AUTSE Outstanding Achievement Awardee

Prof. TAO Wenquan Xi'an Jiaotong University, China

Title: Multiscale Numerical Simulation of Boiling Heat Transfer: State of the Art and Challenges

Abstract:

Boiling heat transfer is a typical multiscale problem. Bubble nucleation happens at the microscopic scale, and its growth is usually at the mesoscopic scale; whereas, bubble coalescence, detachment, and development are generally macroscopic behaviors. Usually, different methods, including the MDS, LBM, and FVM are adopted to simulate the boiling heat transfer at different scales. In the 1st part of the lecture, a brief review of the most recent advances in MDS , LBM and FVM for simulating boiling heat transfer will be presented, including the determination of the nucleation time and site by the PK norm, the improved MRT model with a novel force scheme ,and the FVM method VOSET for capturing phase change interface .
In the second part of the lecture the coupling between different scale methods will be discussed. The majority of research on multi-scale coupling simulations has primarily focused on single-phase problems, with limited publications dedicated to boiling heat transfer. Although qualitatively speaking, the three-level numerical methods—MDS, LBM, and FVM—can complement each other to achieve an accurate and reasonable boiling heat transfer simulation, say, predicting from bubble nucleation to the departure from the wall and up-flow of a bubble; However, the coupling between MDS-LBM, MDS-FVM and LBM-FVM meet many difficulties because of the inherent characteristics of the numerical methods at different scales , and these difficulties will be briefly presented.
Finally it is pointed out that the multi-scale numerical investigation of boiling heat transfer is still in its early stages. The realization of coupling MDS, LB, and CFD methods for simulating the full process of boiling heat transfer requires tremendous further researches.

Bio:

Wen-Quan Tao is a Professor in Key Laboratory of Thermo-Fluids Science & Engineering of MOE, and Int. Joint Research Laboratory of Thermal Science & Engineering, Xi’an Jiaotong University, China. He was born in 1939, graduated from Xi’an Jiaotong University in 1962 and received his graduate diploma in 1966 under the supervision of Professor S.M. Yang. From 1980 to 1982 he worked with Professor E.M. Sparrow as a visiting scholar at the Heat Transfer Laboratory of University of Minnesota. He was selected as the National Outstanding Teachers in 2003 and the member of Chinese Academy of Science in 2005. He was the associate editors of the ASME Journal of Heat Transfer, and Int J Heat Mass Transfer. Presently he is the associate editor of the journal of Computers & Fluids. His textbook of 《Numerical Heat Transfer》and 《Heat Transfer》 (co-authored with late Professor SM Yang) has been cited for more than 20000 times both home and abroad. He has supervised more than 160 graduate students. His recent research interests include multiscale simulations of fluid flow and heat transfer problems, enhancement techniques of heat transfer, improvement of hydrogen fuel cell performance, cooling techniques of data center, and energy storage technologies.

AUTSE Young Scientist Awardees

Prof. ZHU Xuancan Shanghai Jiao Tong University, China

Title: Elevated temperature adsorptive separation for hydrogen purification

Abstract:

The reactive separation process based on the coupling of water gas shift (WGS) catalysts and elevated temperature CO₂ adsorbents is able to produce high purity hydrogen directly from H₂-rich gas. This purification technology avoids the sensible heat loss of syngas and the heat regeneration, thus being significantly important to the mitigation of the carbon emission pressure, the development of fuel cell-based energy system, and the reduction of energy consumption in coal chemical industries. In this talk I will report the potassium promoted magnesium-aluminum layered double oxide (K-LDO) based CO/CO₂ purification technology. First, the high-pressure adsorption kinetics of K-LDO is discussed, and a non-equilibrium Elovich-type adsorption/desorption model is built. In situ techniques are adopted to illustrate the elevated temperature CO2 adsorption mechanism of K-LDO. To further increase the CO₂ adsorption performance of K-LDO, the aqueous miscible organic solvent treatment (AMOST) is introduced during the co-precipitation process. In the reactor-scale study, the trace CO/CO2 purification ability of the adsorption column after adding high temperature WGS catalysts is discussed. The effect of operating parameters and the self-purification phenomenon are investigated. A composite column model by coupling the CO2 adsorption and WGS catalysis kinetics, the column mass and momentum balance, and the dynamic boundary conditions is proposed. To achieve continuous hydrogen production, a two-train elevated temperature pressure swing adsorption (ET-PSA) with an 8-column 13-step and a 2-column 7-step processes is built. By adding the high-pressure steam rinse and low-pressure steam purge steps, the system achieves both high H2 purity (>99.999%) and H2 recovery ratio (>95%). When applied in an integrated gasification fuel cell system, the calculated CO/CO₂ purification energy consumption of ET-PSA is 1.11–1.13 MJ/kg, which is 35.1%–36.2% lower than that of the Selexol process.

Bio:

Xuancan Zhu is an associate professor in School of Mechanical Engineering, Shanghai Jiao Tong University. He received his BS and PhD degrees from Tsinghua University in 2014 and 2019, respectively. Dr. Zhu engages in improving the energy efficiency of gas adsorptive separation processes for potential applications in carbon capture and utilization, high-purity hydrogen production, and air separation. Researches include the exploration of adsorption/degradation mechanism, the synthesis of novel physi-/chemisorption materials, the development of low-pressure drop adsorber and efficient adsorption process, the design of capture/purification system for CO, CO2, H2, etc. under mild conditions, and the establishment of technical and economic evaluation criterions of adsorptive separation unit. He was awarded by the Wiley Open Science Excellent Author Program, Author Award of 2021 Chinese Scientists with Cell Press, Excellent Innovation Achievement for Postdoctoral Program, Shanghai Excellent Postdoctoral Fellow, and Tsinghua Excellent Doctoral Dissertation. He is the Young Editorial Member of Clean Coal Technology. As of May 2024, Dr. Zhu has published over 55 journal papers and 1 book that have been cited >1800 times.

Dr. LIU Mengqi Shanghai Jiao Tong University, China

Title: Nonreciprocal thermal radiation using magnetized epsilon-near-zero nanostructures

Abstract:

Thermal emitters/absorbers play an irreplaceable role in several important areas, including but not limited to solar photovoltaics, radiative cooling, thermal camouflage, far/near-field thermophotovoltaics, thermal sources, photothermal conversion and so on.  The majority of thermal emitters/absorbers obey Kirchhoff’s law of thermal radiation, whereby spectral directional absorptivity and emissivity are identical according to Lorentz reciprocity. This restriction introduces an intrinsic loss in a plethora of energy technologies and prevents us from controlling emission and absorption independently. This talk will first give a basic introduction of nonreciprocal thermal photonics, followed by the generalization of Kirchhoff’s law of thermal radiation. Then, the underlying physics and manipulation methods using magnetized epsilon-near-zero nanostructures to diversely control angular/spectral nonreciprocal thermal emission/absorption will be introduced. In addition, several nonreciprocal thermal emitters/absorbers with single, dual, and broadband performance have been experimentally demonstrated. In the end, a brief outlook on the development of nonreciprocal thermal photonics will be discussed.

Bio:

Mengqi Liu is a postdoc at the Institute of Engineering Thermophysics, Shanghai Jiao Tong University, Shanghai, China. She received her BE degree from Shandong University, and PhD degree from Shanghai Jiao Tong University. Dr. Liu was also a joint PhD student at National University of Singapore. Her research interest focuses on micro/nano thermal radiation, nonreciprocal thermal radiation, and metamaterials energy devices. She has published 16 peer-reviewed journal papers, including Nature Materials, Nature Photonics, Physical Review Letters, International Journal of Heat and Mass Transfer, etc.  She received the AUTSE Young Scientist Award in 2024, the Zhonghua Wu Excellent Postgraduate Award in 2022, the Excellent Doctoral Dissertation from Shanghai Jiao Tong University in 2022, etc.

