JFM Symposia - cambridge.org · 2 JFM Symposia: From Fundamentals to Applied Fluid Mechanics We are delighted to announce the second series of mini-symposia organised jointly by the

JFM Symposia:From Fundamentals to Applied Fluid Mechanics

SPEAKER BIOGRAPHIESAND ABSTRACTS

7-8 NOVEMBERZheijiang University, Hangzhou

Day 1 - JFM SymposiumDay 2 - Publishing Workshop

and Lab Tours

JFM A4 Abstract Booklet Hangzhou v3.indd 1 23/10/2018 14:02

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JFM Symposia: From Fundamentals to Applied Fluid Mechanics

We are delighted to announce the second series of mini-symposia organised jointly by the Editorial Board members of the Journal of Fluid Mechanics and world-class researchers based in China, notably Shenzhen, Hangzhou and Beijing.

The symposia will bring together leading researchers from across the breadth of fluid mechanics from fundamentals to applied interdisciplinary research including aeronautics, astrophysics, biology, chemical and mechanical engineering, hydraulics, materials, meteorology, oceanography, geology, acoustics and combustion.

SYMPOSIA ORGANISING COMMITTEE:Shiyi Chen, Southern University of Science and Technology, ChinaPaul Linden, University of Cambridge, UKShuhong Liu, Tsinghua University, ChinaCharles Meneveau, Johns Hopkins University, USAChao Sun, Tsinghua University, ChinaKathleen Too, Cambridge University Press, UKMinping Wan, Southern University of Science and Technology, ChinaGrae Worster, University of Cambridge, UKKe-Qing Xia, Southern University of Science and Technology, ChinaZhenhua Xia, Zhejiang University, China

LOCAL ORGANISING COMMITTEE:Lily Chua, Cambridge University Press, SingaporeEric Na, Cambridge University Press, Beijing, ChinaLinglei Meng, Cambridge University Press, Beijing, ChinaFanny Wong, Cambridge University Press, Hong Kong, ChinaSybil Zhuo, Cambridge University Press, Beijing, China

ABOUT THE SYMPOSIA CONTENTS

Welcome .......................................................................................... 3

Hangzhou Agenda ............................................................................ 4

Keynote Speakers ............................................................................. 5

Local Speakers .................................................................................. 8

Cambridge University Press Speakers ............................................... 13

Workshop Lectures ......................................................................... 14

Cambridge University Press Staff ..................................................... 15


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Dear Colleagues,

Cambridge University Press is delighted to be co-organising this JFM Symposium: From Fundamentals to Applied Fluid Mechanics, together with the Zhejiang University. We would like to give special thanks to our hosts Professors Jianzhong Lin, Xueming Shao, Zhaosheng Yu, Zhenhua Xia and Jian Deng for their generous help and support of the meeting and for agreeing to co-host this symposium.

The Journal of Fluid Mechanics (JFM) was founded in Cambridge by George Batchelor in 1956 and has become the leading journal in the field. The Journal has grown very significantly in capacity and in breadth, as indeed the subject of fluid mechanics itself has grown from traditional areas of engineering science to engage with almost every area of science and technology.

We are pleased to be joining colleagues from China to share our exciting ideas in research with this audience. And we are delighted to have this opportunity to share our experiences of scientific publication, whether as authors or editors, so that we can understand more clearly how the Journal of Fluid Mechanics can best serve the global scientific community.

We would like to thank all of speakers, organisers, editors and committee members especially our JFM Associate Editor, Professor Ke-Qing Xia. We hope that all presentations will stimulate exchange of ideas, experiences and potentially foster future research collaborations. Welcome to what promises to be an exciting meeting!

GRAE WORSTEREditor-in-ChiefJournal of Fluid MechanicsUniversity of Cambridge, UK

CHARLES MENEVEAUProfessor of Mechanical Engineering, Johns Hopkins University, USA

MANDY HILLManaging DirectorAcademic Publishing Cambridge University Press, UK

KATHLEEN TOOPublisher, Physical Sciences, STM JournalsCambridge University Press, UK

Welcome

Dear Colleagues,

It is a great honour for the Department of Mechanics, Zhejiang University at Hangzhou to host the second JFM symposium in China. On behalf of the local organising team we are delighted to invite you to join this unique event.

Zhejiang University (ZJU) is a member of C9 League in China. As China endeavours to build a community with a shared future for mankind, new opportunities abound in its higher education landscape. In 2017, while celebrating its 120th anniversary, ZJU was proudly selected for China’s “Double First-Class” Initiative. Embarking on a new journey, ZJU is keen to further open up to the world and collaborate globally for the betterment of public welfare. The symposium will be held in Yuquan Campus, which is located within walking distance to the West Lake and Hangzhou Botanic Garden.

