BEGIN:VCALENDAR VERSION:2.0 PRODID:-//galcit.divisions.caltech.edu//Events//EN CALSCALE:GREGORIAN METHOD:PUBLISH X-WR-CALNAME:Caltech events: https://aerospace.caltech.edu/events/seminars /ical X-WR-TIMEZONE:America/Los_Angeles BEGIN:VTIMEZONE TZID:America/Los_Angeles LAST-MODIFIED:20230407T050750Z TZURL:https://www.tzurl.org/zoneinfo-outlook/America/Los_Angeles X-LIC-LOCATION:America/Los_Angeles BEGIN:DAYLIGHT TZNAME:PDT TZOFFSETFROM:-0800 TZOFFSETTO:-0700 DTSTART:19700308T020000 RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU END:DAYLIGHT BEGIN:STANDARD TZNAME:PST TZOFFSETFROM:-0700 TZOFFSETTO:-0800 DTSTART:19701101T020000 RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU END:STANDARD END:VTIMEZONE BEGIN:VEVENT SUMMARY:Mud flocculation and the global sediment cycle DTSTART;TZID=America/Los_Angeles:20251003T150000 DTEND;TZID=America/Los_Angeles:20251003T160000 DTSTAMP:20260416T225443Z UID:GALCIT Colloquium@Fri Oct 3 15:00:00 2025@galcit.divisions.caltech.ed u CATEGORIES: DESCRIPTION:Michael Lamb\, Professor\, Geology\, California Institute of T echnology\n River sediment loads are dominated by mud\, which builds lowla nd and coastal landscapes and buries large amounts of organic carbon. Whil e mechanistic theories exist for transport of suspended sand\, mud in rive rs is often thought to constitute washload—sediment with settling rates so slow that it does not interact with the land surface. The washload hypo thesis\, however\, is seemingly at odds with the muddy terrain that abound s globally. Here I summarize recent work by our group to show that mud in many rivers is flocculated with settling velocities much larger than expec ted for individual particles. Flocculation allows mud to interact with and deposit on the land. Our results help to explain why muddy landscapes exi st today\, why they were less abundant early in Earth history\, and why an thropogenic disruption of the global sediment cycle is causing major unint ended land loss. LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/galcit-colloquium-385 END:VEVENT BEGIN:VEVENT SUMMARY:Understanding Thermo-Chemo-Mechanical Failure in Hypersonic Flight through Large-Scale Simulation DTSTART;TZID=America/Los_Angeles:20251008T160000 DTEND;TZID=America/Los_Angeles:20251008T170000 DTSTAMP:20260416T225443Z UID:Aerospace Department - EAS Trailblazers Seminar@Wed Oct 8 16:00:00 20 25@galcit.divisions.caltech.edu CATEGORIES: DESCRIPTION:Daniel Pickard\, Institute for Soldier Nanotechnologies\, Mass achusetts Institute of Technology\, Cambridge\, MA. Department of Aeronau tics and Astronautics\, Massachusetts Institute of Technology.\nAbstractMa terials and structures subjected to the extreme conditions of hypersonic f light undergo complex thermochemical degradation and fracture. Understandi ng and predicting these effects is critical for low-cost\, sustainable spa ce access and various scientific\, industrial and national security object ives. We elucidate the fundamental mechanisms governing both ceramic and a blative thermal protection systems using a theoretical formulation and lar ge-scale simulation framework for fracturing solids with complex post-frac ture thermochemical response. First\, a computational model of recently ob served thermal shock and pore pressure failures is used to explore key fai lure modes and potential damage mitigation strategies. Then\, a rigorous c onstitutive theory is shown to capture molecular diffusion through passive ly oxidizing ultra-high temperature ceramics. Three-dimensional coating si mulations expose the channeling mechanisms and a transition from decussati ng to circumferential cracking that explains the rich variety of surface c racks found in experiments. We corroborate the distinct fracture morpholog y regimes using a simple structural theory and conclude with exciting aven ues for future research.BiographyDaniel Pickard is a postdoctoral research er in the Department of Aeronautics and Astronautics at the Massachusetts Institute of Technology. He received undergraduate\, masters and doctoral degrees in the same department in 2020\, 2022\, and 2025. His research is concerned with highfidelity simulation of multiphysics phenomena in solid materials. With his collaborators\, he is developing numerical methods to advance our understanding of the physical effects of highenthalpy hyperson ic flows on reentry vehicle thermal protection systems. Dr. Pickard enjoys teaching computational mechanics and learning about new developments in r elated areas. LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/aerospace-department-eas -trailblazers-seminar-1 END:VEVENT BEGIN:VEVENT SUMMARY:The fluid-structure interaction of nanoparticles DTSTART;TZID=America/Los_Angeles:20251010T150000 DTEND;TZID=America/Los_Angeles:20251010T160000 DTSTAMP:20260416T225443Z UID:GALCIT Colloquium@Fri Oct 10 15:00:00 2025@galcit.divisions.caltech.ed u CATEGORIES: DESCRIPTION:John Sader\, Research