PITA FY2014 Projects

Heat Transfer Enhancement in Nanoscale Film Evaporation

PI:Jonathan A. Malen, Mechanical Engineering
Alan J. H. McGaughey, Mechanical Engineering

University:Carnegie Mellon University

Co-PI(s):S. C. Yao, Mechanical Engineering

Industry Affiliate(s):Advanced Cooling Technologies

Summary:Our objective is to experimentally measure the evaporative heat transfer rate in 10-100 nm thick H2O liquid films using thermoreflectance-based measurements. New robust cooling concepts are required to address high heat loads in contemporary electronics. Ultra-high heat transfer rates have been predicted for thin film evaporation due to a reduction of the vaporization barrier that occurs for sub-100nm films. So far, experimental observations have been attributed to meniscus regions in porous structures, but their complicated geometries do not allow for probing the details of thermal transport and a development of fundamental understanding of the thin film evaporation process. We will isolate the unique physics of thin film evaporation with novel experimental techniques: (i) the use of surface micropatterning to “pin” the film thicknesses, and (ii) the application of thermoreflectance techniques, rather than conventional infrared imaging, to more accurately extract information about the evaporative heat transfer resistances. Advanced Cooling Technologies (ACT), our industrial collaborator, will translate scientific findings at CMU, into the next generation of heat pipe technologies.