 2 mm • 4 timesslowerthanreal time. • Ref: C. Sanli, K. Saitoh, S. Luding, and D. van der Meer, arXiv: 1309.3804