Fluid mechanics research at Zhejiang University spans a wide range of topics and departments, including: turbulence; multiphase flows; hydrodynamics and turbomachinery fluid mechanics at the Department of Mechanics; coal combustion at the Department of Energy Engineering; hypersonic and rarified flows at the Department of Aeronautics and Astronautics; complex fluids at the Departments of Chemical and Polymer Engineering; Micro-fluidics at the Department of Mechanical Engineering; and bio-fluid mechanics at the school of Medicine. As a well-established and fundamental discipline, fluid mechanics has been playing an important role on ZJU’s interdisciplinary development strategy, bringing together researchers in many different schools and departments.

At the symposium, there are excellent technical talks and ample time for networking with the JFM editorial team. We look forward to interacting with the fluid mechanics community in and around Hangzhou, and with the highly regarded editors of the Journal of Fluid Mechanics.

The JFM editorial team and the local organising team hope to make this JFM symposium an exciting and memorable scientific event. You will also have the opportunity to visit a hospitable and attractive city with many cultural attractions. We look forward to meeting you in Hangzhou in November 2018.

JIANZHONG LINProfessor, Department of Mechanics, Zhejiang University, China

XUEMING SHAO Professor, Department of Mechanics, Zhejiang University, China

ZHAOSHENG YU Professor, Department of Mechanics, Zhejiang University, China

ZHENHUA XIAPrincipal Investigator, Department of Mechanics, Zhejiang University, China

JIAN DENGAssociate Professor, Department of Mechanics, Zhejiang University, China


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Hangzhou Agenda

Time Lecture Chair

09.00-09.30 Opening speech from Zhejiang University and Cambridge University Press

Colm Caulfield, University of Cambridge09.30-10.00 Dynamics of Coherent Structures in Turbulent

Thermal ConvectionKe-Qing Xia, Southern University of Science and Technology

10.00-10.30 Fate of particles impacting onto a liquid pool: effects of wettability and pool boundariesHang Ding, University of Science & Technology of China

10.30-11.00 Coffee/Tea break

11.00-11.30 Modeling the dynamics of turbine wakes for wind farm controlCharles Meneveau, Johns Hopkins University

Jian Deng, Zhejiang University

11.30-12.00 Propagation and runup of tsunami on a conti-nental shelf of gentle slopeHua Liu, Shanghai Jiao Tong University

12.00-12.10 Introduction to Books @ Cambridge University PressDavid Liu, Cambridge University Press

12.10-13.30 Lunch and Poster Session

13.30-14.00 Droplets and bubbles with phase transitionsDetlef Lohse, University of Twente

Qi Gao, Zhejiang University14.00-14.30 Small-Scale Properties of 2D Rayleigh-Taylor

TurbulenceQuan Zhou, Shanghai University

14.30-15.00 Transition in Hypersonic Boundary LayerCunbiao Lee, Peking University

15.00-15.30 Coffee/Tea break

15.30-16.00 Numerical simulations of the elasto-inertial particle migration in rectangular channel flow of viscoelastic fluidsZhaosheng Yu, Zhejiang University

Zhenhua Xia, Zhejiang University

16.00-16.15 What does a JFM Editor look for when assessing a paper?Charles Meneveau, Johns Hopkins University

Kathleen Too, Cambridge University Press

16.15-17.15 JFM panel discussionsCharles Meneveau, Johns Hopkins University Detlef Lohse, University of Twente Colm Caulfield, University of Cambridge Ke-Qing Xia, Southern University of Science and Technology

17.15-17.30 Closing remarks

Workshop with librarians and students

8 November 2018

Time Lecture

09.00-09.30 Introduction to Cambridge University Press and Cambridge CoreChris Liu, Cambridge University Press

09.30-10.30 Publishing WorkshopKathleen Too, Cambridge University Press

10.30-11:15 Discussions and coffee break

7 November 2018


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Keynote Speakers

KE-QING XIAContact information: Department of Mechanics and Aerospace EngineeringSouthern University of Science and TechnologyShenzhen, ChinaPhone: +86 13691871041Email: [email protected]

ABSTRACTTitle: Dynamics of Coherent Structures in Turbulent Thermal Convection

A hallmark of fluid turbulence is the existence of an extremely large number of degrees of freedom. The formation of large-scale flow structures, or coherent structures, may simplify the description of turbulent flows. Instead of taking into account all the high-dimensional space, one can capture the essential coherent structure dynamics by considering only a few relevant flow modes and model the others stochastically.