Professor\, Aerospace & Applied Physics\ , California Institute of Technology\nAn understanding of the fluid-struct ure interaction of nanoparticles in Newtonian and non-Newtonian fluids is fundamental to many applications. In this talk\, I will discuss three topi cs that explore this interaction: (1) the propulsion of nanoparticles imme rsed in an acoustic field\; (2) use of the resonance properties of nanopar ticles to interrogate the viscoelasticity of simple liquids\; and (3) the induced motion of nanoparticles within resonant microfluidic devices. LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/galcit-colloquium-386 END:VEVENT BEGIN:VEVENT SUMMARY:Making robots trustworthy: Understanding risk and uncertainty for safe autonomy DTSTART;TZID=America/Los_Angeles:20251024T150000 DTEND;TZID=America/Los_Angeles:20251024T160000 DTSTAMP:20260416T225443Z UID:GALCIT Colloquium@Fri Oct 24 15:00:00 2025@galcit.divisions.caltech.ed u CATEGORIES: DESCRIPTION:Anushri Dixit\, Assistant Professor\, Mechanical and Aerospace Engineering\, University of California\, Los Angeles\n As we deploy robot s in increasingly dynamic and unstructured environments with data-driven p olicies\, the need to be able to make guarantees on the reliability and sa fety of these systems keeps growing. In this talk\, I will present two per spectives on uncertainty quantification. First\, I will present a conforma l prediction-based framework for making in-distribution guarantees on the safety of a learned perception and planning system. Next\, I will present a risk-aware reinforcement learning framework for quadrupedal locomotion t hat adapts to out-of-distribution scenarios. I will provide the experiment al validation of these methods on ground robots for navigation that are in spired by applications for subterranean search and rescue. Finally\, I wil l present future directions and challenges in attaining reliable autonomy under distribution shifts. LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/galcit-colloquium-391 END:VEVENT BEGIN:VEVENT SUMMARY:Experiments on passive-scalar high Schmidt number dispersion in gr id turbulence DTSTART;TZID=America/Los_Angeles:20251107T150000 DTEND;TZID=America/Los_Angeles:20251107T160000 DTSTAMP:20260416T225443Z UID:GALCIT Colloquium@Fri Nov 7 15:00:00 2025@galcit.divisions.caltech.ed u CATEGORIES: DESCRIPTION:Paul Dimotakis\, John K. Northrop Professor\, Aeronautics and Professor of Applied Physics\, California Institute of Technology\nThe tal k will be on the development of experimental measurement and data-processi ng methodologies based on planar laser-induced fluorescence (PLIF) and oth er diagnostic techniques\, in collaboration with Daniel Lang. The experime nts investigated the downstream transport\, dispersion\, diffusion\, and m ixing of a miscible passive scalar from a point-release in grid-turbulence at high Schmidt number. The scalar plumes developed downstream in uniform -density (unstratified) turbulent flow formed by a grid towed in a tank th rough otherwise stationary water. PLIF image data were processed to calibr ate and correct for local variations in gains and offsets over pixels of a custom-designed and fabricated charged-coupled device (CCD) focal-plane i mage sensor. Data were acquired using illumination from a quad-head pulsed Nd:YAG laser\, at pulse rates up to 200 Hz\, and recorded by means of a c ustom-designed and built data-acquisition system. The optical system gener ated and imaged laser-sheet 2-D streamwise transects\, individual 2-D tran sverse transects\, or 2-D transverse transects swept in a direction perpen dicular to their plane. Concentration data were processed to extract quant itative flow and scalar-field visualization\, and quantitative turbulent-p lume statistics\, such as mean plume profiles\, spatial transverse radial and streamwise scalar spectra\, and other information\, over a range of me sh Reynolds numbers and downstream distances from the grid\, with variable scalar-injection-speed to flow-speed ratios. Preliminary processed sample data illustrate the application of the experimental method and the result ing measurement dynamic range\, as required to discern far-field downstrea m behavior of the scalar plume. LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/galcit-colloquium-387 END:VEVENT BEGIN:VEVENT SUMMARY:GALCIT Colloquium DTSTART;TZID=America/Los_Angeles:20251114T150000 DTEND;TZID=America/Los_Angeles:20251114T160000 DTSTAMP:20260416T225443Z UID:GALCIT Colloquium@Fri Nov 14 15:00:00 2025@galcit.divisions.caltech.ed u CATEGORIES: DESCRIPTION:Andres Goza\, Assistant Professor\, Aerospace Engineering\, Un iversity of Illinois Urbana-Champaign\n LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/galcit-colloquium-388 END:VEVENT BEGIN:VEVENT SUMMARY:Unmanned vehicles in realistic flows: fluid-structure interaction and non-equilibrium effects DTSTART;TZID=America/Los_Angeles:20251121T150000 DTEND;TZID=America/Los_Angeles:20251121T160000 