Afternoon Lectures

My group's research focuses on fundamental advances in numerical algorithms and understanding of flow physics that allow the reliable prediction of marine engineering turbulent flows. This presentation will discuss key aspects of such simulation, termed large eddy simulation (LES) alongside illustrative examples. The basic ideas and challenges behind this methodology will be discussed. The predictive capability of LES will be demonstrated for propeller flows and hull flows. The modeling and simulation of cavitating flows will be discussed. Recent developments in the modeling of drag reduction due to superhydrophobic surfaces will be presented. LES results will be shown to be in good agreement with experiments and used to discuss aspects of the underlying physics. The presentation will conclude with future developments in the simulation of fluid-structure interaction, and the simultaneous assimilation of simulation and experimental data.

Krishnan Mahesh
Richard B Couch Professor of Naval Architecture and Marine Engineering
University of Michigan

Krishnan Mahesh is the Richard B. Couch Professor of Naval Architecture and Marine Engineering, with appointments in the Mechanical Engineering and Aerospace Engineering Departments at the University of Michigan. He is Founding Director of the Center For Naval Research and Education at the University of Michigan.

Mahesh's research focuses on algorithm development, theoretical analysis and modeling of multi-physics turbulent flows. He received his Bachelor's degree in Mechanical Engineering from the Indian Institute of Technology, Mumbai, and Masters and PhD degrees in Mechanical Engineering from Stanford University.

Mahesh is a 2018 Fulbright-Nehru Specialist, Fellow of the American Physical Society, Associate Fellow of the American Institute of Aeronautics and Astronautics, and Fellow of the Minnesota Supercomputing Institute. He is a recipient of the CAREER Award from the National Science Foundation and the Francois N. Frenkiel award from the American Physical Society. He has received the Taylor award for Distinguished Research, McKnight Presidential Fellowship, Guillermo E. Borja award and McKnight Land-Grant Professorship from the University of Minnesota. Mahesh's papers have received best paper awards from the Fifth International Symposium on Marine Propulsors in 2017, and AIAA Hampton Roads Section Young Professional Paper Competition in 2021. Mahesh has around 200 publications in journals and refereed conferences, and has graduated 29 PhD students.

 

Ronald W. Yeung, Ph.D.
Distinguished American Bureau of Shipping Endowed Chair, Emeritus
University of California, Berkeley

Abstract: Bearing in mind the world's interest in energy savings and environmental sustainability, the speaker will first review and explore the rational analysis of ship powering from the standpoint of fluid physics. Owing to the phenomenon of Interference Resistance, multi-hull systems can be shown to have lower overall wave drag than a mono-hull of the same displacement. Relevant extensions of this concept to ACVs and SES are discussed. Treatment to optimize hull configuration using machine learning is illustrated. The promise of intelligent ship routing in seaway for time and fuel savings is a challenge. Next, on maritime renewables, the origin of "The Berkeley Wedge" to serve as a perfect breakwater and wave-energy absorber, concurrently, is explained. In contrast, for a three-dimensional point absorber, the adverse effect of viscous damping is clearly revealed by analysis. The introduction of modern control theory to determine the desirable time-varying extraction damping is demonstrated. Outstanding technical issues in digital simulation are pointed out. The talk will conclude with a showing of the evolving success of floating offshore wind turbines as a reliable source of energy supply.

Biography: Professor Ronald Yeung received his Ph.D. (1973), M.S. (Naval Architecture, 1970) and B.S. (Mechanical Engineering, 1968) from the University of California, Berkeley, where he is currently Distinguished Professor Emeritus. He also previously served as an associate and assistant professor in the Ocean Engineering Department at the Massachusetts Institute of Technology (MIT, 1973-82). In between his master's and doctoral studies, he staffed as a naval architect at Litton Ship Systems in Culver City, California and concurrently as a part-time instructor at the Long Beach Naval Shipyard.

Professor Yeung has contributed a broad range of original research to the marine field. Beginning in 1973, his most prominent research spanned from computational methods for ship motion, for ship-ship interaction to his more recent efforts: discrete vortex methods, roll-motion damping modeling, interfacial waves in stratified fluids, and ocean renewable energy via wind and waves. A Special Symposium on offshore and ship hydrodynamics was held in his honor in OMAE-2012, Rio de Janeiro.