In this talk I will present two examples using such dynamical systems or statistical mechanics approach. The first one is turbulent annulus Rayleigh-Bénard convection (RBC), in which a flow topology transition from a high-symmetry high-heat-transport efficiency quadrupole state to a low-symmetry low-heat-transport

efficiency dipole state is observed as the turbulence level increases. This transition is accompanied by a global bifurcation of the mean flow, which is reminiscent of the spontaneous symmetry breaking that usually results in phase transitions in condensed matter physics. The second one is the motion of vortices, or convective Taylor columns (CTCs), in rotating RBC, in which the horizontal motions of the CTCs show Brownian type behaviour, i.e. their short time behaviour is ballistic and crosses over to diffusive in long time. Very interestingly, although the motions of the vortices are random in time, they exhibit ordering in space. The present findings should stimulate more studies of turbulent flows from the dynamical systems point of view, which should also have implications beyond fluid dynamics.

Ke-Qing Xia received his B.S degree in Physics in 1981 from Lanzhou University, China and PhD in Physics in 1987 from University of Pittsburgh, USA. He conducted postdoctoral research in the University of North Carolina and Cornell University prior to joining the Chinese University of Hong Kong (CUHK) in 1992. In the autumn of 2018, he joins the Southern University of Science and Technology (SUSTech) as a Chair Professor and take a professional leave from CUHK where he is Choh-Ming Li Professor of Physics. Ke-Qing Xia’s research is primarily in the experimental studies of fluid turbulence, in particular thermally driven turbulent flows and laboratory study of geophysical flows. These include: enhancement of scalar transport in turbulent flows; oceanic mixing and internal waves; studies of coherent structures in turbulence from the point of view of dynamical systems and statistical mechanics.

Xia is a recipient of China State Natural Science Award, China Higher Education Science and Technology Award and the Croucher Senior Research Fellowship; and is a Fellow of the American Physical Society. Ke-Qing Xia has been an Associate Editor of the Journal of Fluid Mechanics since 2016.


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CHARLES MENEVEAUContact information: Department of Mechanical EngineeringJohns Hopkins University, Whiting School of EngineeringLatrobe 127, 3400 North Charles StreetBaltimore, MD 21218-2682United States of AmericaPhone: (410) 516-7802Fax: (410) 516-7254Email: [email protected]

ABSTRACTTitle: Modelling the dynamics of turbine wakes for wind farm control

Recent advances are rapidly changing the composition of power grid energy sources, replacing conventional power sources with variable resources, such as wind energy. In order to improve the integration of highly variable wind power with the electric grid requires improved methods for controlling wind farms. And, model-based control schemes must be based on reduced-order models of the most relevant fluid dynamics, so that the schemes can be implemented in real time. Turbine – turbine interactions through wakes represent one of the most important fluid dynamical phenomena in wind farms. We here describe a new deterministic dynamic wake model, its use for wind farm control, and its extension to the case of yawed wind turbines.

Yawing wind turbines has emerged as an appealing method for wake deflection. However, the associated flow properties, including the magnitude of the transverse

velocity associated with yawed turbines, are not fully understood. We show that viewing a yawed turbine as a lifting surface with an elliptic distribution of transverse lift enables us to use Prandtl’s lifting line theory to predict the transverse velocity and magnitude of the shed counter-rotating vortex pair known to form downstream of the yawed turbine. The streamwise velocity deficit behind the turbine can then be obtained using classical momentum theory. This new model for the near-disk inviscid region of the flow is compared to numerical simulations and found to yield more accurate predictions of the initial transverse velocity and wake skewness angle than existing models. We use these predictions as initial conditions in a wake model of the downstream evolution of the turbulent wake flow and compare predicted wake deflection with measurements from wind tunnel experiments. The work to be presented arose from collaborations with Carl Shapiro, Dennice Gayme and Johan Meyers, with funding from the National Science Foundation.

Charles Meneveau is the Louis M. Sardella Professor in the Department of Mechanical Engineering at Johns Hopkins University and is Associate Director of the Institute for Data Intensive Engineering and Science (IDIES) at Hopkins. He received his B.S. degree from the Universidad Técnica Federico Santa María in Valparaíso, Chile, in 1985 and M.S, M.Phil. and Ph.D. degrees from Yale University in 1987, 1988 and 1989, respectively. During 1989/90 he was a postdoctoral fellow at the Center for Turbulence Research at Stanford. He has been on the Johns Hopkins faculty since 1990. His area of research is focused on understanding and modeling hydrodynamic turbulence, and complexity in fluid mechanics in general. He has been Editor-in-Chief of the Journal of Turbulence and has served as Deputy Editor of the Journal of Fluid Mechanics since 2010.

