Prof. Dimos Poulikakos
Laboratory of Thermodynamics in Emerging Technologies (LTNT)
Department of Mechanical and Process Engineering;
Director joint IBM-ETH Zurich Nanoscale Exploratory Technologies Laboratory (NETL)
Local: Centro de Tecnologia, Bloco G, sala 205
In his lecture novel concepts for high performance ultrathin manifold microchannel heat sinks and working fluids (emulsions and nanofluids) for electronics and other applications will be presented. The norm of minimizing the ratio of heat removed divided by the corresponding needed pumping power is employed to rate the heat sinks. For a volumetric flow rate of 1.3 l/min we demonstrated a minimal pressure drop of 0.22 bar on a 2X2 cm2 electrically hated chip. This allows for cooling power densities of more than 700 W/cm2 for a maximum temperature difference between the chip and the fluid inlet of 65 K. The total height of the heat sink did not exceed 1.5 mm. Furthermore, we will discuss the influence of elevated fluid inlet temperatures, allowing possible reuse of the thermal energy, and demonstrate an enhancement of the heat sink cooling efficiency of more than 40% for a temperature rise of 50 K. With reference to working fluids, both nanofluids and segmented liquid–liquid emulsions are studied. It is demonstrated that segmented liquid-liquid coolants yield significant Nusselt number enhancement in microchannel heat sinks compared to that obtained using single phase liquid cooling. Laser Induced Fluorescence (LIF) is employed to measure the temperature of the coolant, and micro-PIV is used to determine the velocity field. It is also demonstrated that the performance of nanofluids can be predicted by classical convection correlations using the correct thermophysical properties of the nanofluids, whereby no increase in the thermal conductivity of the nanofluids beyond that predicted by Maxwell’s theory is unequivocally demonstrated. The potential of the heat sink concepts above in terms of reuse of the thermal energy produced by supercomputer centers and solar cell installations in district heating or desalination processes will also be discussed.Professor Dimos Poulikakos holds the Chair of Thermodynamics at ETH Zurich, where in 1996 he founded the Laboratory of Thermodynamics in Emerging Technologies in the Institute of Energy Technology. From October 1999 to September 2001 he was also the Head of the Institute of Energy Technology. From October 2001 to September 2003 he was associate head of research of the Department of Mechanical and Process Engineering at. He was a Member of the Research Commission of ETH (2001-2005) and the Vice Chair and then Chair of the Leonard Euler Center in Switzerland, the Swiss Branch of ERCOFTAC (2002-2005). He served as the Vice President of Research of ETH Zurich in the period 2005-2007. Currently, Professor Poulikakos is the ETH director of the IBM-ETH Zurich Nanoscale Exploratory Technologies Laboratory (NETL), a unique private-public partnership in nanotechnology at the interface of basic research and future oriented applications.
His current research is in the area of interfacial and transport phenomena and energy, in particular heat transfer, thermodynamics and related fluid dynamics in emerging technologies and materials including the physics at micro- and nanoscales, novel electronics nanostructuring and cooling for energy efficient high performance computing, surface driven micro- and nanoscale energy conversion and on transport phenomena in medical applications with special emphasis on the human body.
Professor Poulikakos has supervised to completion over 50 Doctoral dissertations to date. He has published over 300 research articles in top peer reviewed journals in areas such as heat transfer, fluid dynamics, nanotechnology, materials, applied physics and energy, as well as numerous articles in reviewed proceedings of professional conferences and a graduate level textbook on Conduction Heat Transfer (Prentice Hall, 1994). He has also edited and co-authored a special volume of Advances in Heat Transfer (1996), dedicated to transport phenomena in materials processing.
Among the awards and recognitions he has received for his contributions are the White House/NSF Presidential Young Investigator Award in 1985, the Pi Tau Sigma Gold Medal in 1986, the Society of Automotive Engineers Ralph R. Teetor Award in 1986, the University of Illinois Scholar Award in 1986 and the Reviewer of the Year Award for the ASME Journal of Heat Transfer in 1995. He is the recipient of the 2000 James Harry Potter Gold Medal of the American Society of Mechanical Engineers “for his outstanding contributions to thermodynamics and its applications in emerging technologies”. He was a Russell S. Springer Professor of the Mechanical Engineering Department of the University of California at Berkeley (2003) and the Hawkins Memorial Lecturer of Purdue University in 2004. He received the Heat Transfer Memorial Award for Science in 2003, from the American Society of Mechanical Engineers, "for outstanding and original research contributions to solidification, bio-fluid mechanics, porous structures and other areas of heat transfer science, and investigations into their application to new and emerging technologies." In 2008 he was a visiting Fellow at Oxford University and a distinguished visitor at the University of Tokyo. He is the recipient of the 2009 Nusselt-Reynolds Prize of the World Assembly of Heat Transfer and Thermodynamics conferences, for his scientific contributions.
He received the Dr.h.c. of the National Technical University of Athens in 2006. In 2008 he was elected to the Swiss National Academy of Engineering (Schweizerische Academie der Technischen Wissenschaften--SATW)
Professor Poulikakos has been a frequent keynote speaker in many conferences worldwide. He is the Editor in Chief of the Journal the Experimental Heat Transfer, and a member of the board of Editors of the Journal of Microscale and Nanoscale Thermophysical Engineering, the Journal of Porous Media, the International Journal of Thermal Sciences and the Intl. Journal of Heat and Mass Transfer. He was also an Editor of the Journal ACTA Mechanica since 2000-2005. He is the European Editor of the Intl. Journal of Transport Phenomena. He has served as an associate editor of the ASME Journal of Heat Transfer 1999-2002. He is a Fellow of ASME.