Abstract
Faraday surface instability measurements of the critical acceleration, ac, and wave number, kc, for standing surface waves on a tetracosanol (C24H50) melt exhibit abrupt changes at Ts=54°C, â4°C above the bulk freezing temperature. The measured variations of ac and kc vs temperature and driving frequency are accounted for quantitatively by a hydrodynamic model, revealing a change from a free-slip surface flow, generic for a free liquid surface (T>Ts), to a surface-pinned, no-slip flow, characteristic of a flow near a wetted solid wall (T<Ts). The change at Ts is traced to the onset of surface freezing, where the steep velocity gradient in the surface-pinned flow significantly increases the viscous dissipation near the surface.
Original language | English |
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Article number | 184504 |
Journal | Physical Review Letters |
Volume | 94 |
Issue number | 18 |
DOIs | |
State | Published - 13 May 2005 |