Professor Meneveau is a member of the US National Academy of Engineering (2018), a foreign corresponding member of the Chilean Academy of Sciences (2005), and a Fellow of the American Academy of Mechanics, the U.S. American Physical Society and the American Society of Mechanical Engineers. He received an honorary doctorate from the Danish Technical University (in 2016), the inaugural Stanley Corrsin Award from the American Physical Society (2011), the Johns Hopkins University Alumni Association’s Excellence in Teaching Award (2003), and the APS’ François N. Frenkiel Award for Fluid Mechanics (2001).

Keynote Speakers


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Keynote Speakers

DETLEF LOHSEContact information: University of TwenteFaculty of Science and TechnologyHorst – Meander 261P.O. Box 2177500 AE EnschedeThe NetherlandsPhone: +31 53489 8076Email: [email protected]

ABSTRACTTitle: Droplets and bubbles with phase transitions

In this talk I will describe and explain several simple experiments in which phase transitions in and around single droplets and bubbles play an important role. The talk will cover vapour bubbles and freezing and boiling droplets, on cold and hot surfaces, and in cold and hot surrounding liquid, showing beautiful and often unexpected phenomena.

One example consists of a drop of water that freezes from the outside: the expansion of water upon freezing is incompatible with the self-confinement by a rigid ice shell. Using high-speed imaging we show that this conundrum is resolved through an intermittent fracturing of the brittle ice shell and cavitation in the enclosed liquid, culminating in an explosion of the partially frozen droplet. We propose a basic model to elucidate the interplay between a steady buildup of stresses and their fast release. The model reveals that for millimetric droplets the fragment velocities upon explosion are independent of the droplet size and only depend on material properties (such as the tensile stress of the ice and the bulk modulus of water). For small (submillimetric) droplets, on the other hand, surface

tension starts to play a role. In this regime we predict that water droplets with radii below 50 μm are unlikely to explode at all. We expect our findings to be relevant in the modelling of freezing cloud and rain droplets.

Another example is a liquid droplet that impacts a solid surface so hot that enough vapour is generated under it to prevent its contact with the solid. The minimum solid temperature for this so-called Leidenfrost effect to occur is termed the Leidenfrost temperature. We observe the wetting or drying and the levitation dynamics of the droplet using high-speed total internal reflection imaging, which enables us to observe the droplet base up to about 100 nm above the substrate surface. By this method we are able to reveal the processes responsible for the transitional regime between the fully wetting and the fully levitated droplet as the solid temperature increases, thus shedding light on the characteristic time and length scales setting the dynamic Leidenfrost temperature for droplet impact on an isothermal substrate.

Detlef Lohse studied physics at the Universities of Kiel & Bonn (Germany), and got his PhD at Univ. of Marburg (1992). He then joined Univ. of Chicago as postdoc. After his habilitation (Marburg, 1997), in 1998 he became Chair at Univ. of Twente in the Netherlands and built up the Physics of Fluids group. Since 2015 he is also Member of the Max Planck Society and of the Max-Planck Institute in Göttingen and since 2017 Honorary Professor at Tsinghua Univ., Beijing.

Lohse’s present research focuses on turbulence and multiphase flow and micro- and nanofluidics (bubbles, drops, inkjet printing, wetting). He does both fundamental and more applied science and in his group combines experimental, theoretical, and numerical methods.

Lohse is Editor of J. Fluid Mech. and Ann. Rev. Fluid Mech. (among others journals) and serves as Member at Large of the Executive Board of DFD. He is Member of the (American) National Academy of Engineering (2017), of the Dutch Academy of Sciences (KNAW, 2005), the German Academy of Sciences (Leopoldina, 2002) and Fellow of APS (2002). He won various scientific prizes, among which the Spinoza Prize (NWO, 2005), the Simon Stevin Meester Prize (STW, 2009), the Physica Prize of the Dutch Physics Society (2011), the AkzoNobel Science Award (2012), two European Research Council Advanced Grants (2010 & 2017), the George K. Batchelor Prize (IUTAM, 2012), and the APS Fluid Dynamics Prize (2017).