DTSTAMP:20260416T225443Z UID:GALCIT Colloquium@Fri Nov 21 15:00:00 2025@galcit.divisions.caltech.ed u CATEGORIES: DESCRIPTION:Gonzalo Arranz Fernandez\, Postdoctoral Associate in Aerospace \, GALCIT\, California Institute of Technology\n\nUnmanned aerial and unde rwater vehicles operating in real-world conditions must navigate complex e nvironments\, requiring understanding of flow interactions across vastly d ifferent scales. This talk presents two complementary approaches to this c hallenge. We first examine tandem configurations of self-propelled flexibl e flappers in controlled conditions through direct numerical simulation\, revealing how hydrodynamic interactions between bodies determine collectiv e performance. By systematically analyzing vortex-wake interactions\, we i dentify scaling laws and reduced-order models that capture the essential p hysics of flow-mediated coupling. In turbulent environments\, by contrast\ , the complexity of flow-mediated interactions makes systematic analysis o f all possible effects intractable. In these complex regimes\, we must ide ntify which flow features govern performance and which can be neglected. T he second part of the talk addresses how to systematically identify these governing parameters. We employ an information-theoretic framework to disc over optimal scaling laws directly from data in non-equilibrium turbulent boundary layers subjected to favorable and adverse pressure gradients\, in cluding separation. This data-driven methodology reveals the non-dimension al groups that capture the essential physics needed to predict average flo w quantities in non-equilibrium flows. LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/galcit-colloquium-392 END:VEVENT BEGIN:VEVENT SUMMARY:Title: Simple Mechanics for Life-Saving Technologies: Milli-Spinne r Thrombectomy for Stroke Treatment DTSTART;TZID=America/Los_Angeles:20251205T150000 DTEND;TZID=America/Los_Angeles:20251205T160000 DTSTAMP:20260416T225443Z UID:GALCIT Colloquium@Fri Dec 5 15:00:00 2025@galcit.divisions.caltech.ed u CATEGORIES: DESCRIPTION:Renee Zhao\, Assistant Professor\, Mechanical Engineering\, St anford University\nMillimeter-scale robots hold great promise for biomedic al applications due to their remarkable shape-morphing capabilities. In th is talk\, I will present our recent advancements in millimeter-sized robot s designed for medical applications. These robots leverage their thin-shel l structures to enable a range of functionalities: 1) Providing internal c avities for drug storage\; 2) Utilizing torsion-induced contraction as a p umping mechanism for controlled liquid medicine dispensing\; 3) Acting as propellers that spin for propulsion to swim\, exemplified by a device we c all the milli-spinner.As an example\, I will highlight our recent developm ent of the magnetic milli-spinner as a mechanical thrombectomy technology for treating acute ischemic stroke and brain aneurysms. The milli-spinner can easily navigate in complex and highly torturous vasculature\, mechanic ally debulk and extract blood clots by significantly densifying the fibrin network\, achieving a clot volume reduction to less than 10% of its initi al size. This new clot debulking mechanism has demonstrated exceptional ef ficacy in both in vitro and in vivo pig studies.In the second part of my t alk\, I will briefly explore how structural instability can be harnessed t o create new functional origami designs for a variety of engineering appli cations LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/galcit-colloquium-389 END:VEVENT BEGIN:VEVENT SUMMARY:Emergent Functionality Through 3D Architected Electronic Materials DTSTART;TZID=America/Los_Angeles:20260109T150000 DTEND;TZID=America/Los_Angeles:20260109T160000 DTSTAMP:20260416T225443Z UID:Aerospace Colloquium@Fri Jan 9 15:00:00 2026@galcit.divisions.caltech .edu CATEGORIES: DESCRIPTION:Xiaoyu Zheng\, Associate Professor\, Materials Science and Eng ineering\, Berkeley\nAdvanced fabrication and manufacturing are expanding the design space for multi-scale features and intricate three-dimensional architectures. Yet\, the direct co-fabrication of structural\, dielectric\ , conductive\, and active media remains a core challenge—particularly fo r systems that must sense\, actuate\, and adapt to electrical\, acoustic\, or mechanical stimuli. Unlike biological tissues\, which intrinsically in tegrate sensing\, actuation\, and control\, synthetic materials rarely ach ieve comparable system-level functionality.In this talk\, I will present n ew multi-material additive manufacturing strategies that enable high-speed \, compositionally precise assembly of diverse material classes within 3D architectures. These approaches access behaviors beyond conventional const itutive limits\, including symmetry-breaking piezoelectric effects\, elect ro-acoustic coupling\, and new toughening mechanisms that emerge only in m ulti-material form.The