Mark Miller

Assistant Professor, Department of Aerospace Engineering
Pennsylvania State University

Reynolds number dependence of coaxial rotor wakes in climb and hover

August 28, 2025

Coaxial rotor configurations are becoming more commonplace on specific aerospace applications, such as electric vertical take-off and landing rotorcraft. However, from a fundamental perspective, coaxial rotors have not been studied as extensively as single main rotors meaning that less is known about their underlying fluid dynamics. In this work, the Reynolds number (or scale) dependence of the coaxial rotor wake in axial flight is examined using a specialized, high pressure wind tunnel known as the Penn State Compressed Air Wind Tunnel (CAWT). In this facility, flight-relevant Reynolds numbers can be achieved using relatively small models. Wake surveys were conducted on a coaxial rotor system based on the NASA Dragonfly geometry at several downstream locations to determine the Reynolds number sensitivity for both mean and fluctuating axial velocities. Results indicate that only moderate Reynolds numbers are required before invariance in Re is achieved. Spectra calculated from the axial fluctuating velocity show evidence of wake meandering for rotors in hover. These findings offer the first detailed look into coaxial rotor configuration wake scaling by quantifying how downstream wake dynamics are affected by the flight condition.

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Dr. Mark A. Miller's research at Penn State focusses on the fundamental fluid dynamics of unsteady and rotating systems by using a multifaceted experimental and theoretical approach. Ongoing projects span a wide range of fluid systems including multi-rotor electric Vertical Take-Off and Landing (eVTOL) performance and acoustic characterization, wind turbine aerodynamics, turbulent flows and roughness, as well as the development of innovative sensor systems which are tailored to these specific flow regimes. He is an active member of the American Physical Society, the American Society of Engineering Education, the AIAA, where he serves on the Fluid Dynamics Technical Committee, and the Vertical Flight Society, where he serves on the Test and Evaluation Committee.

Anne Robertson

Distinguished Service Professor, Department of Mechanical Engineering and Materials Science
University of Pittsburgh

Exploring the relationship between arterial wall structure and mechanical function in health and disease using advanced imaging techniques

September 4, 2025

Biological soft tissues such as artery, bladder and cornea are composite materials formed of cellular constituents along with acellular structural materials including collagen and elastin fibers. The organization and distribution of these constituents within each organ are critical for enabling its particular function, such as the remarkable capacity of the bladder to increase its volume over three-fold under small increases in pressure during filling. Forty years ago, Lanir published a seminal paper that recognized the i mportance of including this microstructure in material models for soft tissues. In particular, he introduced a structurally motivated constitutive model for collagenous soft tissues that included the distributions in both collagen fiber tortuosity and angle. However, there were no tools at that time for measuring these distributions and up until recently, most studies have continued to employ phenomenological models. This lecture is focused on recent work that leverages advances in bioimaging technology to obtain the data necessary to develop microstructural models of soft tissues. In particular, the advent of multiphoton microscopy has enabled direct imaging of elastin and collagen fibers in soft tissues without fixation or destructive tissue sectioning. Our group has leveraged these technologies to develop mechanical testing systems to simultaneously image collagen and elastin fiber organization during mechanical experiments. We have used these systems to directly measure the parameters in Lanir's structural models while also exploring how the composite organization in soft tissue drives their mechanical function. Inclusions such as arterial calcification and lipid pools, alter this mechanical function. Applications of these approaches to understanding rupture of cerebral aneurysms, the high compliance of the bladder wall, as well as growth and remodeling in blood vessels will be discussed. The last portion of the talk will cover some of our recent work on the role of the vasa vasorum in brain aneurysms, with a consideration of oxygen transport into the aneurysm wall.

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Dr. Anne M. Robertson is a Distinguished Service Professor and William Kepler Whiteford Endowed Professor of Mechanical Engineering and Materials Science at the University of Pittsburgh. The focus of Dr. Robertson's research is understanding the relationship between structure and mechanical function in biological soft tissues and using this knowledge to improve treatments of disease with a focus on brain aneurysms and bladder. She co-directs a multi-national program on cerebral aneurysms that is supported by the NIH and engages four clinical centers and three universities. She held a four-year term as a standing member of an NIH Study Section in the National Institute of Neurological Disorders and Stroke. She has held visiting faculty positions at institutions including the Bernoulli Center at the Swiss Federal Institute of Technology (EPFL), the Politecnico di Milano, University of Aachen, and Instituto Superior Tecnico, Lisbon. Dr. Robertson earned a B.S. at Cornell University and M.S. and Ph.D. degrees at U.C. Berkeley, all in Mechanical Engineering. She was a President's Postdoctoral Fellow in the Department of Chemical Engineering, also at U.C. Berkeley. Dr. Robertson's leadership roles at Pitt have been largely directed at the success of junior colleagues, including her position as Associate Dean of Faculty Development and founding Director of the Center for Faculty Excellence (CFE) in the Swanson School of Engineering at Pitt. The CFE takes the lead in developing and implementing programs to enhance the effectiveness of junior faculty in building outstanding academic careers.