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HANG DINGContact information:Department of Modern Mechanics,University of Science and Technology of China,Hefei 230027, P.R. ChinaEmail: [email protected]

ABSTRACTTitle: Fate of particles impacting onto a liquid pool: effects of wettability and pool boundaries

Interaction of objects with a liquid–gas interface is relevant to a variety of applications in natural and industrial processes, e.g. water entry of solid objects, locomotion of insects on water, self-assembly of particles and fibres at fluid–fluid interface, mineral flotation, wet scrubbing and the design of water walking microrobots. These fluid-structure interactions generally involve dynamic wetting, and some related flow phenomena such as splashing and cavity evolution, have been extensively investigated previously. Here, we mainly focus on the interaction of small objects with the interfaces, in which the process of dynamic wetting is very important and can lead to fascinating flow phenomena. In this talk, we will introduce our recent progress in the experimental and numerical studies of the dynamics of a hydrophobic particle impacting onto a liquid pool, which was previously found to end up with: sinking into the water, bouncing back into the

air, or being entrapped at the interface (and oscillating with capillary waves), even the particle was denser than the water. We investigate the role of wettability of the particle and the effect of the pool boundaries on the fate of the particle, and in particular, to what extent they can determine whether the particle is entrapped at the interface. For this purpose, a diffuse-interface immersed-boundary method recently proposed by us is adopted in the numerical simulations. We expand the parameter space considered previously, provide the phase diagrams and identify the key phenomena in the impact dynamics. To giving a better understanding of the underlying fluid mechanisms, we propose scaling models to interpret the critical conditions for the occurrence of sphere entrapment. They are shown to provide a good correlation among the impact inertia, the surface tension, the wettability and the density ratio of the particle to the liquid.

Dr. Hang Ding is a professor of fluid mechanics in the department of modern mechanics, University of Science and Technology of China (USTC). He received his Bachelor at Nanjing University of Aeronautics and Astronautics in 1993, and obtained his Doctor degree at National University of Singapore in 2005. Later, he worked as a research associate in the chemical engineering at Imperial College London, and then an assistant researcher at University of California, Santa Barbara. He joined USTC in 2011, and was granted by the 100 Talent Program of Chinese Academy of Sciences in the same year. He was supported by the National Science Fund for Distinguished Young Scholars in 2014. His research interests are in the area of multiphase flows simulations, interfacial instability and flows with moving contact lines. In particular, he is interested in the computational modelling of multiphase flows with applications in engineering and science, numerical solutions of such flow problems using the state-of-the-art numerical schemes, and eventually gaining a full understanding of the underlying fluid mechanisms. So far, he has published more than 50 journal articles, including in Annual Review of Fluid Mechanics, Journal of Fluid Mechanics and Journal of Computational Physics.

Local Speakers


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HUA LIU Contact information:School of Naval Architecture, Ocean and Civil EngineeringDepartment of Engineering MechanicsShanghai Jiao Tong UniversityShanghai, P.R. ChinaEmail: [email protected]

ABSTRACTTitle: Propagation and runup of tsunami on a continental shelf of gentle slope

Under the combined action of nonlinearity and dispersion of surface wave, tsunami holds various patterns of wave profiles in offshore region after propagating over a continental shelf of gentle slope. The fully nonlinear and highly dispersive wave model is adopted to simulate the evolution and runup of tsunami from Deep Ocean to

coastal shallow region. Scenarios of extreme tsunami in the South China Sea provide the typical tsunami profile and velocity field along the coastal region. Experimental and numerical results of the runup of the multi-solitary waves and undular bores will be presented and discussed.

Dr. Hua Liu received his first degree and Master degree from Hohai University in 1984 and 1987, respectively, and Ph.D. degree from Shanghai Jiao Tong University (SJTU) in 1991. Since 1991, Dr. Liu has been working at Department of Engineering Mechanics, SJTU, as a lecturer (1991-1993), an associate professor (1993-1998) and a professor (1998-). He is currently a distinguished professor of SJTU and the director of Key Laboratory of Hydrodynamics (Ministry of Education of China) at SJTU. He serves as the Chair of Fluid Mechanics Committee of Chinese Society of Theoretical and Applied Mechanics and a member of the IUTAM Symposium Panel/Fluids. His research interests cover cavitation and cavitating flows, violent flows with the free surface, nonlinear water wave dynamics and tsunami. He has published 100+ papers in the peer reviewed journals and proceedings of international conferences.

