Wetting and Phase Change Phenomena on Micro and Nanostructures for Enhanced Heat Transfer

Department of Mechanical Engineering & Materials Science Seminar

Wetting and Phase Change Phenomena on Micro and Nanostructures for Enhanced Heat Transfer
Yangying Zhu
Department of Mechanical Engineering
Massachusetts Institute for Technology

Abstract: Thermal management is a significant challenge in many electronic, energy, space and defense systems due to the increasing power density and heat generation rate. Improving the thermal performance of these systems requires fundamental understanding of the heat and fluid transport at the micro/nano scale through experiment and modeling, as well as the capability to nanoengineer surfaces and materials to control these transport processes. In this talk, I will provide a few examples of how we leverage micro scale manipulation capabilities to develop advanced thermal management solutions. While most micro and nanostructured materials are static, we developed dynamically tunable magnetic microstructures with an instantaneous response and large tunable range, and demonstrated real-time manipulation of fluid spreading, drag and optical transmittance. We also integrated microstructures into microchannel heat sinks and show that surface structures can increase flow stability and significantly enhance heat dissipation capability via capillary wicking. In addition to these experimental efforts, we provided quantitative understanding of the role of micro/nanostructures by developing a numerical modeling framework to optimize evaporation in wicking structures, where a quantitative understanding has been lacking due to the coupling of fluid flow and liquid-vapor interface. These nanoengineering approaches promise to address many of the pressing challenges in next generation thermal systems.

Host: Udo Schwarz
Monday, January 30, 2017
Mason Lab 107 2:30pm - 3:30pm
Refreshments 2:15pm