Stewart Mallory

Assistant Professor, Departments of Chemistry and Chemical Engineering
Pennsylvania State University

From microscopic dynamics to material design in colloidal active matter

September 11, 2025

Colloidal active matter is a new class of synthetic material composed of microparticles that continuously convert chemical energy into directed motion. These nonequilibrium systems can behave like microscopic engines, propelling themselves through fluid in ways reminiscent of bacteria and other swimming microorganisms. Unlike passive colloids, active particles generate persistent motion and interactions that give rise to new forms of transport, collective behavior, and self-assembly at the microscale.

In this talk, I will highlight two directions from our recent work. First, I will discuss how active colloids respond to chemical gradients, drawing parallels with chemotaxis and illustrating how these gradients can be utilized to steer their trajectories. Second, I will demonstrate how sedimentation serves as a simple yet powerful probe of the equation of state in active suspensions, enabling the deduction of their phase behavior and collective dynamics. These insights point toward harnessing active colloids for controlled self-assembly and for designing new strategies to manipulate transport in microfluidic and biologically relevant environments.

Together, these studies demonstrate how colloidal active matter represents both a model system for nonequilibrium statistical mechanics and a prototype for a new class of materials with tunable, dynamic properties.

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Dr. Stewart Mallory is an Assistant Professor in the Departments of Chemistry and Chemical Engineering at The Pennsylvania State University. His research group develops nonequilibrium theories for soft and complex materials, with a focus on colloidal active matter and approaches to control matter and program its self-assembly at the microscale. A central goal of this work is to establish new principles for manipulating transport and designing functional materials far from equilibrium.

Prior to joining Penn State, he was an Arnold O. Beckman Postdoctoral Fellow and AGEP California Alliance Postdoctoral Scholar in the Division of Chemistry and Chemical Engineering at Caltech, working with Prof. John Brady. He earned his Ph.D. in Chemical Physics at Columbia University as an NSF Graduate Research Fellow under the mentorship of Prof. Angelo Cacciuto. He holds B.S. and B.A. degrees in Chemistry and Mathematics, magna cum laude, from the University of Hawai'i.

Cecilia Huertas-Cerdeira

Assistant Professor, Departments of Mechanical Engineering
University of Maryland, College Park

A cyber-physical platform for aeroelastic system characterization and its application to rigid inverted flags

September 18, 2025

The study, optimization and data-driven modeling of aeroelastic systems require evaluating their dynamics for large parametric spaces. Obtaining comprehensive datasets of such systems is challenging as a result of the nonlinear and tightly coupled fluid and structural mechanics that govern their behavior. In this research, a cyber-physical platform is developed that enables fast evaluation of the two-way coupled fluid–structure interactions of a plate with a torsional degree of freedom without modification of experimental hardware. The platform is used to evaluate the dynamics of a rigid inverted flag – a promising configuration for aeroelastic wind energy harvesters. The results are validated with experiments performed on a fully-physical system, and the cyber-physical platform is shown to be capable of replicating both static and dynamic aeroelastic instabilities, limit cycle oscillations, and chaotic dynamics. The platform is then leveraged to study the dynamics of the flag for nonlinear structural behaviors and varying structural damping. The results show that nonlinear structures can be utilized to improve the operational range and harvesting performance of the flag.

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Dr. Cecilia Huertas-Cerdeira is an Assistant Professor in the Department of Mechanical Engineering at the University of Maryland, College Park. She has broad research interests in the fields of Unsteady Fluid Mechanics and Fluid–Structure Interactions. Her group leverages a combination of experimental, analytical and data-driven tools to tackle problems ranging from bio-inspired robotics to efficient aviation, wind energy harvesting and heat transfer enhancement. Dr. Huertas-Cerdeira holds a B.S. and M.S. in Aeronautics from Universidad Politécnica de Madrid (Spain) and ENSMA (France), respectively. She received her Ph.D. in Aeronautics from the California Institute of Technology in 2019, for which she obtained Caltech's William F. Ballhaus Prize. She was the recipient of an NSF CAREER award in 2025.