Local Speakers


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QUAN ZHOU Contact information:Shanghai Institute of Applied Mathematics and MechanicsShanghai UniversityShanghai 200072P.R. ChinaEmail: [email protected]

ABSTRACTTitle: Small-Scale Properties of 2D Rayleigh-Taylor Turbulence

Rayleigh–Taylor (RT) instability can occur when a layer of heavier fluid is placed on top of a layer of lighter fluid in a gravitational field. The evolution of RT instability would result in the so-called RT turbulence, in which the kinetic energy of the mixed fluid layer increases at the expense of the potential energy and the spectra of velocity fluctuations cover a broad range of scales. The process is relevant in a wide variety of fields in nature and engineering. In addition, this system provides a fascinating fluid mechanical framework for the study of non-stationary turbulent flows. In this talk, we will report a high-resolution numerical study of two- dimensional (2D) miscible RT incompressible turbulence with the Boussinesq approximation. Our main focus is on the temporal evolution and the scaling behavior of global quantities and of small-scale turbulence properties. Our results show that the buoyancy force balances the inertial force at all scales below the integral length scale and thus validate the basic force-balance assumption of the Bolgiano-Obukhov (BO59) scenario in 2D RT turbulence. We also apply a recently developed filtering approach, i.e. filter-space technique (FST), to study the

scale-to-scale transport of kinetic energy, thermal energy, and enstrophy in 2D RT turbulence. Although the scaling laws of the energy cascades in 2D RT systems follow the BO59 scenario due to buoyancy forces, the kinetic energy is still found to be, on average, dynamically transferred to large scales by an inverse cascade, while both the mean thermal energy and the mean enstrophy move towards small scales by forward cascades. In particular, there is a reasonably extended range over which the transfer rate of thermal energy is scale-independent and equals the corresponding thermal dissipation rate at different times. This range functions similarly to the inertial range for the kinetic energy in the homogeneous and isotropic turbulence. Our results further show that at small scales the fluctuations of the three instantaneous local fluxes are highly asymmetrically distributed and there is a strong correlation between any two fluxes. These small-scale features are signatures of the mixing and dissipation of fluids with steep temperature gradients at the fluid interfaces.

Professor Quan Zhou received his bachelor degree from University of Science and Technology of China in 2003. He obtained his PhD degree from the Chinese University of Hong Kong in 2008. Afterwards, he was appointed as an Associate Professor at Shanghai Institute of Applied Mathematics and Mechanics in Shanghai University. He was promoted to a full Professor in 2012. In 2013, he received National Program for Support of Top-notch Young Professionals. He has published more than 30 journal papers including 12 papers in J. Fluid Mech., 5 papers in Phys. Rev. Lett., 5 papers in Phys. Fluids. His research interests include turbulence, heat and mass transfer, and experimental fluid mechanics. He is a member of the Editorial Board for ‘Scientific Reports’, for ‘Journal of Hydrodynamics’, and for ‘Applied Mathematics and Mechanics’.

Local Speakers


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CUNBIAO LEEContact information:Room 7-25College of Engineering, Peking UniversityBeijing 100871, P.R. ChinaPhone: 86-10-6275-5098Email: [email protected]

ABSTRACTTitle: Transition in Hypersonic Boundary Layer

Recently, hypersonic boundary layer transition has become a strategic focus because of its severe impact on the aerodynamic force and heating of a high-speed vehicle. Compared to incompressible flows, hypersonic transition and its effect on aerodynamic heating are less understood owing to additional complexities such as second- and higher-order instability modes and nonlinear coupling of different processes. With the development of test techniques, experimental research of a hypersonic quiet wind tunnel has become essential. A recent experiment was conducted at the Mach 6 quiet wind tunnel at Peking University, investigating flow over an instability-enhanced flared cone model, using three different Reynolds numbers. A host of measurement tools, including pressure sensors, temperature-sensitive paint (TSP), and particle image velocimetry (PIV) provided data for the analysis, using parabolic stability equations (PSE) and direct numerical simulations (DNS).

It is found that second-mode waves, accompanied by high frequency alternating fluid compression and expansion, produce intense aerodynamic heating in a small region that rapidly heats the fluid passing through it. As the second-mode waves decay downstream, the dilatation-induced aerodynamic heating decreases while its shear-induced counterpart keeps growing. The latter brings about a second growth of surface temperature when transition is completed. It is also found that, although the second mode is primarily an acoustic wave, it causes the formation of high-frequency vortical waves. Moreover, the second mode interacts strongly with low-frequency waves, which leads to immediate transition to turbulence. By the way, the interaction and the energy transfer between modes was addressed theoretically and numerically. Analysis of the kinetic energy transfer further shows that the rapid growth of the low-frequency mode is due to the phase locked mechanism interacted with the high frequency mode. The same mechanism also describes the interactions between a second-mode wave and a pair of low-frequency waves. Qualitative agreement with the experimental results is achieved.

