PHYSICS SEMINAR
Wednesday,
September 11, 2002
Willet Science Center 101
“Thin-film analysis of the return flow and resulting interface shape of a
thermocapillary-driven nonwetting droplet”
Abstract: A liquid droplet coating a flat, solid surface maintains separation from an
opposing solid boundary with thermocapillary-driven nonwetting. Shear stress at the droplet interface draws the surrounding gas between the droplet and
solid boundary producing a lubricating gas layer. The necessary return flow of the gas forces a redirection at the centerline of the droplet resulting
in a deformed droplet shape. An asymptotic analysis considers the two-dimensional, coupled liquid/gas flow field in an attempt to determine
the droplet shape and identify the influential physics. A two-dimensional core flow is found in the droplet and gas layer with a transition boundary
layer existing only in the gas flow near the edge of the droplet. Choices and limitations of the
asymptotic analysis and resulting first-order flow fields including interface shape will be presented. This work was supported
by a NASA/ASEE Summer Faculty Fellowship, Glenn Research Center, Microgravity Fluid Physics Branch, Cleveland, OH.
Please
join us for light refreshments at 4:15.