SUBJECT: Ph.D. Proposal Presentation
BY: Tongran Qin
TIME: Friday, December 13, 2013, 2:30 p.m.
PLACE: the Howey Physics building, W505
TITLE: Numerical Investigation of Buoyancy-thermocapillary Convection of Volatile Fluids in Confined and Sealed Geometries
COMMITTEE: Dr. Minami Yoda, Co-Chair (ME)
Dr. Roman Grigoriev, Co-Chair (Physics)
Dr. G. Paul Neitzel (ME)
Dr. Marc Smith (ME)
Dr. Mike Schatz (Physics)


Convection in a layer of fluid with a free surface due to a combination of thermocapillary stresses and buoyancy is a classic problem of fluid mechanics. Although this problem was studied previously as a model of crystal growth in microgravity environments, with the focus on liquid metals and, correspondingly, low values of the Prandtl number, more recently the motivation for studying this problem has shifted to higher Prandtl number fluids due to the increased demands on the performance of various cooling technologies. Many of the modern cooling technologies exploit the large latent heats associated with phase change at the free surface of volatile liquids, allowing compact devices to handle very high heat fluxes. Such cooling devices usually employ a sealed cavity with a liquid layer under its own vapor and contain in practice a small amount of noncondensable gases, such as air. Heating one end of the cavity, and cooling the other, establishes a horizontal temperature gradient that drives the flow. Although this is an extensively studied problem, our fundamental understanding of the associated thermal and mass transport remains limited.

The objectives of this study are:
1) to develop and employ a comprehensive, self-consistent numerical model for the buoyancy-thermocapillary convection in a confined, sealed geometry;
2) to validate this model using experimental results;
3) to use this model to identify how various physical effects impact heat and mass transfer.