Professor Cunbiao Lee received his first degree from the Nanjing University of Aeronautics and Astronautics in 1984. He obtained his master degree in Institute of Mechanics, Chinese Academy of Sciences in 1990 and his Ph.D. from the Beijing University of Aeronautics and Astronautics in 1995. He was employed in the Chinese Institute of Aeronautics in 1984 and started his postdoctor fellowship in the Institute of Atmospheric Physics, Chinese Academy of Sciences in 1995. He joined the Tsinghua University as an associated professor in 1998. He moved to the State Key Laboratory for Turbulence Research and was promoted to full professor at Peking University in 2001. He has published over 70 technical papers and present over 50 invited lectures/seminars. He was awarded the National Outstanding Young Scientist in 2005. He is a deputy director of the State Key Laboratory for Turbulence Research. He was an Editorial Advisory Board member of Experiments in Fluids and is an Editorial Advisory Board member of Phys. of Fluids. His current research interests include boundary layer transition, hypersonic boundary layer instability, falling thin disc in water, PIV measurement and nonlinear wave interaction.

Local Speakers


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ZHAOSHENG YU Contact information:Department of Mechanics, Zheijiang UniversityHangzhou 310027, P.R. ChinaEmail: [email protected]

ABSTRACTTitle: Numerical simulations of the elasto-inertial particle migration in rectangular channel flow of viscoelastic fluids

The migration of particles in a channel flow of Newtonian or non-Newtonian fluids has been attracting much attention due to its scientific significance and important applications such as particle focusing and separation in microfluidics. In this talk, I will introduce our numerical results on the elasto-inertial particle migration in rectangular channel flow of viscoelastic fluids (including Oldroyd-B and Giesekus fluids). Our results indicate that the lateral equilibrium positions located on the cross-section midline, diagonal-line, corner, and channel centerline occur successively, as the fluid elasticity is increased, for the particle migration in the square channel Oldroyd-B flow with finite fluid inertia. The transition of the equilibrium position depends strongly on the elasticity number (the ratio of the Weissenberg number to the Reynolds number) and weakly on the Reynolds number. When the fluid inertia is negligibly small, particles migrate toward the channel centerline, or the closest corner, depending on their initial positions and the Weissenber number, and the corner-attractive area first increases and then decreases, as the Weissenberg number increases. For the particle migration in a

rectangular channel (with the aspect ratio of 2) filled with Oldoyld-B fluids, the transition of the equilibrium position from the midline, ‘diagonal-line’ (actually the line where two lateral shear rates are equal to each other), off-center long-midline, and channel centerline takes place, as the Weissenber number increases at moderate Reynolds numbers. An off-center equilibrium position on the long midline is observed for a large blockage ratio of 0.3 (i.e., the ratio of the particle diameter to the channel height being 0.3) at a low Reynolds number. For the rectangular channel (with the aspect ratio of 2) filled with Giesekus fluids, most particles migrate toward the face centers of the shorter walls, when both fluid inertial and elastic effects are important. In addition, before I introduce the above results, I will briefly introduce the fictitious domain (FD) method used, including the formulation, our numerical schemes, our extensions of the FD method to deal with particle-laden flows with heat transfer, particle dielectrophoresis and fluid/elastic-body interactions, and some numerical examples showing the capabilities of our FD method.

Dr. Zhaosheng Yu received his BS in 1996 and MS in 1999 from the Department of Mechanics, Zhejiang University, Hangzhou, China, and PhD degree in 2004 from the Department of Mechanical Engineering, University of Sydney, Australia (under the supervision of Nhan Phan-Thien and Roger Tanner). He did postdoc at the University of Twente in Netherlands and at IFP in France successively from 2003 to 2006. He was associate Professor in the department of Mechanics of Zhejiang University for 2006-2012, and has been full Professor in Zhejiang University since 2012. He was visiting professors of University of Delaware in 2012 and University of Pennsylvania in 2015. He is currently the director of Fluid Engineering Institute in Zhejiang University. He has been working on the fictitious domain method and its applications in particle-laden flows and flow-structure interactions since 2000. He extended the fictitious domain method to handle the particle-laden flows with heat transfer and the interactions between fluids and flexible bodies. Currently he is using the fictitious domain method to study the mechanisms in the interactions between turbulence and finite-size particles, and the dynamics of particles in viscoelastic fluids. He has published more than 80 journal papers, with more than 1500 citations in Google scholar.