resulting "intelligent solids" embed sensing\, actu ation\, and signal transduction directly into their structure. I will high light their application in robotic tactile sensing\, autonomous path findi ng\, and real-time texture recognition at the scale of a human fingertip. This platform offers near-neural-terminal resolution in recording and tran smitting distributed tactile information for robotic grippers\, surgical t ools\, wearable interfaces\, and remote systems. These engineered material s localize contact\, measure three-axis forces\, and generate programmable haptic responses—functioning as artificial mechanoreceptors and pointin g toward a new class of embodied\, adaptive matter. LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/galcit-colloquium-393 END:VEVENT BEGIN:VEVENT SUMMARY:The Physics of Purposeful Biological Dynamics DTSTART;TZID=America/Los_Angeles:20260116T150000 DTEND;TZID=America/Los_Angeles:20260116T160000 DTSTAMP:20260416T225443Z UID:Aerospace Colloquium@Fri Jan 16 15:00:00 2026@galcit.divisions.caltech .edu CATEGORIES: DESCRIPTION:Rob Phillips\, Professor\, Division of Biology and Biological Engineering\, California Institute of Technology\nTime and again since the era of Newton\, physics has come forthwith new classes of dynamical laws ranging from Fourier's mastery ofthe heat equation to Maxwell's theory of the electromagnetic field to Turing's ideason pattern formation and many o thers.  \;However\, there are a large class ofdynamical processes in l iving organisms where the mechanicaldescription is of a completely differe nt kind.In particular\, many biological processes are exploratory in natur e\, often largely independent ofinitial conditions\, and driven by a funct ional purpose.  \;For example\, before ourcells divide\, precisely 46 connections have to be made between the machinerythat separates chromosome s and the chromosomes themselves.  \;Not 45\, not 47.One connection fo r every one of our 23 pairs of chromosomes.  \; In this talk\, I will describethe hypothesis of exploratory dynamics as biology's unique and nec essary solutionto problems in purposeful dynamics.  \;After introducin g the conceptual questions and \;corresponding phenomenological observ ations\, I will describe both theoreticalapproaches to thinking about expl oratory dynamics and experiments designed to \;reveal its many quantit ative mysteries. LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/aerospace-colloquium-1 END:VEVENT BEGIN:VEVENT SUMMARY:Fluid Mechanics of the Dead Sea: Rise of the Salt Giants DTSTART;TZID=America/Los_Angeles:20260123T150000 DTEND;TZID=America/Los_Angeles:20260123T160000 DTSTAMP:20260416T225443Z UID:Aerospace Colloquium@Fri Jan 23 15:00:00 2026@galcit.divisions.caltech .edu CATEGORIES: DESCRIPTION:Eckart Meiburg\, Professor\, Mechanical Engineering\, Universi ty of California Santa Barbara\nThe environmental setting of the Dead Sea combines several aspects whose interplay creates flow phenomena and transp ort processes that cannot be observed anywhere else on Earth. As a termina l lake with a rapidly declining surface level\, the Dead Sea has a salinit y level that is close to saturation\, so that the buoyancy-driven flows co mmon in lakes are coupled to precipitation and dissolution\, and large amo unts of salt are being deposited year-round. This provides an opportunity to investigate the formation of "salt giants\," large-scale salt deposits that are observed to have formed in Earth's crust around the world. The De ad Sea is the only hypersaline lake deep enough to form a significant ther mohaline stratification during the summer\, which gives rise to descending supersaturated dissolved-salt fingers that precipitate halite particles. In contrast\, during the winter the entire supersaturated\, well-mixed wat er column produces halite. The rapid lake level decline of O(1m/year) expo ses vast areas of newly formed beach every year\, which exhibit deep incis ions from streams. Taken together\, these phenomena provide insight into t he enigmatic salt giants observed in the Earth's geological record and off er lessons regarding the stability\, erosion\, and protection of arid coas tlines under sea level change. LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/galcit-colloquium-394 END:VEVENT BEGIN:VEVENT SUMMARY:The Separation Aerodynamics of Idealized Fragmenting Meteoroids DTSTART;TZID=America/Los_Angeles:20260130T150000 DTEND;TZID=America/Los_Angeles:20260130T160000 DTSTAMP:20260416T225443Z UID:Aerospace Colloquium@Fri Jan 30 15:00:00 2026@galcit.divisions.caltech .edu CATEGORIES: DESCRIPTION:Stuart Laurence\, Professor\, Aerospace Engineering\, Universi ty of Maryland\, College Park\nFor a meteoroid undergoing break-up within the atmosphere\, the high-speed aerodynamic interactions between fragments immediately following disruption play a critical role in determining the risks posed at the terrestrial surface. In this seminar\, I will