Satish G. Kandlikar is a Distinguished Institute Professor and the Gleason Professor of Mechanical Engineering at Rochester Institute of Technology, where he is working since 1980. He received his Ph.D. degree from the IIT Bombay in 1975. He has worked extensively in the area of flow boiling, pool boiling, CHF phenomena at microscale, single-phase flow in microchannels, electronics cooling, water management in PEM fuel cells and breast cancer detection. He has published over 400 journal and conference papers. He is the recipient of the 2012 ASME Heat Transfer Memorial Award. His recent work on pool and flow boiling has provided a mechanistic understanding of the boiling phenomena at microscale and nanoscale produced enhancement structures dissipating exceptionally high heat fluxes along with very high heat transfer coefficients. He started the ASME International Conference on Nanochannels, Microchannels and Minichannels and has been its chair for ten years. He is also recipient of numerous awards, including 2008 Engineer of the Year Award, 1996 Eisenhart Outstanding Teaching Award and RIT Trustee’s Scholarship Award among others.

Invention is a key enabler of progress. It starts with the understanding of how things work, and it leads to finding new pathways for changing the paradigm. Innovation takes it a step further, makes it useful, and demonstrates practical feasibility of a new process or a device. As a case study, the underlying mechanisms in a high heat flux cooler that utilizes efficient boiling/condensation mechanisms have been identified and new techniques and mechanisms were invented, and through research and innovation, major strides have been made in improving its performance. The “traditional” boiling process illustrated by a tea kettle boiler has undergone major changes based on the new understanding of various heat transfer mechanisms that have been recently identified surrounding a bubble. Inventing and then innovating are the major steps in the journey of an idea from inception to implementation in real world devices. This journey is fascinating, and the researchers derive great joy in facilitating as well as undertaking this journey. Be a part of this experience!

Professor Yasuyuki TAKATA is a Specially-Appointed Professor and Professor Emeritus at International Institute for Carbon-Neutral Energy Research (I2CNER), Kyushu University. His research interests include two-phase flow and heat transfer and thermophysical properties of hydrogen at ultra-high pressure. He was the Presidents of Heat Transfer Society of Japan (HTSJ) from 2019 to 2020 and the Asian Union of Thermal Science and Engineering (AUTSE) from October 2020 to September 2022. He received numerous awards including the JSME Thermal Engineering Achievement Award, HTSJ Award for Scientific Contribution. He is a Council Member of the Science Council of Japan since October 2020.

It is of great importance for water spray cooling of hot steel to predict “quenching point” where rapid cooling occurs by the direct contact between liquid and hot surface. Despite a number of previous studies, the mechanism of onset of quenching has not yet been clearly understood. One of the reasons is due to the oxide layers formed on the hot surface. These oxide layers have non-uniform porous structure and low thermal conductivity and hence increase the quenching temperature. In the present study, we try to explain the quenching temperature based on the assumption of the transient heat conduction for a contact between two semi-finite bodies. We used several different artificial oxide layers and made a series of experiments on spray cooling and observation of single individual droplet impinging onto the hot oxide surfaces. As a result, the onset of quenching always seems to happen at the contact surface temperature of around 250°C regardless of the composition and thickness of the oxide layer.

John Thome is Prof. Emeritus EPFL, Technical Director of JJ Cooling Innovation in Lausanne, Switzerland with his PhD at Oxford University. He is the author of 5 books and Editor-in-Chief of the 16-volume Encyclopedia of Two-Phase Heat Transfer and Flow. He received: 2017 Nusselt-Reynolds Prize, IEEE 2019 Richard Chu ITHERM Award, ASME 2019 Allan Kraus Thermal Management Medal and 2010 ASME Heat Transfer Memorial Award. He is a long-time researcher and technology specialist in microscale and macroscale two-phase heat transfer and two-phase systems, pulsating heat pipes, loop thermosyphons and refrigeration systems. He is widely known for his flow pattern-based prediction methods for flow boiling, condensation and two-phase pressure drops, and numerous studies on multi-microchannel evaporators. He has developed numerous two-phase cooling technologies for electronics cooling covering a broad range of industries.

