Past Seminars

Adaptive robotic systems using embodied intelligence

Abstract: Current robots are primarily rigid machines that exist in highly constrained or open environments such as factory floors, warehouses, or fields. There is an increasing demand for more adaptable, mobile, and flexible robots that can manipulate or move through complex environments. This problem is currently being addressed in two complementary ways: (i) learning and control algorithms to enable the robot to better sense and adapt to the surrounding environment and (ii) embedded intelligence in mechanical structures. My vision is to create robots that can mechanically conform to the environment or objects that they interact with to alleviate the need for high-speed, high-accuracy, and high-precision controllers. In this talk, I will give an overview of our key challenges and contributions to developing mechanically conformable robots, including soft parallel mechanisms for dexterous manipulation, physically-coupled multi-agent systems, and dynamic origami.

Biographical Sketch: Zeynep Temel is an Assistant Professor with the Robotics Institute at Carnegie Mellon University. Her research focuses on developing robots that can mechanically conform to the environment or objects that they interact with. Prior to joining RI, she was a postdoctoral Fellow at the Microrobotics Lab in Harvard University. She received her Ph.D. from Sabanci University, Turkey, where her work is funded by Turkish Science Foundation. In 2020, she was selected as one of 25 members of the Young Scientists Community of World Economic Forum.

Measurement of non-equilibrium in high-speed hydrogen jet flames using spontaneous Raman scattering

Abstract: Mixing-induced vibrational non-equilibrium was studied in the turbulent shear layer between a high-speed jet and a surrounding hot-air co-flow. The vibrational and rotational temperatures of N2 and O2 were determined by fitting measured spontaneous Raman scattering spectra to a model that allows for different vibrational and rotational temperatures. The mixing of the jet fluid with the co-flow gases occurs over microsecond time scales, which is sufficiently fast to induce vibrational non-equilibrium in the mixture of hot and cold gases. The effect of fluctuating temperatures on the time-averaged Raman measurement was quantified using single-shot Rayleigh thermometry. The Raman scattering results were found to be insensitive to fluctuations except where the flame is present intermittently. Vibrational non-equilibrium was detected in nitrogen but not in oxygen. This difference between species temperatures violates the two-temperature assumption often used in the modeling of high-temperature non-equilibrium flow. A multiple-pass cell was constructed to obtain single-shot Raman scattering measurements in the turbulent shear layer using a pulsed stretched laser. These measurements agreed with the previous time-average results and allowed us to make measurements near the fluctuating base of a lifted flame – a region where time-averaged measurements do not give meaningful results.

Biographical Sketch: Prof. Philip L. Varghese holds the Ernest H. Cockrell Centennial Chair in Engineering at The University of Texas at Austin and has an international reputation in the areas of rarefied and non-equilibrium flows and optical diagnostics for combustion and plasmas. He received his Bachelor of Technology degree from the Indian Institute of Technology in Madras in 1976, an MS from Syracuse University in 1977, and a PhD from Stanford University in 1983 all in Mechanical Engineering. He was a post-doctoral Scholar in the Molecular Physics Laboratory at SRI International and joined UT Austin in 1983 in the department of Mechanical Engineering. He was promoted to Associate Professor in 1988 and transferred to Aerospace Engineering in 1989. He was promoted to full Professor in 1995 and has been the Director of the Center for Aeromechanics Research since 1999. He served as Chair of the Department from 2009-2012.

Among numerous awards he was Fulbright Senior Scholar in France in 1993 and was awarded the Boeing-A.D. Welliver Faculty Fellowship by the Boeing Company in 1998. He received the Lockheed Martin Aeronautics Company Award for Excellence in Engineering Teaching in Spring 2003, and was elected to the Academy of Distinguished Teachers at the University of Texas in 2005. In February 2012 he was selected Professor of the Year by the Senate of College Councils at UT Austin and was awarded The University of Texas System Regents’ Outstanding Teaching Award in August 2016.

