Postdoctoral work

Current position - NIST-ARRA postdoctoral fellow at University of Maryland College Park

" Bubble motion and size variation during thermal migration with phase change "
An analysis of the motion of a spherical bubble in a two-phase, single component system with a vertical linear temperature gradient is presented. The model
for the migration of an immiscible bubble under the effects of buoyancy and thermocapillarity considered by Young, Goldstein and Block is modified to allow for
phase change at the bubble surface. These changes allow the possibility of both translation of the bubble in the vertical direction and the change of bubble radius with time.
Depending on the material parameters, 
the effects of latent heat generation can overwhelm the thermocapillary and buoyancy effects, that govern the migration of an immiscible bubble, and drive the motion of the bubble. For a water-steam system conditions are determined for a stationary bubble in which the effects of buoyancy and thermal migration are balanced. The
linear stability of the bubble is considered, and conditions are determined that correspond to small-amplitude oscillations of the position and radius of the bubble as were observed by Hardy for an air-silicone oil system. A weakly nonlinear analysis of the solution in the vicinity of the unstable solution is performed, and the results are compared with a numerical solution of the nonlinear
equations.



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