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Microchannel Flow Boiling of CO2: Applications to 2D and 3D Detector Cooling

Abstract: Flow boiling of CO2 is a very promising cooling process for future high energy physics particle detectors, including future 3D stacks. In the lecture, the highlights of my ongoing two-phase flow boiling research in microchannels will presented, illustrated by two-phase flow videos in single channels and multi-microchannel evaporators, including some CO2 videos. In particular, the important aspects of microchannel flow boiling in microchannels will be discussed and also the "weak points" of our current prediction methods (and what we are doing to improve them). A brief overview of our CMOSAIC project on two-phase cooling of future 3-dimensional computer chips in collaboration with IBM (stacks of processors cooled internally by interlayer microchannels) will be presented and used as an example of possible future directions/discussion of 2D and 3D detectors.
Speaker: John R. Thome - Swiss Federal Institute of Technology in Lausanne (EPFL), Switzerland
Speaker Bio: John R. Thome is Professor of Heat and Mass Transfer at the Swiss Federal Institute of Technology in Lausanne (EPFL), Switzerland since 1998, where his primary interests of research are two-phase flow and heat transfer, covering both macro-scale and micro-scale heat transfer and also enhanced heat transfer. Recently, his work has primarily focused on two-phase flow pattern based heat transfer and pressure drop models for microscale evaporating flows and the development of multi-microchannel evaporators for electronics cooling. In particular, he has developed such models for evaporation of CO2 in small channels. Prof. Thome is director of the Laboratory of Heat and Mass Transfer at the EPFL with a PhD and post-doc research staff of about 18-20 and is also Director of the Doctoral School in Energy. He received his Ph.D. at Oxford University, England in 1978 and was formerly a professor at Michigan State University and then from 1984 to 1998 he set up his own international engineering consulting company. He is the author of four books: Enhanced Boiling Heat Transfer (1990), Convective Boiling and Condensation, 3rd Edition (1994), Wolverine Engineering Databook III (2004) and Nucleate Boiling on Micro-Structured Surfaces (2008). He received the ASME Heat Transfer Division's Best Paper Award in 1998 for a 3-part paper on two-phase flow and flow boiling heat transfer published in the Journal of Heat Transfer. Prof. Thome received the UK Institute of Refrigerationís J.E. Hall Gold Medal in 2008 for his extensive work in the field of microscale refrigeration heat transfer and the 2010 ASME Heat Transfer Memorial Award for his work on flow pattern based heat transfer models for macro and micro-scale flows. He has published over 130 journal papers since joining the EPFL in 1998. He is the PI of the Swiss National Science Nano-Tera consortium project CMOSAIC, which is studying single- and two-phase cooling, thermal management and manufacturing of future 3D-IC computer chips with channel sizes as small as 50microns. He collaborates with CERN on CO2 flow boiling for cooling of future particle detectors. He is the Director of the European ERCOFTAC Coordination Center (European Research Community On Flow, Turbulence And Combustion) with about 180 affiliated universities, research centers and industrial companies.
Poster Link: Poster