Dr. Varghese’s research focuses on understanding the basic molecular processes occurring in high speed, high temperature, and non-equilibrium flows. This is an inter-disciplinary field, requiring a synthesis of physics and chemistry with the more traditional engineering disciplines of fluid mechanics, heat transfer, and thermodynamics. He applies his work to the study of hypersonic and rarefied flows, plasmas, and combustion. He has established a laser diagnostics laboratory for experimental studies in combustion and plasma discharges. He also has an active program in planetary scale simulations of rarefied flows and has developed a novel technique for accurate solutions of the Boltzmann equation using quasi-particle simulation. His research publications have been extensively referenced and a recent search showed over 3800 citations of his work on Google Scholar. He is co-inventor on six US patents related to applications of Raman spectroscopy.

Overview of Advanced Reactor Demonstration Support at Idaho National Laboratory and Modeling & Simulation Capabilities

Abstract: Idaho National Laboratory (INL) is at the forefront of the nation’s advanced reactor R&D effort. Advanced reactor are a promising form of baseload carbon free energy generation and several studies are expecting them to play a critical part in US decarbonization plans. The seminar presentation will be divided in two parts. The first will provide an overview of R&D activities at the lab in support of advanced reactor development efforts. The timeline for forthcoming reactor demonstrations efforts at INL and elsewhere will also be presented. The second part of the seminar will discuss the new ‘multiphysics modeling & simulation’ capabilities being developed at INL as part of the ‘MOOSE’ ecosystem. These tools are being developed primarily to model the complex physics in advanced reactors, but can also be employed to wider engineering applications. They represent a paradigm shit in multi-disciplinary engineering analysis, but enabling the tight coupling of various physical phenomena in nuclear reactors

Biographical Sketch: Dr. Abdalla Abou-Jaoude is an R&D Staff Scientist in the Advanced Reactor Technology Department of Idaho National Laboratory (INL). He is leading efforts in three main areas at INL: advanced modeling & simulation, molten salt irradiation, and nuclear technoeconomics. As the work package manager for the National Reactor Innovation Center’s (NRIC) Virtual Test Bed (VTB), and the Nuclear Energy Advanced Modeling and Simulation (NEAMS) campaign point of contact to the Nuclear Regulatory Commission (NRC), Dr. Abou-Jaoude engages with stakeholders and coordinates different efforts in support of advanced reactor multiphysics simulations capabilities. He is also leading work packages for the NEAMS and Molten Salt Reactor (MSR) campaign on developing multiphysics simulation capabilities for molten salt reactors.

Dr. Abou-Jaoude was awarded an internal lab project to demonstrate molten salt irradiation capability at INL. The project intends to conduct the first fueled chloride salt irradiation in history at the NRAD reactor. Abdalla also serves as Activity Lead for the Systems Analysis & Integration (SA&I) campaign on developing technoeconomic assessment of advanced reactors, notably microreactors. As part of this effort, he developed an “economics-by-design” framework to improve competitiveness of novel concepts and better align them with market needs.

Previously at INL, Abdalla has been involved in various aspect of advanced reactor designs, notably for molten salt reactors, sodium fast reactors (namely the Versatile Test Reactor), nuclear thermal propulsion, and heat-pipe based microreactors. He also previously supported a private-public partnership with a U.S. utility to evaluate hydrogen-cogeneration options at nuclear power plants. He graduated with a doctorate in Nuclear Engineering from Georgia Tech in 2017 and was the INL Deboisblanc Distinguished Postdoctoral Associate during 2018. He obtained a MEng in Mechanical with Nuclear Engineering from Imperial College London in 2013.