first des cribe experimental\, computational\, and theoretical studies of the intera ctions between two isolated bodies as a basis for understanding the more g eneral separation problem\, highlighting the importance of "shock surfing" \, where one body rides the shock of the other body downstream. I will the n describe recent experiments in a hypersonic wind tunnel to determine the separation characteristics of an idealized fragmented meteoroid\, consist ing of an initially spherical cluster of up to 115 close-packed spherical bodies. For equal-sized fragments\, the mean separation velocity follows a power law as a function of population with an exponent of ~0.4\, while in dividual velocities are well-modeled by a single-parameter Rayleigh distri bution. In unequal clusters\, mass retention in sub-clusters decreases the mean separation velocity\, but individual velocities again follow approxi mate Rayleigh distributions (with the governing parameter now radius-depen dent). An examination of the most ejected bodies in the dataset also revea ls that shock surfing can produce significant outliers and potentially exp lain a substantial portion of the discrepancy between airburst observation s and previous predictions. LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/galcit-colloquium-395 END:VEVENT BEGIN:VEVENT SUMMARY:Prediction and Control of Transverse Jet Shear Layer Instabilities DTSTART;TZID=America/Los_Angeles:20260206T150000 DTEND;TZID=America/Los_Angeles:20260206T160000 DTSTAMP:20260416T225443Z UID:Aerospace Colloquium@Fri Feb 6 15:00:00 2026@galcit.divisions.caltech .edu CATEGORIES: DESCRIPTION:Ann Karagozian\, Professor\, Mechanical & Aerospace Engineerin g\, University of California\, Los Angeles\nComplex flow phenomena are pre sent in fluid flow systems underlying energy generation and propulsion\, a nd control of such fundamental phenomena is key to development of efficien t\, robust systems. This talk will describe research at UCLA on flow insta bilities and their control\, in the spirit of this fundamental approach\, with a focus on the canonical jet in crossflow (JICF) or transverse jet. N ew insights into JICF shear layer stability characteristics have created t he potential for tailored flow control which can alter jet dynamics\, mole cular mixing and other important features of the jet flow. Quantification and interrogation of the flowfield involves use of acetone planar laser-in duced fluorescence (PLIF) imaging and simultaneous stereo particle image v elocimetry (PIV)\, with dynamical characteristics documented via Proper Or thogonal Decomposition (POD) analysis. Transitions in shear layer instabil ities from convective to absolute to global instability are observed to de pend on specific flow conditions\, with attendant alterations in jet struc ture and symmetry that can have a significant effect on mixing metrics. Th ese fundamental stability characteristics require alternative methods for reduced order model development as well as jet control\, depending on the flow regime\, which can optimize performance of the jet in various applica tions. LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/galcit-colloquium-396 END:VEVENT BEGIN:VEVENT SUMMARY:Mechanics and Materials for Extreme Propulsion: Tuning Micro-Parti cle Impacts using Novel High Throughput Dynamic Experiments DTSTART;TZID=America/Los_Angeles:20260213T150000 DTEND;TZID=America/Los_Angeles:20260213T160000 DTSTAMP:20260416T225443Z UID:Aerospace Colloquium@Fri Feb 13 15:00:00 2026@galcit.divisions.caltech .edu CATEGORIES: DESCRIPTION:Suhas Eswarappa Prameela\, Assistant Professor\, Metallurgical Engineering\, University of Utah\nThe performance of next-generation prop ulsion systems is defined by materials that must withstand complex\, coupl ed extreme environments. In this talk\, I will present two case studies in which micron-scale particles are accelerated to high velocities to invest igate supersonic bonding during cold spray additive manufacturing and part icle impact damage arising from plume–surface interactions during lunar missions. This work is enabled by a novel high-throughput experimental pla tform called Laser-Induced Projectile Impact Testing (LIPIT)\, which launc hes individual micro-projectiles at controlled subsonic to supersonic velo cities and combines nano-temporal high-speed imaging with quantitative pos t-mortem microscopy characterization. Supersonic bonding experiments on co ated and uncoated GRX-810 alloys used in NASA propulsion systems introduce the Oxide Connectivity Index (OCI)\, a quantitative metric linking fragme nted oxide networks with enhanced adhesion and continuous oxide layers wit h suppressed bonding. In parallel\, LIPIT-based studies of regolith partic le impacts reveal distinct fragmentation thresholds and damage mechanisms relevant to propulsion hardware during Moon landings. LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/galcit-colloquium-397 END:VEVENT