Dr Choongsik Bae

Dean, College of Engineering, Korea Advanced Institute of Science and Technology (KAIST)

Presentation Title: Alternative fuel spray and its application to reciprocating engine

Presentation abstract

This keynote speech will present the spray characteristics of alternative fuels, which are mainly applied to automotive reciprocating engines. Although most of the alternative fuels require high production costs, research on alternative fuels has been actively investigated because of its high potential for improving harmful exhaust emissions and achieving high thermal efficiency. The representative alternative fuels for spark ignition (SI) engines include alcohol fuels, hydrogen (H2), and liquefied petroleum gas (LPG). Biodiesel, di-methyl ether (DME), and jet-propellent-8 (JP-8) can also be classified as alternative fuels for compression ignition (CI) engines. The spray visualization was performed in a constant volume combustion chamber (CVCC) and in the combustion chamber of a reciprocating engine with various visualization techniques. Because the engine combustion can easily be influenced by the characteristics and formation of the spray, research on unidentified spray phenomena is essential. In this keynote speech, the behavior of spray characteristics and its impact on combustion will be delivered regarding various types of alternative fuels. Based on the spray characteristic and its impact on combustion results, the advantages and disadvantages of these alternative fuels are examined and their practicable applications will be discussed.

Speaker Bio

Choongsik Bae received B.S. and M.S. degrees in Aerospace Engineering from Seoul National University, and a Ph.D. in Mechanical Engineering from Imperial College, London in 1993. After two years of research associate experience at Imperial College, he began teaching and research in the Mechanical Engineering Department of the Chungnam National University in 1995. He joined the faculty of the Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST) in 1998. From 2014 to 2017, he served as Chair, School of Mechanical and Aerospace Engineering and Head of Mechanical Engineering. He is also the director of Combustion Engineering Research Center (CERC) at KAIST. He was the Chair of IEA IA ECERC (International Energy Agency Implementing Agreement Energy Conservation and Emission Reductions in Combustion) leading international collaborative tasks in combustion technology among 12 OECD countries through 2011 to 2012. He was the visiting professor of University College of London in 2005. Prof. Bae has been an invited professor at Tokyo Institute of Technology from 2012. He is also actively interacting with industry; having worked as a Technical Advisor of Hyundai Motors during his sabbatical leave in 2011 to 2012. He visited Imperial College of London as an invited professor 2017-2018. From 2018, he has served as the President of ILASS-Korea (Institute for Liquid Atomization and Spray Systems – Korea), and as the Vice-President of KSAE (Korean Society of Automotive Engineers). He was invited as a member of NAEK (The National Academy of Engineering of Korea) in 2019, credited for his achievement on teaching and research. Now, he is the Dean of College of Engineering in KAIST.

Prof. Bae received Arch T. Colwell Merit Award in 1997 and Harry Horning Memorial Award in 2006 from Society of Automotive Engineers (SAE) for his outstanding contribution to the literature in powerplant systems. He was elected as a fellow of SAE in 2012. He received the Academic Award from Korean Society of Automotive Engineers in 2004 and Distinguished Research Award from KAIST in 2011. He was honored as one of the Korea Presidential Researchers in 2000. He received A Man of Merit Award from Ministry of Knowledge Economy (MKE) in 2012. He received the Distinguished Service Award from KAIST in 2018 and an Academic Award from Daejeon Metropolitan City in 2019.

Dr Edouard Berrocal

Associate Professor, Division of Combustion Physics, Department of Applied Physics, University of Lund

Presentation Title: New ways to image sprays

Presentation abstract

Over the past five years a number novel and unconventional spray imaging techniques have been developed, opening new ways for analyzing in detail the process of liquid atomization. Those advances in spray diagnostics include imaging at high-contrast liquid structures present within the spray formation region (using two-photon fluorescence light sheet imaging), sizing droplets in 3D over the entire spray region (using SLIPI-LIF/Mie), temporally resolving at sub-microsecond temporal resolution the early injection of liquid jets from inexpensive LEDs (using FRAME), obtaining the 3D shape of liquid structures based on a single camera recording (using FP-LIF) and, more recently, being able to combine soft X-ray and optical imaging simultaneously by means of a laser-plasma accelerator. This panoply of recent techniques, providing complementary data and having different levels of complexity, will be reviewed in this presentation, together with the corresponding spray situations where they work best.

Speaker Bio

Edouard Berrocal (E.B.) earned a Ph.D. from Cranfield University (UK) in 2007. Since then, he has been working at the Division of Combustion Physics, Lund University (Sweden), where he is currently an Associate Professor. He has also been a Guest Professor at LTT-Erlangen, University of Erlangen-Nuremberg (Germany), since 2014. E.B. is the leader of the “Spray-Imaging group”: https://spray-imaging.com/ which focuses on three aspects related to the characterization of spray systems: 1) Creation and application of novel advanced imaging techniques, 2) Numerical investigation of light propagation and scattering through sprays via Monte Carlo simulation, and 3) Development of optical instruments for droplet sizing and for imaging spray dynamics at high-speed. Over the past decade, E.B. has received several awards, including the Tanasawa Award for the best paper ate ICLASS-2009 and the Young Researcher Award in Advanced Optical Technologies in 2014.

Dr David Schmidt

Professor, Department of Mechanical and Industrial Engineering, University of Massachusetts Amherst

Presentation Title: How the Experimentalists Launched a Paradigm Shift in Spray Modeling

Presentation abstract

Paradigm shifts are triggered by irreconcilable inconsistencies in the prevailing scientific approach, leading to the adoption of new ideas.  When experimental measurements showed that interfacial physics played no role in diesel vaporization, the spray modeling community was presented with a conundrum.  We were eventually forced to admit that droplet-based modeling has served as a poor match for the mixing-limited physics present in many sprays.  The more difficult question, however, is what should replace droplet-based modeling.  I review some promising, yet expensive, Eulerian-based modeling approaches.  In this presentation, I introduce an Eulerian/Lagrangian mixing-oriented approach that is well-suited to the fast interactions found in the dense spray core and which operates at a cost similar to droplet-oriented models.  Designed to avoid empirical parameters, the model can be applied to a wide range of sprays without adjustment.  The success of this model has important implications for where we should go next.  For example, the role of variable-density turbulent mixing now becomes a higher priority for study.  I discuss the impending challenges to our field and provide suggestions for future research directions.  I also point out some important holes in our knowledge, such as the limits of the mixing-limited hypothesis.

Speaker Bio

David Schmidt grew up in North Carolina and attended North Carolina State University as an undergraduate.  He received a Masters of Mechanical Engineering at Stanford University and his PhD. in Mechanical Engineering at the University of Wisconsin, Madison.  In 1997, he helped found Convergent Thinking LLC, a CFD firm that is currently thriving under the name Convergent Science.  Concurrently, David joined MIT as a Visiting Scientist.  Since 2000, he has served on the faculty of the University of Massachusetts. Prof. Schmidt's research is in the fluid mechanics of two-phase flow.  In his thesis work he studied cavitation in diesel fuel injector nozzles.  Since then, he has focused more on flash boiling and external spray evolution.  He is the winner of the Office of Naval Research Young Investigator Award, the Ralph Teetor Award from SAE, the Marshall Award from ILASS, and is an SAE Fellow.