Local Speakers


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Cambridge University Press Speakers

DAVID LIUCommissioning EditorCambridge University PressEmail: [email protected]

ABSTRACTTitle: Introduction to books at Cambridge University Press

We will briefly introduce the academic book publishing at Cambridge University Press, including the history, the publishing process and a glimpse of books in various subjects.

David Liu is currently a Commissioning Editor for engineering books at Cambridge University Press. He commissions textbooks, references, handbooks, monographs, and Elements (short book) series in mainland China, Hong Kong and other Asian Pacific regions. Since he joined the Press in 2013, David has commissioned books in areas such as mechanics, applied fluid mechanics, optics and photonics, communications and signal processing, machine learning and deep learning, and materials science. He holds a MA in Translation and Interpreting from Macquarie University.


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Workshop Lectures

CHRIS LIUSenior Account Executive, China Cambridge University Press Email: [email protected]

Chris Liu is the Senior Account Executive for academic publishing in mainland China, Hong Kong & Macau. He spent 7 years working in the field of international trade before making the move to Cambridge University Press more than 3 years ago. His role currently covers academic sales for customers based in Beijing, Tianjin, Fujian, Sichuan, and Chongqing in mainland China, together with Hong Kong and Macau.

ABSTRACTTitle: Cambridge Core review and how to promote your workChris will be giving a brief introduction of Cambridge University Press. You will hear how the Journal of Fluid Mechanics performs in mainland China, Hong Kong and Macau. We will present a background of Cambridge Core and its innovative functions such as - Cambridge Core Share and give some demonstration on how to get the best from the platform from the perspective of researchers.

KATHLEEN TOOPublisher, STM Journals, UKEmail: [email protected]

Kathleen Too is currently the Publisher for Mathematical and Physical Sciences Journals at Cambridge University Press. She is currently responsible for over 50 journals at CUP covering Mathematics, Computer Science, Earth Sciences, Physics, Engineering and Astronomy. She has 10 years’ experience in managing existing journals and launching new journals. She worked as an Assistant Editor and then a Deputy Editor at the Royal Society of Chemistry. In 2013, she became the International Development Manager for Asia, helping the Royal Society of Chemistry to reach out to emerging markets in Asia. She graduated from the University of Leeds where she did her BSc and PhD and she did a postdoc at the Medical Research Council, Lab of Molecular Biology in Cambridge UK.

ABSTRACTTitle: Publishing WorkshopIn this workshop, aimed at early career researchers, we’ll discuss the nuts and bolts of publishing your research. How should you choose which journal to submit to? How do you approach a publisher if you have an idea for a book? What do editors and referees consider when assessing your work for publication? How does peer review work behind the scenes, and how should you respond to peer reviewers? How do you promote your work post publication? Come along to find out the answers to these questions and many more, followed by an interactive discussion.


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Cambridge University Press Staff

CHRIS LIUSenior Accounts Executive, China

DAVID LIUCommissioning Editor, China

JOHN LINGLEI MENGSenior Commissioning Editor, China

ERIC NAAssociate Account Director, North Asia

KATHLEEN TOOPublisher, STM Journals, UK

ELAINE YEMarketing Executive, China

SYBIL ZHUOMarketing Executive, China


SHENZHENMinping Wan [email protected]

HANGZHOUZhenhua [email protected]

BEIJINGChao [email protected]

Shuhong Liu [email protected]

CONTACT DETAILS

cambridge.org/jfmsymposia

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GENERAL CONTACTS AT CAMBRIDGE UNIVERSITY PRESS (all locations)

Sybil [email protected]

Journal of Fluid Mechanics is the leading international journal in the field and is essential reading for all those concerned with developments in fluid mechanics. Ranked in the top quartile of mechanics journals, JFM covers aeronautics, astrophysics, biology, chemical and mechanical engineering, hydraulics, materials, meteorology, oceanography, geology, acoustics and combustion.

Ranked in top 20 in Mechanics category, and top 10 in Physics, Fluids and Plasmas, in the 2017 Journals Citation Index® (Clarivate Analytics, 2018).

About Journal of Fluid Mechanics

cambridge.org/jfm


Documents

JFM Symposia - cambridge.org · 2 JFM Symposia: From Fundamentals to Applied Fluid Mechanics We are delighted to announce the second series of mini-symposia organised jointly by the