BEGIN:VEVENT SUMMARY:Manipulating Spectral Energy Flux in Turbulent Flows: Applications and Implications Across Scales DTSTART;TZID=America/Los_Angeles:20260220T150000 DTEND;TZID=America/Los_Angeles:20260220T160000 DTSTAMP:20260416T225443Z UID:Aerospace Colloquium@Fri Feb 20 15:00:00 2026@galcit.divisions.caltech .edu CATEGORIES: DESCRIPTION:Lei Fang\, Assistant Professor\, Civil and Environmental Engin eering\, University of Pittsburgh\nIn turbulent flows\, energy flux refers to the transfer of kinetic energy across different scales of motion\, a c oncept that is a cornerstone of turbulence theory. The direction of net en ergy flux is prescribed by the dimensionality of the fluid system. Accordi ng to Kolmogorov's 1941 scaling theory\, three-dimensional turbulence has a net energy flux toward smaller length scales\, while in two-dimensional turbulence\, energy transfers toward larger scales\, as described in Kraic hnan and Batchelor's seminal works. Manipulating energy flux across differ ent scales with localized physical perturbations in flow systems is a form idable task because the energy at any scale is not localized in physical s pace. In this talk\, I will present a theoretical framework that enables t he manipulation of energy flux direction in turbulent flows. Based on this framework\, we have successfully demonstrated the manipulation of a flow system to achieve the desired directions of net energy flux through both e lectromagnetically driven thin-layer flow experiments and direct numerical simulations in two dimensions. Notably\, we generated a type of turbulent flow that has never been produced before—two-dimensional Navier-Stokes turbulence with a net forward energy flux. Beyond theoretical interest\, w e will discuss how our theoretical framework can have profound application s and implications across natural and engineered systems. First\, at the c entimeter scale\, it predicts—and we experimentally confirm—that spect ral energy flux in quasi-two-dimensional flows can be enhanced by up to tw o orders of magnitude around a Reynolds number of order unity (defined bas ed on linear friction). Second\, at the meter scale\, the framework reveal s that there is no universal minimum body size required for swimmers to ge nerate appreciable biogenic turbulence\; rather\, such turbulence depends jointly on organism size\, the ambient flow\, as well as their geometric a lignment. Third\, at submesoscale\, we demonstrate that small-scale bounda ries—three orders of magnitude smaller than the oceanic transport barrie r itself—can be used to disrupt and modulate transport barriers\, offeri ng a new pathway for low-energy control of large-scale material exchange. LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/galcit-colloquium-398 END:VEVENT BEGIN:VEVENT SUMMARY:How to Improve the Performance of an Airtanker Drop DTSTART;TZID=America/Los_Angeles:20260226T160000 DTEND;TZID=America/Los_Angeles:20260226T170000 DTSTAMP:20260416T225443Z UID:Theodore Y. Wu and Chin-Hua Wu Lecture@Thu Feb 26 16:00:00 2026@galcit .divisions.caltech.edu CATEGORIES: DESCRIPTION:Dominique Legendre\, Professor\, Fluid Mechanics\, Toulouse IN P\, National Polytechnic Institute of Toulouse\nTitle: "How to Improve the Performance of an Airtanker Drop"Abstract: Airtanker firefighting is a fa scinating tool used to fight wildland fires. Airtankers are\, however\, de veloped based on empirical methods\, and their performance is only discove red after drop tests made above a grid of cups distributed on a flat field with no vegetation (the cup &\; grid method)\, developed during the 19 90s. Dropping a liquid from an aircraft seems easy to achieve because the released liquid directly falls to the ground due to gravity. However\, the fluid dynamics processes that govern this practice are characterized by r ich and varied physical phenomena\, and controlling the resulting fluid di stribution of the drop pattern raises many scientific issues.The liquid co lumn penetration in the air\, its large-scale fragmentation\, and an inten se surface atomization give shape to the rainfall produced by the airtanke r and the final product deposition onto the canopy. The respective roles o f these mechanisms are described and analyzed here in order to determine t he parameters of importance for improving airtanker drop performance for m ore efficient firefighting.Bio: Prof. Dominique Legendre graduated with a PhD in Fluid Mechanics from Toulouse INP\, France\, in 1996. He has been a Professor of Fluid Mechanics at Toulouse INP since 2007\, and he is Deput y Director of IMFT (Institut de Mécanique des Fluides de Toulouse)\, one of the leading fluid mechanics institutes in Europe. He has been Chairman of the Governing Board of the International Conference on Multiphase Flows (ICMF) from 2022 to 2025.His main line of research is multiphase flows\, in particular bubble and drop dynamics\, including heat and mass transfer\ , icing\, and