Banafsheh Seyed-Aghazadeh

Associate Professor, Departments of Mechanical Engineering
University of Massachusetts Dartmouth

Symmetry breaking in fluid–structure interactions

September 25, 2025

When a flexible structure is exposed to fluid flow, it can undergo deformation or oscillation in response to the forces exerted by the flow. In turn, these structural motions alter the surrounding flow field and the forces acting on the structure, creating a continuous interaction between fluid and structure. Such dynamic interactions form the basis of Fluid–Structure Interactions (FSI), and the structural oscillation that is driven by the flow itself is specifically termed Flow-Induced Vibration (FIV).

FIV holds considerable importance across diverse domains, ranging from aeolian harps to critical infrastructures such as offshore platforms, wind turbines, mooring lines, power transmission lines, and undersea pipelines. FIV also plays a critical role in emerging technologies, where it can either pose design challenges or be harnessed for functionality—for instance, it influences energy extraction in fluidic energy harvesters, affects aerodynamic stability in aircraft wings, and contributes to propulsion and sensing capabilities in underwater soft robots.

While most research has traditionally focused on symmetric FSI systems—where the structure, geometry, boundary conditions, and incoming flow are all symmetric—real-world applications often involve asymmetric configurations. In this presentation, I will talk about the fundamental aspects of flow-induced vibration in structures characterized by broken symmetry. Drawing from our laboratory experiments, I will present how different forms of asymmetry influence the system's dynamic response. Furthermore, I will discuss the broader implications of these findings, particularly in advancing energy harvesting techniques and designing fluidic sensors, with promising applications in ocean sensing and exploration.

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Dr. Banafsheh Seyed-Aghazadeh is is an associate professor in the Mechanical Engineering department and serves as the director of the "Laboratory for Fluid–Structure Interactions Studies" at the University of Massachusetts Dartmouth (UMassD). Her contributions to the field have been recognized with prestigious awards, including the National Science Foundation (NSF) CAREER award and the Office of Naval Research (ONR) Young Investigator Program (YIP) award in 2022, along with additional funding support from the ONR, the Department of Energy (DOE), and internal programs such as the Marine and Undersea Technology Initiative and the Blue Economy Initiatives. Dr. Seyed-Aghazadeh's dedication to fostering equity, diversity, and inclusion in academia was honored with the 2023 Faculty Award for Excellence in Equity, Diversity, and Inclusion at the UMassD. Prior to joining UMassD, Dr. Seyed-Aghazadeh held the James R. Myers Endowed assistant professor position at Miami University. Earlier in her career, she served as a postdoctoral research associate and lecturer in the Department of Mechanical and Industrial Engineering at the University of Massachusetts Amherst. She earned her Ph.D. in Mechanical Engineering from the University of Massachusetts Amherst, where her contributions were recognized with the College of Engineering Outstanding Young Alumni Award in 2021. Dr. Seyed-Aghazadeh's research expertise lies in experimental Fluid–Structure Interactions, a field that integrates fluid mechanics research with advanced nonlinear dynamics concepts, offering far-reaching implications across various engineering disciplines.

Emilian Parau

Professor, Departments of Mathematics
University of East Anglia

Hydroelastic waves and other wave–ice interactions

October 2, 2025

In polar regions, floating ice on frozen lakes is often used as a road to access isolated communities. Under certain conditions, the ice can be modeled as a thin plate, and studying hydroelastic waves propagating at the ice–water interface is essential for the safe use of these ice roads. A better understanding of wave–ice interactions in the Marginal Ice Zone (MIZ) is also important in the context of climate change. The MIZ is the area between the open ocean and the continuous ice cover in the Arctic and Antarctic regions. In this talk, I will provide an overview of recent results in these areas of research, with a focus on the effects of nonlinearity.

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Dr. Emilian Parau is a Professor of Applied Mathematics at University of East Anglia, Norwich, United Kingdom. His research focuses on nonlinear water waves, interfacial waves, hydroelastic waves and other free surface flows. He is interested in solving nonlinear partial differential equation arising in fluid mechanics and free boundary problems using computational, asymptotic and dynamical systems methods. He obtained his B.Sc. in Mathematics from the West University of Timisoara, Romania and his Ph.D. in Mathematics in 2000 from University of Nice Sophia Antipolis and West University of Timisoara.

