TopKeynote speakers

Keynote speakers

Gang Chen (Massachusetts Institute of Technology, USA)

Presentation title: Nanoscale Heat Transfer for Energy Applications

Abstract: Nanotechnology focuses on small scale effects. Energy is a global issue. Despite such disparities, there is a growing awareness that nanoscience and nanotechnology can have a profound impact on energy generation, storage, and utilization by exploiting the significant differences of energy states and transport between nanostructures and macrostructures. In this talk, I will discuss a few examples exploiting nanoscale heat transfer effects for energy conversion and utilization, including thermoelectric energy conversion and photovoltaics, and advanced materials for efficient utilization of thermal energy.

Biography:Dr. Gang Chen is currently the Carl Richard Soderberg Professor of Power Engineering at Massachusetts Institute of Technology. He obtained his Ph.D. degree from UC Berkeley in 1993 working under then Chancellor Chang-Lin Tien. He was a faculty member at Duke University (1993-1997), University of California at Los Angeles (1997-2001), before joining MIT in 2001. He is a recipient of the NSF Young Investigator Award, the ASME Heat Transfer Memorial Award, the R&D100 Award, and the MIT McDonald Award for Excellences in Mentoring and Advising. He is a member of the US National Academy of Engineering, a Guggenheim Fellow, an AAAS Fellow, and an ASME Fellow. He serves as the director of Solid-State Solar-Thermal Energy Conversion Center (S3TEC), a DOE Energy Frontier Research Center. He has published extensively in the area of nanoscale energy transport and conversion and nanoscale heat transfer.

Prof. Chen

Takemi Chikahisa (Hokkaido University, Japan)

Presentation title: Microscopic Observation of Water Transport Phenomena in PEM Fuel Cell using Freezing Method

Abstract: In Polymer electrolyte membrane fuel cells (PEMFC), generated water transports through variety scales of pores, ranging from nanometer scale in catalyst layer through micrometer scale of gas diffusion layers (GDL) to millimeter scale of gas channels. The water transport phenomena through the layers are essential for cell performance but are quite complex because of two phase flow in the different scales of pores. The keynote speaker investigated water distribution in GDL and the catalyst layer (CL) at the cathode side with a freezing method developed by his group. The state of the liquid water distribution in the normal temperature operation was frozen by cooling to –30 °C, then the cell was disassembled into component parts in the thermostatic chamber, and the surface and the cross section of the layers were observed with an optical microscope and a CRYO-SEM. The result showed that micro-porous layer (MPL) has a function of preventing accumulation of water on the surface of CL and supressing water flooding. Comparison between the experiment and an analysis showed that lower thermal conductivity and smaller pore size of MPL compared to GDL promotes water transport in vapor phase through MPL, and this contributes to the separation of liquid water location apart from CL surface. The keynote speech will also present some examples of different water behaviors in cold start depending on temperatures.

Biography:Dr. Takemi Chikahisa is currently Professor of Hokkaido University. He obtained his Ph.D. degree from Hokkaido Univerisity in 1982. He was a Jr. Associate Professor at Hokkaido University(1982-1984), and Associate Professor(1984-2003). He was a researcher of internal combustion engines, and proposed a similarity theory of combustion in diesel engines. Recently he has been working on the water transport behavior in PEM fuel cell and trying to find optimal design structure of gas channel and gas diffusion layer (GDL). He is also interested in the analysis of effective strategy of reducing CO2 emission from a country with keeping employment by using MARKAL model.

Prof. Chikahisa

Zeng-Yuan Guo (Tsinghua University, China)

Presentation title: Entropy and Entransy

Abstract: This presentation is divided in four parts with the first one dealing with the limitation of entropy generation as a measure of the irreversibility of heat transfer process. In the second part a new physical quantity, entransy, is introduced by induction and deduction, which possesses both the nature of energy and the ability of heat transfer. Its dissipation represents the irreversibility of heat transfer process not inside a thermodynamic cycle. The third part addresses the minimum principle of entransy dissipation based thermal resistance for the optimization of conduction, convection or radiation. This principle differs from the minimum principle of entropy production for the thermodynamic optimization of heat transfer. Finally, we will revisit the quantity, entropy, and clarify its macroscopic significance from the viewpoint of entransy.