ABSTRACT

Passive two-phase cooling of electronics has been progressing with widespread use of wicked heat pipes and more recently vapor chambers. Two other passive two-phase devices emerging: Loop thermosyphons (LTSs) and Pulsating heat pipes (PHPs. Loop thermosyphon cold plates can handle much higher heat fluxes than simple vertical pipe thermosyphons, in which the working fluid in an LTS flows from its evaporator up a riser tube to the condenser and then its condensate flow down through a downcomer back to the inlet of the evaporator. LTS technologies are available for the cooling of individual datacenter CPUs as well as cooling of multiple heat sources in Edge micro-datacenters, telecom photonics transmitters and entire high power datacenter racks (including AI). Pulsating heat pipes are a recent addition to passive cooling technologies: PHPs create self-activated and self-induced oscillating two-phase flow, without any internal wick structure, in a microchannel serpentine loop that goes back-and-forth from its evaporator zone to its condenser zone. Both of these are gaining industrial traction for cooling of power electronics, 5G base stations, CPUs, etc. The talk will present and describe how LTSs and PHPs function and the keys to their performance and usage. Notably, when utilizing LTSs and PHPs, the thermal efficiency of electronics cooling attains the new goals for reducing electrical cooling power consumption, with PUEs as low as 1.017 in performance tests with air-cooled condensers (power consumed by the fan), and in several cases using natural convection to air from the condenser are able to take the PUE to 1.00, that is zero energy consumption (fan off) that are promising for electronics on standby or low/medium operation. Actual units/systems for a variety of industries will be described.

Dr. Chun Yang is a Full Professor in School of Mechanical and Aerospace Engineering at Nanyang Technological University (NTU). He obtained his B.Sc. degree from Tsinghua University, M. Eng degree from University of Science and Technology of China, and Ph.D. degree from University of Alberta. Prior to joining NTU in 1999, he had been with Syncrude Canada Ltd. - Edmonton Research Centre under NSERC Chair Programme in Oil Sands for three years. He is Editor/Associate Editor and on the Editorial/Advisory Boards for several journals. He is Fellow of both ASME and AUTSE, and won China Changjiang Distinguished Professorship.

ABSTRACT

The past two decades have seen fast development of microfluidics. Electrokinetic driven phenomena that employ DC or AC electric fields to pump, mixing/concentrate, split liquid buffers and to transport, separate, pattern particles/cells, enjoy numerous advantages such as no moving parts, ease of control, well integration with standard fabrication methods. In this talk, I will present both experimental and theoretical aspects of several linear and nonlinear electrokinetic phenomena: the micro-PIV characterizations of the electroosmotic flows with and without Joule heating effects, temperature gradient focusing, micromixing enhancement, generalized electrokinetic boundary conditions, and particle patterning with dielectrophoresis. Additionally, new development in electrokinetic energy generation will be discussed.

Dr. Wei Li, professor and Fellow ASME has published 200+ journal papers as the corresponding author in prestigious journals such as five ASME journals and Int. J. Heat Mass Tran. His research includes ex-perimental, numerical, and theoretical studies. His group leverages state-of-the-art micro/nanofabrication and synthesis, unique measurement and simulation, and model prediction capabilities to perform in-depth studies and enable mechanistic insights into complex fluidic and thermal transport processes. His three correlations on micro flow boiling have been adopted in "ASHRAE Handbook - Fundamentals" since 2012. He has served as Associate Editors for six SCI journals including four ASME journals in-cluding Journal of Electronic Packaging and Open Journal of Engineering.

ABSTRACT

Utilizing flow phase change requires fine manipulation of interfacial transport. Field synergy indicates the mechanism of single phase convective. Fundamental understanding during liquid-vapor flow phase change remains limited to date as it is generally challenging to characterize convective at the interface. Potential fluctuation presents potential oscillatory wave interface in the spatial and temporal dimensions as decided by the continuity equation. It is the origin of flow regime in two-phase flow and flow instability in general. The talk presents experimental and theoretical analyses on liquid-vapor flow interface development and its application in flow instability.

Deanna Lacoste is an associate professor of mechanical engineering at the King Abdullah University of Science and Engineering (KAUST), in Saudi Arabia. She graduated with a Ph.D. in combustion science from the University of Poitiers, France, in 2002. After eleven years with the French CNRS, at Centrale Supelec, in 2014 she joined KAUST. Since 2021, she has been an associate professor at the Clean Combustion Research Center, KAUST. She is an editorial board member of the Applications in Energy and Combustion Science journal, and an associate editor for the Proceedings of the Combustion Institute. Her research mainly focusses on plasma-assisted combustion, non-equilibrium plasma discharges at atmospheric pressure, control of flame dynamics, and detonation.