Understanding battery safety issues from a mechanics-driven perspective

Abstract: Lithium-ion batteries are one of the critical momentums of our current mobile society. With the further development and application of increasingly high energy density batteries and large capacity battery packs in electric vehicles, cellphones, laptops, and large-scale energy storage systems, the consequences of battery safety issues now become significant threats. Internal short circuits (ISCs) and thermal runaways (TRs) are typical battery safety issues where mechanics, electrochemistry, and thermal are strongly coupled. Interdisciplinary endeavors are in pressing need to address these safety issues. In this talk, multiphysics modeling and characterization at both cell level (~102 mm) and active particle level (~1 μm) will be highlighted to provide a mechanistic understanding of the nature of triggering and evolution of ISCs as well as the responsible mechanical instabilities of the solid-solid interfaces. In the meantime, a machine-learning combined with physics-based modeling will be introduced to achieve faster computation with higher accuracy. Results provide new insights into multiphysics behaviors in battery safety issues and offer engineering-ready modeling methodologies for the next-generation battery design, evaluation, and monitoring.

Biographical Sketch: Dr. Jun Xu joined the Department of Mechanical Engineering at the University of Delaware as an Associate Professor in 2023 Fall. Dr. Xu served as the inaugural Director of NC Battery Complexity, Autonomous Vehicle and Electrification Research Center when he was an Associate Professor at the University of North Carolina at Charlotte. Dr. Xu’s research mainly focuses on multiphysics modeling and characterization of batteries, and impact dynamics. Dr. Xu now serves as an executive committee member of the Advanced Energy System Division, ASME. He is Associate Editor of ASME Journal of Electrochemical Energy Conversion and Storage, Scientific Reports and Batteries. Dr. Xu has published more than 130 peer-reviewed journal papers with citations of 5,400+, H-index 43. Dr. Xu was included in World’s Top 2% Scientist List (Stanford University, 2022) and awarded the prestigious James H. Woodward Faculty Research Award (2021, Chancellor’s Award) and Early-Career Faculty Awards for Excellence in Research (2022) at UNC Charlotte. Dr. Xu earned his Ph.D. degree from Columbia University in 2014.

Weather Forecast and Climate Models in Today’s World

Abstract: Weather Forecast and Climate Models, often referred to as General Circulation Models (GCMs), play pivotal roles in modern society, impacting various sectors, from everyday planning to aviation and national defense. This presentation explores the multifaceted significance of GCMs, both scientifically and economically.

Economically, accurate weather and climate predictions yield an annual economic benefit exceeding $160 billion. Moreover, recent economic assessments conducted across various countries consistently reveal robust cost-benefit ratios for investments in weather and climate services, typically ranging from 1:4 to 1:36. This remarkable potential 2,500% Return On Investment underscores their fundamental societal importance.

This presentation will provide an overview of the historical development of GCMs and shed light on the profound significance of weather and climate predictions in today’s world. It will also delve into the intricacies of GCMs, with an emphasis on their subgrid-scale processes and the methods used to account for them (i.e., parameterizations). Additionally, the application of Computational Fluid Dynamics (CFD) tools, such as large eddy simulations, to help develop and refine parameterizations will be explored.

Biographical Sketch: Dr. Maria Chinita is a researcher at the University of California Los Angeles and Jet Propulsion Laboratory. She earned her PhD in Meteorology from the University of Lisbon, Portugal, in 2018. Her research primarily focuses on atmospheric boundary layers, involving several modeling techniques and observational data to gain a better understanding of small-scale processes. She applies these insights to develop unified parameterizations for atmospheric convection.