Biography:Prof. Zeng-Yuan Guo is Professor of Department of Engineering Mechanics at Tsinghua University, Member of Chinese Academy of Sciences, and International Professor of Mechanical Engineering at Michigan State University, USA. Prof. Guo is Fellow of American Society of Mechanical Engineers. He serves as Member of Editorial Board for International Journal of Multiphase Flow, Nanoscale and Microscale Thermalphysical Enigeering, Journal of Enhanced Heat Transfer, Frontiers in Heat and Mass Transfer and Science in China-Series E. Prof. Zeng-Yuan Guo received the 2007 & 2011 National Natural Science Awards of China, 2009 Most Cited Article Award of International Journal of Heat and Mass Transfer, ICMM2005 Lifetime Contribution Award in the Field of Microscale Heat and Mass Transfer, and the JSME 2006 Thermal Engineering Award for International Activity. His current research interests cover thermomass theory and its applications, micro/nano-scale heat transfer, heat transfer enhancement, etc. He has published four monographs and over three hundred papers.

Prof. Guo

Sung Jin Kim (Korea Advanced Inst. of Sci. and Tech., Korea)

Presentation title: Recent Advances in Impinging Jets

Abstract: A single jet or an array of jets, impinging normally on a surface, is widely used in many engineering applications because very high rates of heating, cooling, or drying can be achieved. Major industrial applications of the impinging jet include cooling of turbine blades and electronic components, annealing of metal sheets, drying of textile and paper products, and deicing of aircraft systems.

This talk is intended to give an overview of the fundamentals of impinging jets together with recent advances achieved at the Applied Heat Transfer Lab of KAIST. Specifically, some interesting results on microscopic and macroscopic jets impinging onto a flat surface or a heat sink will be presented. The hydraulic jump, a phenomenon that includes the sudden deceleration of liquid along the wall and affects heat transfer, will be discussed along with the results of hydraulic jump location prediction. Next, a comparison between single-phase and two-phase impinging jets will be shown together with the benefits of using a two-phase impinging jet. Finally, a simple imaging technique based on the hydrodynamics of an impinging jet, the Scanning Flow Impedance Microscope (SFIM), will be presented. The SFIM can be used to image the surface topography of a specimen, and has advantages over conventional forms of microscopy, such as the electron microscope.

Biography: Dr. Sung Jin Kim is a Full Professor in the Department of Mechanical Engineering at the Korea Advanced Institute of Science and Technology (KAIST). He received a Ph.D. degree in Mechanical Engineering from Ohio State University in 1989. He then went on to work as a group leader for the Thermal Engineering Center at IBM’s Tucson Laboratory for 7 and 1/2 years, until he took a teaching position at KAIST. Dr. Kim specializes in cooling technology. Specific areas of expertise and research interests include the optimal design of heat sinks, conventional and next-generation heat pipes, and both gas and liquid impinging jets. He is an ASME Fellow and has received the Scientific Achievement Award from KSME, five Excellent Teaching Awards from KAIST, two Invention Achievement Awards and five Author Recognition Awards from IBM, holds 7 patents, and has published 150 papers in the area of convective heat transfer. He has also edited a book entitled Air Cooling Technology for Electronic Equipment. He served as a Thermal Engineering Division Chair of KSME in 2011.

Prof. Kim

Mamoru Tanahashi (Tokyo Institute of Technology, Japan)

Presentation title: Multi-Dimensional/Multi-Variable Laser Diagnostics and DNS in Turbulent Combustion Research

Abstract: Detailed understanding of turbulent combustion phenomena is very important to develop high efficiency combustors which contribute to resolve global environmental issues. Since turbulent combustion involves strong interactions between turbulence and combustion reactions, highly-sophisticated measurement techniques and numerical simulations both for fluid motion and flames are required. In this talk, current state and perspective both of laser diagnostics and direct numerical simulations (DNS) of turbulent combustion are provided. For fluid velocity measurement, state-in-art stereoscopic particle image velocimetry (PIV) is shown and its importance in turbulent combustion researches is discussed. For flame measurements, advanced planar laser induced fluorescence (PLIF) techniques such as simultaneous multi-radicals high-speed PLIF and stereoscopic PIV are presented and investigations on local flame structure, global/local flame dynamics and three-dimensional flame structures are surveyed. As for DNS of turbulent combustion, after presenting recent progress in combustion DNS, possibility of perfect simulations of IC engine is shown based on the perspective of DNS of turbulent combustion.