Ugo Piomelli

Professor, Departments of Mechanical and Materials Engineering
Queen's University

Numerical simulations of turbulent flows over rough walls

October 7, 2025

Roughness is present in many applications in engineering, meteorology and the geophysical sciences, and its effects on the fluid flow have been studied for almost a century. Early studies measured only the drag (resulting, for instance, in the well-known Moody diagram); more recently, turbulence statistics have been collected in many geometries. It is very difficult and expensive, however, to measure the flow between the roughness elements; thus, most studies concentrate on the region above the roughness crest, where similarity exists: the roughness determines the velocity scale that makes turbulent statistics collapse. Over the last decade, the development of efficient Immersed Boundary Methods has allowed the numerical simulation of flows over very complex geometries to become feasible. The increase in available computational power, furthermore, has made it possible to reach Reynolds numbers sufficiently high that the effects of roughness are significant while the roughness elements are small enough that the global characteristics of the flow are not affected. Numerical simulations have made the flow between the roughness elements accessible, allowing more complete studies of the momentum and energy transfer mechanisms due to roughness. Examples will be presented to highlight the effects of the interaction between roughness and non-equilibrium turbulence. The effect of roughness on the transport of passive scalars will also be discussed.

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Dr. Ugo Piomelli obtained a Laurea in Ingegneria Aeronautica from the Università di Napoli "Federico II" in 1979. He then earned a Master of Science Degree in Aerospace Engineering from the University of Notre Dame in 1984 and a Ph.D. in Mechanical Engineering from Stanford University in 1988. From 1987 to 2008 he was on the faculty of the Department of Mechanical Engineering at the University of Maryland, first as Assistant, then Associate and finally Full Professor. In August 2008 he joined the Department of Mechanical and Materials Engineering at Queen's University in Kingston, Ontario, where he held, from 2008 to 2022, the Tier 1 Canada Research Chair in Turbulence Simulation and Modelling.

Professor Piomelli has published over 100 refereed journal articles in the fields of turbulence and transition modelling and simulation. His work has been cited over 26,000 times, and he has an h-index of 57 (Google Scholar). He was elected Fellow of the Royal Society of Canada in 2015, of the Canadian Academy of Engineering in 2021, of the American Society of Mechanical Engineers in 2009, and of the American Physical Society in 2002. Since 2015, he has been the Editor-in-Chief of the Journal of Turbulence. His present research includes studies of the flow in rivers and lakes, turbulent boundary layers over smooth and rough surfaces, model development for large-eddy simulations, and flows in hydro-electric turbines and aeronautical applications.

Elias Balaras

Professor, Mechanical and Aerospace Engineering
George Washington University

DNS of turbulent boundary layers over biofouling-type roughness

October 9, 2025

A common and complex roughness type of high importance to the naval engineering and fluid dynamics community is biofouling. Biofouling is the undesirable accumulation of ocean and marine organisms on the hull of naval vessels that leads to excessive fuel consumption. Roughness correlations encapsulating numerous datasets obtained over the years, which are typically utilized to predict the drag penalty over a rough wall, are not directly applicable to calcareous biofouling given that such roughness has high skewness and low effective slope. This work is dedicated to the analysis of turbulent boundary layers developing over biofouling-type surfaces by means of direct numerical simulation (DNS). We will focus on two main aspects: i) the identification of the main topographical parameters that result in the drag-producing physics and ii) the anatomy of the rough-wall fluid-flow in both its statistically-stationarity, as well as its dynamical state. For the latter we employ conditional averages, two-point correlations and modal analysis. Finally, preliminary results over flexible biofouling (slimes) will also be presented.

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Dr. Elias Balaras is a Professor at the Department of Mechanical and Aerospace Engineering at the George Washington University. He also serves as the director for graduate studies at MAE. Dr Balaras's current research program aims at the development of robust numerical techniques for parallel, large-scale simulations of multiscale, multiphysics problems in physical and biological systems. Current research projects cover a wide area of applications from i) medicine, where magnetic resonance imaging data guide high-fidelity computations of the blood flow in the heart of patients with congenital heart disease to optimize surgical treatment; ii) biology, where free-flying insects are simulated to inform the development of engineered micro-flyers; iii) applied industrial processes, where multiscale high-fidelity simulations of liquid metal casting are used to inform low fidelity modeling tools utilized routinely by the industry; iv) to space applications, where boiling in micro-gravity environments is simulated to optimize cooling of various space components. Dr Balaras is also teaching a series of graduate classes related to the science of simulation and advises a group of graduate students in his lab as they tackle these challenging multidisciplinary problems. His main goal as an advisor/educator is to enable graduate students to grow into well rounded computational scientists ready to transition into leadership roles in the field.