wetting phenomena. Over the last decade\, he has developed a n original research program on airtanker firefighting efficiency with a st rong connection to the aerial firefighting industry. In particular\, he ha s developed the NaSCa code to model ground deposits of liquid dropped by a ny aerial system. In 2019\, a patent was granted for a new delivery system \, KIOS\, in collaboration with Kepplair Evolution\, and he is now an expe rt for the KE72 project to transform an ATR72 into an airtanker. He has le d several international publications on the subject\, in particular a cont ribution to the Annual Review of Fluid Mechanics in 2024. In 2023\, in Was hington\, DC\, he delivered an invited keynote lecture on the fluid mechan ics of airtanker firefighting at one of the most prestigious international fluid mechanics conferences (the Annual Meeting of the Division of Fluid Dynamics of the American Physical Society). For all his contributions\, he received the "Transfert Technologique" Award of Toulouse University in 20 22. LOCATION:Gates-Thomas 135 URL:https://aerospace.caltech.edu/events/seminars/mechanical-and-civil-eng ineering-seminar-285 END:VEVENT BEGIN:VEVENT SUMMARY:Aerospace Colloquium DTSTART;TZID=America/Los_Angeles:20260227T150000 DTEND;TZID=America/Los_Angeles:20260227T160000 DTSTAMP:20260416T225443Z UID:Aerospace Colloquium@Fri Feb 27 15:00:00 2026@galcit.divisions.caltech .edu CATEGORIES: DESCRIPTION:Behcet Acikmese\, Professor\, Aeronautics & Astronautics\, Uni versity of Washington\n LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/galcit-colloquium-399 END:VEVENT BEGIN:VEVENT SUMMARY:Aerospace Colloquium DTSTART;TZID=America/Los_Angeles:20260306T150000 DTEND;TZID=America/Los_Angeles:20260306T160000 DTSTAMP:20260416T225443Z UID:Aerospace Colloquium@Fri Mar 6 15:00:00 2026@galcit.divisions.caltech .edu CATEGORIES: DESCRIPTION:Karthik Duraisamy\, Arthur B. Modine Professor\, Aerospace Eng ineering\, University of Michigan\n LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/galcit-colloquium-400 END:VEVENT BEGIN:VEVENT SUMMARY:When waves are important\, what is the best constitutive law for i mpact mitigation and how can we realize it? DTSTART;TZID=America/Los_Angeles:20260403T150000 DTEND;TZID=America/Los_Angeles:20260403T160000 DTSTAMP:20260416T225443Z UID:Aerospace Colloquium@Fri Apr 3 15:00:00 2026@galcit.divisions.caltech .edu CATEGORIES: DESCRIPTION:Nicholas Boechler\, Associate Professor\, Mechanical & Aerospa ce Engineering\, University of California\, San Diego\n Particularly for h igh-speed impacts\, the propagation of mechanical waves\, affected by the properties of the material through which they traverse\, can play a major role in the resulting damage incurred. This raises the question\, in such regimes\, if one could choose any constitutive response for the impacted m aterial\, what is the best? For this talk\, I will summarize our initial s teps towards answering this question. Considering peak kinetic energy as a figure of merit\, we use reduced-order models to study the interplay of: i) bistable elasticity\, viscosity\, and discreteness\; ii) tailorable pol ynomial nonlinear elasticity\; and iii) constitutive heterogeneity. The ob served performance differences raise the further question: how can we real ize materials with an identified optimal constitutive response? I will des cribe our initial steps to answer this latter question via the use of shap e optimization of subwavelength structural motifs. The approaches describe d herein may find future use in impact problems considering different figu res of merit\, energetic regimes\, and physical mechanisms\, as well as di fferent dynamical settings\, unrelated to impact\, potentially even outsid e solid mechanics. LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/galcit-colloquium-401 END:VEVENT BEGIN:VEVENT SUMMARY:Unravelling hydrogen-material interactions: a challenge across sca les and disciplines DTSTART;TZID=America/Los_Angeles:20260410T150000 DTEND;TZID=America/Los_Angeles:20260410T160000 DTSTAMP:20260416T225443Z UID:Aerospace Colloquium@Fri Apr 10 15:00:00 2026@galcit.divisions.caltech .edu CATEGORIES: DESCRIPTION:Emilio Martinez Paneda\, Associate Professor\, Engineering Sci ence\, Oxford University\nThe exposure to small quantities of hydrogen (in the ppm range) can reduce the ductility\, fracture toughness\, and fatigu e crack growth resistance of metals by orders of magnitude. This remarkabl e phenomenon\, so-called ‘hydrogen embrittlement'\, is pervasive across the transport\, defence\, energy and construction sectors\, due to the ubi quitousness of hydrogen\, and constitutes one of the biggest threats to th e future of hydrogen as a clean energy carrier. However\, understanding an d predicting hydrogen-metal interactions have proven to be more difficult than first anticipated. This talk will overview the author's cross-discip linary efforts to shed light on the nature of