Biography: Dr. Mamoru Tanahashi is currently Professor of Department of Mechanical and Aerospace Engineering at Tokyo Institute of Technology. He obtained his Dr. Eng. degree from Tokyo Institute of Technology in 1996. He was Research Associate at Tokyo Institute of Technology (1992-2000) and Associate Professor (2000-2012). His research interests include numerical, experimental and theoretical studies of turbulence structure, turbulence control, turbulent combustion mechanism, combustion control, turbulent heat & mass transfer and aero acoustics. He has published more than 90 refereed journal papers and more than 18 review papers. He has won 13 awards from different institutions including the Young Scientists' Prize, the commendation for science and technology by MEXT, Japan(2006). His research has been accepted for Cabinet Office/JSPS “Funding Program for Next Generation World-Leading Researchers (NEXT program)” initiated by the Council for Science and Technology Policy, Japan.

Prof. Tanahashi

Peng Zhang (Shanghai Jiao Tong University, China)

Presentation title: Thermofluidic phenomena in the heat transfer of supercritical fluid: thermoacoustic wave, piston effect and thermal convection

Abstract: At the liquid-gas critical point, fluid properties exhibit dramatic behaviors. The thermal diffusivity goes to zero, and both the isothermal compressibility and isobaric thermal expansion coefficient violently diverge. Global thermal homogenization in a confined near-critical fluid is realized predominantly via the thermoacoustically-based piston effect. The expanding thermal boundary layer, acting like a moving piston, compresses the remainder of the fluid and raises temperature and pressure in an extremely efficient manner. We carried out a comprehensive study of heat transport in proximity of the critical point across different timescales.

On the short acoustic timescale, the enhancement of energy transfer is mostly attributed to thermoacoustic waves emitted from the heated boundary. By means of numerical simulation, we examined various internal and external factors in thermoacoustic wave generation, propagation, and reflection patterns. The distance to the critical point is shown to affect sound emission in a subtle and transient way. As the distance is further reduced, a new viscous regime is entered with the emergence of diverging bulk viscosity, which might lead to a secondary piston effect. Also, the rapidity of thermal perturbations is found to have a significant impact on the wave dynamics, resulting in two essentially different wave motions.

On the long diffusion timescale, the particular thermomechanical equilibrium under the piston effect is known to give rise to complications with the initiation of hydrodynamic instability under terrestrial conditions. The governing Navier-Stokes equations were numerical solved for a near-critical fluid in a 2D rectangular enclosure heated from below. After making corrections for non-Boussinesq effects, simple scaling relations were found of various properties of Rayleigh-Bénard convection. The asymptotic limitations in the Rayleigh-Nusselt relation correspond to vastly different thermogravitational flow patterns. By the use of laser holographic interferometry, we observed the transition from the piston effect-dominated temperature field to full-blown convection in supercritical nitrogen.

Biography:Peng Zhang was born on 9th May, 1973. He graduated from Shanghai Jiao Tong University in 1995 with a Bachelor degree, and he completed his Ph.D. study in 1999 from the same university. He then joined Institute of Refrigeration and Cryogenics at Shanghai Jiao Tong University as an Assistant Professor. He was ever the JSPS Postdoctoral Research Fellow in 2002 and spent two years at University of Tsukuba in Japan to conduct the research on heat transfer of superfluid helium. He is now the full Professor in Mechanical Engineering at Shanghai Jiao Tong University.

Dr. Peng Zhang’s research interests are thermal and fluidic phenomena at low temperatures, energy saving through thermal/cold storage. He is the principle investigator of many projects from National Natural Science Foundation of China, Ministry of Education, etc. He has coauthored more than 100 referred journal and conference papers in the above research fields. He is the receipt of CEC-ICMC Meritorious Student Paper Award (1999), National Excellent Ph. D. Dissertation Award (2002), and Young Investigator Award of Chinese Association of Refrigeration (2007); and was honored Danfoss Honoring Professor (2005).

Prof. Zhang
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