Gokul Pathikonda

Assistant Professor, School for Engineering of Matter, Transport and Energy
Arizona State University

Structures in a turbulent boundary layer – their coherent transport behavior and unsteady response

October 9, 2025

With the advances in scale-resolving measurement techniques for complex flow environments, we have gained a mature understanding of dominant coherent structures that populate canonical turbulent boundary layers. For this seminar, we discuss two examples of the complex interplay of turbulent scales that significantly affects the world we live in. First, we look at the dispersion of a passive scalar plume that is injected into a high Reynolds number (Re) turbulent boundary layer using simultaneous planar laser-induced fluorescence (PLIF) and particle image velocimetry (PIV). We focus on the role of the large coherent structures that populate such boundary layers on the break-up, meandering, and dispersion of the scalar plume at early stage. These structures significantly alter the long-range concentration intermittency and instantaneous concentrations further downstream – understanding which is critical for modeling pollutant, aerosol, and particulate transport in atmospheric boundary layers over complex terrains. In a second contrasting example, we present preliminary efforts where we can externally perturb these flows and coherent mechanisms to mimic real-world unsteadiness (such as gusts, vortex-wing interactions, etc.). We do this to study the ensuing changes to the boundary layer behavior such as separation, scalar transport, etc. To this end, we present a 'Translating Rotating Cylinder', 'Dynamic Aspiration System', and a class of herringbone-type 2D and 3D roughness patterns to discuss their effects.

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Dr. Gokul Pathikonda is an Assistant Professor in the School for Engineering of Matter, Transport and Energy (SEMTE) at Arizona State University. His team designs laboratory experiments to identify and measure fundamental turbulence behavior relevant to aerospace, energy, astrophysics, maritime and atmospheric sciences. Specifically, they design innovative boundary layer control approaches and hybrid application of laser-based techniques (particle image velocimetry, laser-induced fluorescence, etc.) to study wall-bounded turbulent flows, shear-driven turbulent mixing, and reacting flows. He is a recipient of 2025 ONR Young Investigator Award, Stanley Weiss Outstanding Dissertation Award and RISE Fellowship. He received his Ph.D. in 2017 in Theoretical and Applied Mechanics from University of Illinois, Urbana-Champaign, and was a researcher at Georgia Tech, Indian Institute of Science and Jawaharlal Nehru Center for Advanced Scientific Research at Bangalore.

Ricardo Vinuesa

Associate Professor, Department of Aerospace Engineering
University of Michigan

Improving turbulence control through explainable deep learning

October 23, 2025

In this work we first use explainable deep learning based on Shapley explanations to identify the most important regions for predicting the future states of a turbulent channel flow. The explainability framework (based on gradient SHAP) is applied to each grid point in the domain, and through percolation analysis we identify coherent flow regions of high importance. These regions have around 70% overlap with the intense Reynolds-stress (Q) events in two-dimensional vertical planes. Interestingly, these importance-based structures have high overlap with classical turbulence structures (Q events, streaks and vortex clusters) in different wall-normal locations, suggesting that this new framework provides a more comprehensive way to study turbulence. We also discuss the application of deep reinforcement learning (DRL) to discover active-flow-control strategies for turbulent flows, including turbulent channels, three-dimensional cylinders and turbulent separation bubbles. In all the cases, the discovered DRL-based strategies significantly outperform classical flow-control approaches. We conclude that DRL has tremendous potential for drag reduction in a wide range of complex turbulent-flow configurations.

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Dr. Ricardo Vinuesa is an Associate Professor of Aerospace Engineering at the University of Michigan. He studied Mechanical Engineering at the Polytechnic University of Valencia (Spain), and he received his Ph.D. in Mechanical and Aerospace Engineering from the Illinois Institute of Technology in Chicago. His research combines numerical simulations and data-driven methods to understand, control and predict complex wall-bounded turbulent flows, such as the boundary layers developing around wings and urban environments. Dr. Vinuesa has received, among others, an ERC Consolidator Grant, the Harleman Lecture Award, the TSFP Kasagi Award, the MST Emerging Leaders Award, the Goran Gustafsson Award for Young Researchers, the IIT Outstanding Young Alumnus Award and the SARES Young Researcher Award. He received the Outstanding Reviewer Prize of the Journal of Fluid Mechanics and he is also a member of the Young Academy of Science of Spain.