Physics-Informed Learning of Melt Pool Dynamics in Metal Additive Manufacturing

Abstract: Metal additive manufacturing (AM), e.g., laser-based powder bed fusion (L-PBF), offers an enabling opportunity for making complex metal parts or customized alloys with design freedom. The unique thermal cycle of rapid heating, fast solidification, and melt-back during metal AM may cause very complex metal pool dynamics, such as steep temperature gradient and high cooling rate, intense Marangoni flow, and intrinsic cyclic heat treatment. The complex very complex kinetic process and thermal history may lead to various quality issues of the printed parts. Therefore, the understanding and prognosis of metal pool dynamics remain the central intractable problem for printing high-quality metal parts or new alloys. Computational fluid dynamics (CFD) models may help to understand the complex thermo-mechanical process physics, but require the calibration of model parameters and are computationally expensive for real-time prognosis. On the other hand, machine learning has the potential to handle high-dimensional and massive process data for efficient surrogate modeling and decision-making. However, pure data-driven machine learning models suffer from black-box or explainability, are inherently computation-intensive and storage-intensive, and need a large amount of high-quality labeled training data to achieve a good performance. A deep knowledge gap exists between machine learning modeling and computational modeling in the prediction of melt pool dynamics. To take full advantage of ML methods while leveraging the physical laws underpinning melt pool dynamics, this talk presents a physics-informed machine learning (PIML) approach to integrate deep learning with the governing equations of the melt pool for forward prediction of the temperature and velocity fields in the melt pool. The PIML approach may also inverse learning of unknown model constants (e.g., Reynolds number and Peclet number) of the governing equations. The robust PIML algorithm also shows fast convergence by enforcing physics via soft penalty constraints.

Biographical Sketch: Dr. Yuebin Guo is Henry Rutgers Professor of Advanced Manufacturing and Leads the New Jersey Advanced Manufacturing Institute at Rutgers University-New Brunswick, USA. Prior to Rutgers, he served as the Assistant Director for Research Partnerships at the U.S. Advanced Manufacturing National Program Office (AMNPO). He was also an Alexander von Humboldt Fellow at RWTH Aachen and Fraunhofer IPT, Aachen, Germany. His research focuses on manufacturing processes, digital twins, physics-informed machine learning, and materials informatics. He is the author of more than 300 peer-refereed technical publications in these areas. He is a recipient of numerous awards, including the SME Sargent Progress Award, ASME Federal Government Swanson Fellow, Tau Beta Pi Outstanding Faculty, NSF CAREER, SAE Teetor Educational Award, and SME Outstanding Young Manufacturing Engineer. He is an elected fellow of ASME, SME, and CIRP.

SpaceChiller: DARPA heat sink technology to enable unprecedented performance of thermoelectric cooling in commercial aerospace systems

Abstract: Thermoelectric coolers (TECs), also known as Peltier coolers, are solid-state cooling devices powered by a direct (dc) current. They offer high reliability, silent operation, and do not require the use of refrigerant chemicals that can be harmful to the environment. However, TEC performance is generally limited as compared to traditional vapor-compression refrigeration systems and this has limited their relevance and applicability, especially when other necessary system components, such as heat exchangers, are considered. RTX Technology Research Center (RTRC) has developed an advanced heat exchanger / heat sink technology on a DARPA program that provides >50% enhancement in heat removal at equivalent operating conditions. Such an improvement means that an air-cooling system can deliver heat-removal performance that approaches that of liquid cooling. When these DARPA heat exchangers are combined with TECs, the resulting cooling system can, for the first time, perform to the level required for galley refrigeration on commercial aircraft. The resulting system, known as SpaceChiller, comes at an opportune time and fills a technology need that is arising in the aerospace industry as airlines start to fly increasingly long distances using small, single-aisle aircraft.

Biographical Sketch: Dr. Pearson has been with RTX Technology Research Center (RTRC, previously known as UTRC) in January 2011. Since then, he has worked on a wide range of projects spanning most of United Technologies’ and RTX’s diverse business units including Pratt & Whitney, Collins Aerospace, Raytheon, and Carrier. Major research areas have included advanced heat exchangers, eco-friendly refrigeration systems, thermally engineered metamaterials, and thermoelectric power generation and cooling. He became a Team Leader of the Heat Transfer team in November 2020. Since October 2022, he has been leading Thermofluid Science Discipline, a team of 15 staff that conduct high-risk and low-TRL research across RTX’s businesses, focused on the company’s unique challenges in heat transfer, fluid dynamics, large-scale thermodynamic systems, and interfacial physics. Dr. Pearson holds a Ph.D., M.S., and B.S. degree in Mechanical & Aerospace Engineering from the Illinois Institute of Technology in Chicago, IL, where he worked on NASA-sponsored work in electrodynamics and was an NSF Graduate Research Fellowship recipient. He has over 23 granted and pending patents and 10 peer-reviewed journal publications.

