Collaborative Research: Fundamental Studies of Vapor-Liquid Interfaces with Phase Change in Microdevices

University Of California-Santa Barbara, Santa Barbara CA

Investigators

Abstract

ABSTRACT PROPOSAL NO.: CTS-0245396, CTS-0244676 PROPOSAL TYPE: INVESTIGATOR INITIATED (COLLABORATIVE) PRINCIPAL INVESTIGATORS: GEORGE M. HOMSY, VLADIMIR S. AJAEV INSTITUTION: U.C. SANTA BARBARA, SOUTHERN METHODIST UNIVERSITY COLLABORATIVE RESEARCH: FUNDAMENTAL STUDIES OF VAPOR-LIQUID INTERFACES WITH PHASE CHANGE IN MICRODEVICES The proposal addresses fundamental issues of fluid mechanics and heat transport in evaporation and condensation at vapor-liquid interfaces in constrained geometries. Combined theoretical/computational and experimental studies of a range of phenomena are proposed which will allow insight into the underlying mechanisms common to many different applications such as micro heat pipes, microelectromechanical systems (MEMS), and optical switches. This is a collaboration between engineering scientists at UCSB and applied mathematicians at SMU. Two closely related sets of problems are addressed. The first involves studies of three-dimensional steady interfacial configurations in complex geometries in which evaporation is balanced by condensation in the colder regions. Challenges here include solving nonlinear free-boundary problems where fluid flow and heat transfer are coupled together. Experiments in which simultaneous measurements of heat flux, temperature distributions, and vapor bubble configurations will be conducted. The second set of problems to be addressed involves unsteady motion of constrained interfaces. The proposed research has broad technological impact. This includes improvements in the design of heat pipes for effective cooling of electronic components, and underpinnings for the development of a new type of an optical switching device, which can lead to a dramatic increase in the speed of communication networks. The project will promote learning through research and interdisciplinary scientific collaborations. Graduate students will gain valuable research experience and expand their knowledge beyond their field of study by interacting with both PIs and with students of different backgrounds and perspectives. Outreach is provided to high school students during the summer months as part of the organized UCSB program for prospective engineering and science majors. To further increase the educational value of the project, the results will be incorporated into an educational module as part of Volume 2 of Multimedia Fluid Mechanics, educational software. This project is being funded by the Fluid Dynamics and Hydraulics, Interfacial Transport and Thermodynamics and Thermal Transport and Thermal Processing Programs in the Division of Chemical and Transport Systems.