ABSTRACT

Energy conversion systems based on combustion are facing multiple challenges such as the arrival of new fuels, increasingly drastic pollutant regulations, and the pressure of extremely ambitious nationally determined contributions of the Paris Agreement. In this fast-evolving environment, control of combustion dynamics is becoming both more important and more difficult. Combustion processes are sensitive to the chemical composition of the medium, the thermodynamic conditions, and the flow. By changing any of these, it is possible to modify the combustion rate and to control the flame dynamics. Non-thermal plasma produced by electric discharges have chemical, thermal and transport effects that can be used to stabilize combustion. In this talk, I will present recent progress in control of flame dynamics by non-thermal plasma produced by nanosecond repetitively pulsed discharges, with a special focus on the importance of transport phenomena.

Professor Huasheng Wang is a Professor of Thermofluids Engineering in the School of Engineering and Materials Science at Queen Mary University of London. His recent research interests include enhanced heat transfer, condensation and flow boiling heat transfer in tubes and microchannels, Marangoni condensation, condensation and flow boiling heat transfer of low GWP refrigerants and zeotropic refrigerant mixtures and inverse heat transfer measurement. He is also focused on solid-state magnet-/electro-/baro-caloric refrigeration systems, heat pump heating systems, building energy efficiency and intelligent buildings.

ABSTRACT

An inverse method was proposed and implemented to measure local condensation heat transfer in microchannels. The temperatures in the test blocks are accurately measured by 100 thermocouples and the local heat flux and channel surface temperature along the channel are obtained using the inverse heat conduction method. Extensive experimental data have been obtained for condensation of FC72, R1233zd(E) and R456A in microchannels. The experimental data are compared with the theoretical predictions of Wang and Rose (2005) and empirical correlations.

Dr. Chia-Wei Chen is the general manager of Advanced Thermal Solutions at Supermicro Computer Inc. where he is working since 2020. He received his Ph.D. degree from the National Central University, Taiwan in 2011 with researches mainly on heat exchangers design and two-phase heat transfer. He is currently in response of the most advanced thermal solutions at Supermicro, including air cooling and liquid cooling solutions, especially on the heat transfer enhancement technologies on direct to chip liquid cooling and immersion cooling systems. The application scopes of his work are from traditional servers, edge servers, to AI servers, with the aims to achieve the SMC’s green computing goals.

ABSTRACT

As extremely high computing density is required for AI computation, the thermal design power (TDP) of CPUs and GPUs increased drastically in the past few years. The high TDP thermal solution became a critical technology for continuing development of high-performance ICs. Moreover, due to the global greening requirements, how to improve cooling efficiency and reduce the PUE of the data center is currently the most important issue for thermal solutions system design. In this talk, the recent efforts on the thermal enhancement technologies by Supermicro which from the directly to chip cooling solutions, cold plate optimization, to immersion cooling, and even though cooling water tower optimizations will be discussed. It is aimed to achieve the green computing goals by Supermicro with reducing overall data center power consumption by up to 40 %.

Dr. Liang-Han Chien received his B.S. degree from National Taiwan University in 1989. He obtained his M.S. and Ph. D. degree in Mechanical Engineering from the Pennsylvania State University in 1995. Currently, He is the Dean of the College of Mechanical and Electrical Engineering at the National Taipei University of Technology, Taipei, Taiwan. He also serves as a distinguished professor and the director of the Research Center of Energy Conservation in the Commercial, Residential, and Industrial Sectors at NTUT. His research interests include heat transfer, two-phase flow, boiling and condensation, electronics cooling, air conditioning, refrigeration, and energy conservation.

ABSTRACT

This speech discusses heat transfer research on various low GWP refrigerants. The results of heat transfer experimental studies of boiling and condensation heat transfer of various fluids, including R1234yf, R452B, R513A, Hydrocarbons, and their mixtures will be presented and discussed. The pool boiling test results of mixtures showed that the heat transfer coefficient deteriorated as the temperature glides and the vapor-liquid fraction difference became more prominent. The theoretical analysis of the mixtures is evaluated against experimental data. Experimental data of several Low GWP refrigerants tested in a water chiller and applicability are also discussed.