Prof. ISOBE Kazuma Okayama University, Japan

Title: Spectral control of far- and near-field radiation transfer: On receiving the AUTSE Young Scientist Award

Abstract:

A body emits thermal radiation at various wavelengths depending on its temperature and emissivity. Spectral control of thermal radiation is essential in improving thermophotovoltaic power generation and radiative cooling performances. In this decade, researchers have tried to modulate the spectral emissivity of a body artificially using a micro or nanometer-sized structure called “meta-surface.” Especially, a metal–insulator–metal multilayer, periodical grating, pillar, and cavity arrays are promising geometries. These meta-surfaces also affect near-field radiation spectra at a hundred nanometers thickness of vacuum gap between two bodies. It is because meta-surfaces excite limited wavenumbers of surface plasmon polaritons at their surface. This talk will describe how these meta-surfaces affect radiative heat flux spectra and their application benefit

Bio:

Kazuma Isobe is an assistant professor in the Graduate School of Environmental, Life, Natural Science and Technology at Okayama University. He graduated from Tokyo Institute of Technology in March 2020, with a PhD in engineering under the supervision of Professor K. Hanamura. His research interest is mainly in thermal radiation heat transfer. Throughout research career, he has made efforts to control far- and near-field radiation using nano- and micro-structures.

Nukiyama Memorial Awardee

Prof. WANG Zuankai The Hong Kong Polytechnic University, China

Title:  Tackling the centuries-old Leidenfrost effect

Abstract:

From water droplets rolling around on a hot pan without quickly evaporating to splitting molten iron with bare hands, behind these unrelated phenomena lies the Leidenfrost effect discovered in 1756: liquids evaporate from high-temperature surfaces to form a continuous air film blocks the contact between solid and liquid. Although this effect shows broad application prospects in fields such as drag reduction and liquid mixing, it is also a century-old problem that has plagued the field of high-temperature heat dissipation, and even indirectly led to the Fukushima nuclear power plant accident in Japan. How to break this century-old physical effect is a major challenge for many applications.
This seminar will focus on how to use bionic concepts, especially by the heterogeneous integration of materials, thermal-fluids, manufacturing, energy, and other fields, to develop textured materials that fundamentally suppress the century-old Leidenfrost effect for efficient liquid cooling. I will also demonstrate how the heterogeneous design concept can be extended for efficiency enhancements in water harvesting, condensation, energy harvesting, boiling, and other applications.

Bio:

Zuankai Wang is the Associate Vice President (Research and Innovation), Kuok Group Professor in Nature-Inspired Engineering, Chair Professor in the Department of Mechanical Engineering, and Director of Research Center for Nature-Inspired Science and Engineering at The Hong Kong Polytechnic University (PolyU). He received his BSc from Jilin University, his MSc from the Shanghai Institute of Microsystem and Information Technology, and his PhD from the Rensselaer Polytechnic Institute. Before joining PolyU, Prof. Wang was a Chair Professor at the Department of Mechanical Engineering and was the Associate Dean in the College of Engineering at the City University of Hong Kong. He is the Executive Editor-in-Chief of Droplet (Wiley).
Prof. Wang is a Fellow of the Hong Kong Academy of Engineering Sciences, the Royal Society of Chemistry, and the International Society of Bionic Engineering. He has won numerous awards, including the Falling Walls Science Breakthroughs of Year 2023 (Engineering and Technology), Croucher Senior Research Fellowship, Research Grant Council Senior Research Fellowship, BOCHK Science and Technology Innovation Prize, Green Tech Award, Xplorer Prize, and the 35th World Cultural Council Special Recognition Award. He was named as “Highly Cited Researcher” by Clarivate Analytics (2022, 2023).