000014538 001__ 14538
000014538 005__ 20161115100154.0
000014538 04107 $$aeng
000014538 046__ $$k2016-08-21
000014538 100__ $$aLohse, Detlef
000014538 24500 $$aRole of natural convection in the dissolution of sessile droplets

000014538 24630 $$n24.$$p24th International Congress of Theoretical and Applied Mechanics - Book of Papers
000014538 260__ $$bInternational Union of Theoretical and Applied Mechanics, 2016
000014538 506__ $$arestricted
000014538 520__ $$2eng$$aThe dissolution process of small (initial (equivalent) radius R0 < 1 mm) long-chain alcohol (of various types) sessile droplets in water is studied, disentangling diffusive and convective contributions. The latter can arise for high solubilities of the alcohol, as the density of the alcohol-water mixture is then considerably less as that of pure water, giving rise to buoyancy driven convection. The convective flow around the droplets is measured, using micro-particle image velocimetry (uPIV) and the schlieren technique. When non-dimensionalizing the system, we find a universal Sh N Ral/4 scaling relation for all alcohols (of different solubilities) and all droplets in the convective regime. Here Sh is the Sherwood number (dimensionless mass flux) and Ra the Rayleigh number (dimensionless density difference between clean and alcohol-saturated water). This scaling implies the scaling relation Tc 0( Fig/4 of the convective dissolution time Tc, which is found to agree with experimental data. We show that in the convective regime the plume Reynolds number (the dimensionless velocity) of the detaching alcohol-saturated plume follows Rep N ScilRa5/8, which is confirmed by the uPIV data. Here, Sc is the Schmidt number. The convective regime exists when Ra > Rat, where Ra, : 12 is the transition Ra-number as extracted from the data. For Ra S Rat and smaller, convective transport is progressively overtaken by diffusion and the above scaling relations break down.

000014538 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000014538 653__ $$a

000014538 7112_ $$a24th International Congress of Theoretical and Applied Mechanics$$cMontreal (CA)$$d2016-08-21 / 2016-08-26$$gICTAM2016
000014538 720__ $$aLohse, Detlef
000014538 8560_ $$ffischerc@itam.cas.cz
000014538 8564_ $$s197200$$uhttps://invenio.itam.cas.cz/record/14538/files/TS.FM06-3.04.pdf$$yOriginal version of the author's contribution as presented on CD,  page 804, code TS.FM06-3.04
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000014538 962__ $$r13812
000014538 980__ $$aPAPER