Among many honors he received, Professor Yeung was a Fulbright-Hayes Senior Scholar (1980-81) in Adelaide, Australia, a U.S. Distinguished Scientist of the Alexander Von Humboldt Foundation (Hamburg, 1988 & Duisburg, 1998), the 2002-03 Georg Weinblum Lecturer (U.S. Naval Studies Board and the German Schiffbautechnische Gesellschaft), the SNAME Kenneth Davidson Gold Medalist (2004) for outstanding scientific research accomplishments, the Biennial SOBENA international researcher of Brazil (2008), the Inaugural ABS Endowed Chair in Ocean Engineering at UC Berkeley (2012), and The ASME OOAE-Division Lifetime Achievement Award (2016) from the OMAE community, for significant contribution in hydromechanics and ocean engineering as a distinguished scholar. In his 45-year's career, Yeung has supervised 30 doctoral theses and over 100 master's graduates and visiting scholars. He published merely 200 peer-reviewed papers, but his research and mentorship were distinctive and impactful. His advisees have won 16 U.S. and international Best-Paper Awards; many are active in academia and the ocean industry. After retiring from teaching in 2017, he received the prestigious Offshore Technology Conference (OTC) Distinguished Achievement Award (for Individuals) in 2020, citing his original research contribution and educating of two generations of maritime students. Apart from research and education, Yeung has also dedicated his time to serving on editorial boards of professional journals, advisory boards for multiple educational institutions, and the Transportation Research Board of U.S. National Academy of Sciences.

 

Prof. Kristi Morgansen
Boeing-Egtvedt Endowed Chair for Excellence in Engineering
University of Washington

Abstract: Effective decision making requires timely access to reliable and meaningful data. In many current applications, these data are needed in large volume, at high rate, and across large distances. Following the acquisition of data, one is then faced with extracting information that is relevant to the decision-making tasks and can be acquired efficiently. This presentation will address tools and recent outcomes from nonlinear control theory to address these challenges with an eye toward applications in both environmental monitoring and the systems to perform that monitoring, particularly autonomous systems. Many analytical methods for data processing provide a clear framework for careful proof of system capabilities but suffer from mathematical complexity and lack of scaling as probabilistic structure is incorporated. Conversely, machine learning methods provide viable results for probabilistic and stochastic structures, but they are not generally amenable to rigorous proof of performance. The particular tools to be presented here focus on the use of analytical and empirical observability techniques and leverage nonlinear effects such as coupling of sensing and motion. These methods provide mechanisms for characterizing the bounds on data quality and admit the consideration of stochastic model frameworks that have implications for machine learning methods. Application of these tools will be discussed relative to both engineering and biological systems in the form of pose estimation from vision, effective strain sensor placement on insect wings and flexible structures for inertial measurements, and placement of mobile sensor systems for network and environmental monitoring.

Biography: Dr. Kristi A. Morgansen is the Boeing-Egtvedt Endowed Chair for Excellence in Engineering in the University of Washington College of Engineering, and Professor and Department Chair of the UW William E. Boeing Department of Aeronautics & Astronautics. She received a BS (1993) and a MS (1994) in Mechanical Engineering from Boston University, and an S.M. (1996) in Applied Mathematics and a PhD (1999) in Engineering Sciences from Harvard University.

Her research interests focus on nonlinear systems where sensing and actuation are integrated, stability in switched systems with delay, and incorporation of operational constraints such as communication delays in control of multi-vehicle systems. Applications include both traditional autonomous vehicle systems such as fixed-wing aircraft, launch vehicles, and underwater gliders as well as novel systems such as bio-inspired underwater propulsion, bio-inspired agile flight, human decision making, and neural engineering. Her work includes over 100 peer-reviewed publications as well as field testing in commercial systems such as the Boeing ecoDemonstrator.

Dr. Morgansen is a Fellow of AIAA, a member of the Board of Directors of the Washington State Academy of Sciences, and past Chair of the AIAA Aerospace Department Chairs Association. She is co-Founder and co-Director of the UW Space Policy and Research Center (UW SPARC) and Director of the Washington NASA Space Grant Consortium. She has received an NSF CAREER award (2003) and the AACC O. Hugo Schuck award for best paper in the theory category (2009).