Lightning Talks: Meet Our Faculty

Three ME faculty will present their research. Come and learn about their exciting research, ask questions, and learn about research opportunities.

Prof. Mihai “Mishu” Duduta obtained his B.S. degree from the Massachusetts Institute of Technology in Materials Science Engineering and received his M.S. and Ph.D. degrees in Engineering Sciences from Harvard University. While at MIT he co-invented semi-solid electrodes for batteries, then after graduating, became the first employee of 24M Technologies, a battery start-up spun out to commercialize the technology. In 2019 he was a Bakken Medical Devices Innovation Fellow at the University of Minnesota – Twin Cities, focusing on finding soft robotic technological solutions to unmet clinical needs, then joined the University of Toronto as an assistant professor in Mechanical and Industrial Engineering until last year. His interdisciplinary research group is focused on soft transducers as building blocks for the next generation of soft machines that can interact safely with humans and disrupt medicine, manufacturing, communications and beyond.

Prof. Wajid Chishty joined the Department of Mechanical Engineering in January 2023. He has a PhD in Mechanical Engineering from Virginia Polytechnic & State University (2005), an MSE in Aerospace Engineering from University of Michigan (1996) and an MBA in Finance from University of Karachi (1991).He has more than 30 years of experience in the areas of gas turbine maintenance, repair and overhaul, combustion research and teaching. He has authored many well-cited publications and is a member of ASME, ASEE and AIAA. His research interests include dynamics of droplets and bubbles, thermoacoustics, aircraft performance and engineering management. He has held senior management positions managing technology transfers and directing applied research in the fields of sustainable aviation, urban air mobility and renewable energy.
Prof. Chang Liu obtained his Ph.D. degree in Mechanical Engineering from Johns Hopkins University in 2021 and then conducted postdoctoral research at the University of California, Berkeley before joining UConn. His research interest is the intersection among fluid dynamics, nonlinear dynamical systems, control theory, state estimation and optimization with a special focus on turbulence. He is interested in developing novel interdisciplinary approaches to obtain reduced-order models and better understandings of fluid dynamics. His current research topics include wall-bounded shear flows, flow control, and thermal convection.

Energy and Emissions in the Built Environment: A Grand Challenge

Abstract: The construction and operation of buildings contribute massively to global energy use and greenhouse gas emissions; therefore, buildings will play a central role in the path toward a sustainable, net zero, clean energy future. This presentation will give a high-level framing of buildings’ role in the 21st century energy challenge, as well as associated opportunities and emerging research, development, demonstration, and deployment (RDD&D) that are developing in response. The talk will start out by quantifying buildings contributions to energy and emissions, and then highlight select ongoing programs and RDD&D efforts at the National Renewable Energy Laboratory (NREL).

Biographical Sketch: Dr. Wale Odukomaiya joined NREL’s Building Technologies and Science Center in 2018 as a Director’s Fellow. His research focuses on innovating heat transfer, energy storage, and functional materials in ways that improve building efficiencies and support low-carbon buildings. This research applies fundamental heat transfer, thermodynamics, and materials science to advanced energy technologies and building components, with an emphasis on thermal and electromechanical energy storage technologies; heating, ventilating, and air conditioning (HVAC); and advanced manufacturing of related components. Prior to joining NREL, Dr. Odukomaiya was a postdoctoral research fellow in the Building Technologies Research and Integration Center at Oak Ridge National Laboratory, where he worked on the development of energy storage and magnetocaloric refrigeration technologies. His research background includes developing advanced energy technologies and building components, energy policy and economics, and thermal and electro-mechanical energy storage.