Peter Olmsted

Professor, Department of Physics
Georgetown University

Instabilities and shear banding in polymeric fluids

October 30, 2025

Entangled polymer liquids have enormous non-Newtonian effects due to the elasticity of the long molecules. This gives rise to spectacular phenomena such as rod-climbing, shear thinning, and numerous elastic instabilities. One contentious prediction is 'shear banding,' in which a sheared solution divides into 'bands' of different shear rates, with well-aligned and poorly-aligned polymers respectively in the low and high shear rate bands. There have been predictions of this phenomenon since the 1960s, and more detailed theories and experiments suggest that banding might not occur in chemically inert polymers (such as polystyrene), but is possible in 'living' polymers. Experiments show clear shear banding in living polymers (such as wormlike micelle solutions), but the evidence is poor for chemically inert polymers, except for possibly polymer solutions. I will (1) show computer simulations of entangled polymers that show evidence for shear banding; (2) present a newly realized two-dimensional instability that may render the high shear rate band of banding wormlike micelles (and polymers) to be in an elastic turbulent state; and (3) speculate on why banding is not seen experimentally for simple polymer melts such as polystyrene.

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Dr. Peter Olmsted received an A.B. in Physics from Cornell (1984); and a Ph.D. in Physics from the University of Illinois at Urbana-Champaign (1991), where he studied the theory of liquid crystal hydrodynamics and non-equilibrium phase transitions. Following post-docs at Exxon, Cambridge, and the University of Michigan, where he worked on the theory of a variety of different soft materials (microrheology, membrane dynamics, polymer phase separation, biophysics, liquid crystals, and liquid crystalline elastomers), he moved to Leeds in 1996 for a University Research Fellowship. He became a Professor in 2005 and led the Soft Matter Physics group in Leeds from 2008–2013. While in the UK he was in several European Union networks on Soft Matter and led the EU Integrated Training Network DYNACOP (Dynamics of Architecturally Complex Fluids) from 2008–2012. In 2014 he moved to Georgetown University in Washington, D.C., as Joseph Semmes Ives Chair in Physics, where he joined the Institute for Soft Matter Synthesis and Metrology (ISM2), where he was Director from 2015–2021. He was the Secretary/Treasurer of the APS Topical Group on Soft Matter (DSOFT) from 2014 to 2018. Olmsted is a Fellow of the Institute of Physics (UK), the American Physical Society (Division of Polymer Physics), and the Society of Rheology, and he was awarded the British Society of Rheology Annual Award in 2008. His research achievements include models for polymer crystallization at rest and under flow, theories for shear banding in complex fluids such as polymer and surfactants, an experimental–computational collaboration that revealed how mechanical force unfolds proteins, and recent work on polymer dynamics and disentanglement during additive manufacturing.

Kourosh Shoele

Associate Professor, Department of Mechanical and Aerospace Engineering
Florida State University

Geometrical methods in the theory and computation of fluid–structure interactions

November 6, 2025

Structures immersed in fluid flow inevitably undergo flow-induced forces and vibrations. Traditionally, engineering designs meticulously avoid detrimental flow-induced instabilities such as buckling and flutter. However, in modern engineering applications, these instabilities can be leveraged to reach a higher level of performance. Here, I will present new theoretical and computational models developed to better understand the interaction between fluids and structures. I will begin by establishing connections among seemingly diverse responses of engineering systems in which fluid–structure interaction and interfacial dynamics play central roles. I will then discuss the use of geometrical techniques for flow control in morphing bodies and for quantifying turbulent flow interactions with tree canopies. In this context, I will introduce the embedded geometrical immersion technique for analyzing morphing bodies and describe the formulation of a fast, linearized, model-based flow control framework for shape-changing systems. Finally, I will discuss fluid interactions within fractal, flexible canopies and outline our approach to bridging scales in turbulent flows over tree canopies, as well as identifying large coherent structures within these complex systems.

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Dr. Kourosh Shoele is an Associate Professor of Mechanical and Aerospace Engineering at Florida State University and the Director of the Computational Engineering Initiative at the FAMU-FSU College of Engineering. His research focuses on fluid–structure interaction, model reduction techniques, multiphase flows, and unsteady vortex dynamics. Before joining Florida State University, Dr. Shoele was a Research Scientist at Johns Hopkins University. He earned his Ph.D. from the University of California, San Diego. He is a recipient of the NSF CAREER Award, the DARPA Young Faculty Award, the DARPA Director's Fellowship, and the FSU College of Engineering Rising Star Faculty Award. His research has been supported by the NSF, DARPA, NASA, DOE, ONR, ARO, AFOSR, as well as national laboratories and private industry partners.

Douglas Carter

Assistant Professor, Department of Mechanical, Materials and Aerospace Engineering
Illinois Institute of Technology

Scale-space dynamics of homogeneous turbulence

November 13, 2025

The scale-space framework was originally and infamously used by A. Kolmogorov in 1941 to derive theoretical predictions for the distribution of kinetic energy in homogeneous turbulent flows. Over eighty years later, the scale-space framework continues to bear fruit on this fascinating and challenging topic. In this talk, the instantaneous dynamics that govern the overall cascade of energy and helicity are presented within the scale-space framework, and new insights based on the Lamb decomposition are provided. The mechanics of turbulence energy transfer and how new insights can be translated into useful engineering knowledge will be discussed.

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Dr. Douglas W. Carter is an Assistant Professor in the Department of Mechanical, Materials and Aerospace Engineering at the Illinois Institute of Technology. He earned his bachelor's degree in mechanical engineering from the University of New Hampshire in 2014 and his master's and Ph.D. in aerospace engineering and mechanics from the University of Minnesota in 2017 and 2019, respectively. He held two postdoctoral positions, one at the University of Southampton (UK) and one at Sandia National Laboratories before he was appointed to his current role at Illinois Tech in August of 2024. His research interests encompass all experimental turbulent flows with recent emphasis on high-speed facilities and laser-based diagnostics.

Xiang Yang

Kenneth K. & Olivia J. Kuo Early Career Professor, Department of Mechanical Engineering
Pennsylvania State University

The engineering turbulence problem and a log(Re) data-driven multi-fidelity solution

November 20, 2025

In fluid engineering, the turbulence problem often refers to the challenge of achieving cost-effective yet accurate predictions of engineering quantities such as drag and lift. Existing computational solutions to the turbulence problem represent various levels of compromise between accuracy and computational expense. Computational complexity analysis dictates that practical solutions to the engineering turbulence problem must have a cost scaling no worse than a polynomial function of log(Re). To that end, we propose a multi-fidelity, physics-constrained, data-driven framework that achieves high-fidelity accuracy at a nominal cost scaling of log(Re). The framework consists of: (i) a high-fidelity imulation conducted at a fixed, low Reynolds number, (ii) physics-constrained field inversion and machine learning (FIML) to recalibrate a low-fidelity model against the high-fidelity data at the low Reynolds number, and (iii) application of the augmented low-fidelity model at high Reynolds numbers.

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Dr. Xiang Yang is the Kenneth K. & Olivia J. Kuo Early Career Professor in the Department of Mechanical Engineering at Pennsylvania State University. He received his Ph.D. in Mechanical Engineering from Johns Hopkins University in 2016. Following his Ph.D., Dr. Yang was a Postdoctoral Research Fellow at the Center for Turbulence Research at Stanford University. He joined the Penn State Mechanical Engineering faculty in 2018, where he has continued his research in turbulence and computational fluid dynamics.

Dr. Yang was awarded the American Physical Society Division of Fluid Dynamics Best Thesis Award in 2017 and the Air Force Office of Scientific Research Young Investigator Award in 2022. His research focuses on high-fidelity simulations of turbulent flows, turbulence modeling that bridges physics and data, and the development of ext-generation turbulence theories. He has authored or co-authored over 100 journal articles, and serves as an associate editor for the Journal of Fluids Engineering, Acta Mechanica Sinica, and Theoretical and Applied Mechanics Letters.

Alexandre da Silva

Professor, Department of Mechanical Engineering
Universidade Federal de Santa Catarina

Exploiting complex heat transfer phenomena: Supercritical working fluids and machines that learn boiling

December 4, 2025

This talk will present two key research directions pursued by Dr. da Silva's group at the Laboratory of Energy Conversion Engineering and Energy Technology (LEPTEN), part of the Department of Mechanical Engineering at the Federal University of Santa Catarina (Brazil). The first part will focus on supercritical fluids and their role in energy systems. The talk will examine how the Widom line—a thermodynamic region where the thermo-physical properties of common supercritical heat-transfer fluids vary sharply—relates to the optimal operating conditions of thermal systems. The second part will highlight the group's work on machine learning and computer vision applied to phase-change processes. It will be shown that even simple, non-optimized neural networks can classify instantaneous boiling regimes, detect the onset of the boiling crisis, and estimate heat flux directly from visual data, using only low-speed, low-resolution frames.

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Dr. Alexandre da Silva is currently a tenured faculty at the Federal University of Santa Catarina (UFSC), Brazil. He holds a B.S. ('98) and an M.Sc. ('01), both in Mechanical Engineering from UFSC, and a Ph.D. ('05) in Mechanical Engineering from Duke University (USA). His research interests are in the vast area of theoretical and experimental transport phenomena, including renewable energy systems. His research has been funded by several agencies in the USA (e.g., NSF-CAREER, ARPA-E, ARP-THECB) and Brazil (e.g., CNPq, Petrobras, FINEP, AEB). He is a fellow of the American Society of Mechanical Engineers (ASME), a full member of the Pan American Academy of Engineering, a Scientific Council Member of the International Centre for Heat and Mass Transfer (ICHMT) and the leading scientist of the Baseline Surface Radiation Network (BSRN) station FLO-3. Dr. da Silva has published over 110 peer-reviewed journal articles and served as a reviewer for over 50 peer-reviewed periodicals, advised/co-advised more than 40 graduate students and has received the ABCM-Embraer award twice from the Brazilian Association of Engineering and Mechanical Sciences for having advised the best B.S. and M.S. theses in mechanical engineering in Brazil in '15 and '18, respectively, and shared the Inventor Award from Petrobras ('23). He is also the Associate Editor for Solar Compass and the Editor of AI Thermal Fluids, both from Elsevier. On a personal note, Dr. da Silva is passionate about endurance sports (triathlon). Over the past five years, he completed multiple races, including a full distance Ironman.

Garett Warner

Doctoral Candidate, Department of Meteorology and Atmospheric Science
Pennsylvania State University

Where is the updraft? The influence of heterogeneous surface heating on organized vertical motions within and above a sheared, unstable atmospheric boundary layer

December 11, 2025

Large-eddy simulation (LES) runs are performed to understand the influence of a one-dimensional (1D) surface heating heterogeneity on organized vertical motions within and above the atmospheric boundary layer (ABL). Two knowledge gaps are of interest: i) how updrafts develop in the low free troposphere, and ii) what parameters control updraft location and strength within the ABL? LES runs are performed for a sheared, unstable ABL driven by geostrophic winds of the same magnitude but in various directions relative to a 1D surface-heat-flux heterogeneity. Quasi-steady-state LES results are phase-averaged over time and the horizontal dimension perpendicular to the surface-heat-flux gradient to quantify secondary circulations. Regarding the first knowledge gap, results show that organized vertical motions in the low free troposphere can be modeled as two-dimensional (2D), stationary gravity waves, whose amplitudes depend on ABL updraft strength and instability development within the free troposphere. For the second gap, results show that organized updrafts within the ABL may form above warm surfaces or downwind of warm-to-cool transitions. These different locations are well explained by both the relative contributions of horizontal and vertical velocities to the phase-averaged vorticity fluctuations tied to secondary circulations, and the relative importance of horizontal advection and turbulent transport in the phase-averaged internal energy fluctuation equation. The main balances associated with each updraft location are used to propose empirical models of updraft strength, and it is shown that the presence of sufficiently strong organized vertical motions can potentially change parameters used by atmospheric models that do not resolve ABL turbulence.

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Mr. Garett R. T. Warner is a Ph.D. candidate in Meteorology and Atmospheric Science at The Pennsylvania State University, where his research focuses on atmospheric turbulence, boundary-layer processes, and shallow convection. Using LES, his work examines how heterogeneous surface heating through cloud–surface–radiation feedbacks affects shallow convective currents such as horizontal convective rolls. His recent studies have advanced understanding of the dimensionless parameters governing updraft location and strength in the presence of heterogeneous surface heating, with results published in the Journal of the Atmospheric Sciences. Current research focuses on quantifying the spatial characteristics of horizontal convective rolls and assessing how nonsteady surface heating influences the spacing and alignment of their updrafts. Garett has presented his research at national conferences, including meetings of the American Meteorological Society and the American Geophysical Union.