hydrogen-assisted failures. Focus will be on the combination of experiments and modelling across scale s and disciplines\, to mechanistically resolve the physical processes unde rlying hydrogen embrittlement\, from the (electro-)chemical uptake of hydr ogen from gaseous and aqueous electrolyte environments\, to the diffusion and transport of dissolved hydrogen in the crystal lattice\, and to the hy drogen-assisted nucleation and growth of cracks. The insight gained has le d to the development of a new class of physically-based electro-chemo-mech anical models for hydrogen embrittlement that can not only obtain an unpre cedented level of agreement with laboratory experiments but also deliver f inite element predictions at scales relevant to engineering practice\, bri nging the "Virtual Testing" paradigm to hydrogen-containing environments. Finally\, focus will be placed on a recent\, pressing challenge: with the upcoming use of hydrogen in aviation\, there is a need to understand\, fro m first principles\, the behaviour of metals exposed to hydrogen and extre me environments (temperatures ranging from 20 K to nearly 1800 K). Given t he small margins of the aviation industry\, this requires a new way of thi nking\, whereby every hydrogen-material interaction must be appropriately described (and not fitted)\, from the atom scale\, to the dislocation leve l\, and to the macroscopic component performance\, through a new generatio n of mechanistic quantum-mechanically informed\, thermo-chemo-mechanical c rystal plasticity models. LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/galcit-colloquium-402 END:VEVENT BEGIN:VEVENT SUMMARY:Multiphysics Simulations on GPUs using high-order finite elements DTSTART;TZID=America/Los_Angeles:20260417T150000 DTEND;TZID=America/Los_Angeles:20260417T160000 DTSTAMP:20260416T225443Z UID:Susan and James Wu Aerospace Colloquium@Fri Apr 17 15:00:00 2026@galci t.divisions.caltech.edu CATEGORIES: DESCRIPTION:Robert Rieben\, Computational Physicist\, Lawrence Livermore N ational Laboratory\nLawrence Livermore National Laboratory (LLNL) is devel oping next generation simulation capabilities for exascale computing syste ms as part of the Multiphysics on Advanced Platforms Project (MAPP). One o f the key outcomes of this project is MARBL\, an arbitrary Lagrangian-Eule rian (ALE) multiphysics code that utilizes high-order finite element discr etizations. In this presentation\, we will discuss the finite element meth ods created for ALE multiphysics\, with a focus on "matrix-free" partial a ssembly techniques that allow for scalable and GPU-efficient computation o f high-order finite element operators. We will also outline the multiphysi cs capabilities of MARBL and its applications in modeling inertial confine ment fusion (ICF) and high-energy density physics (HEDP) experiments\, inc luding large-scale GPU simulations on the El Capitan supercomputer. Additi onally\, we will cover recent work applying MARBL to astrophysics simulati ons and conclude with our vision for the future centered on the developmen t of differentiable multiphysics codes. LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/aerospace-colloquium-2 END:VEVENT BEGIN:VEVENT SUMMARY:Aerospace Colloquium DTSTART;TZID=America/Los_Angeles:20260424T150000 DTEND;TZID=America/Los_Angeles:20260424T160000 DTSTAMP:20260416T225443Z UID:Aerospace Colloquium@Fri Apr 24 15:00:00 2026@galcit.divisions.caltech .edu CATEGORIES: DESCRIPTION:Carlos Alejandro Pantano-Rubino\, Professor\, Aerospace and Me chanical Engineering\, University of Southern California\n LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/galcit-colloquium-403 END:VEVENT BEGIN:VEVENT SUMMARY:Hypervelocity Water Entry and Free Flight Experiments DTSTART;TZID=America/Los_Angeles:20260501T150000 DTEND;TZID=America/Los_Angeles:20260501T160000 DTSTAMP:20260416T225443Z UID:Susan and James Wu Aerospace Colloquium@Fri May 1 15:00:00 2026@galci t.divisions.caltech.edu CATEGORIES: DESCRIPTION:Bryan Schmidt\, Assistant Professor\, Mechanical & Aerospace E ngineering\, Case Western Reserve University\nWater entry is a classic his torical problem in fluid mechanics\, and is often one of the first phenome na related to fluids that children encounter\, when they throw stones into a lake or pond. While conceptually simple\, water entry is extremely comp lex and involves air entrainment\, surface tension\, and multiphase flow e ven at low speeds. The situation becomes much more complicated as the proj ectile speed is increased\, as shock waves and cavitation play important r oles. In this seminar\, I will discuss my research group's recent progress investigating water entries at previously un-investigated speeds in exces s of 1.5 km/s\, which is supersonic even in the liquid water. Our approach involves experiments with a two-stage light gas gun facility as well as h igh fidelity simulations although I will focus on the experiments. The tal k will highlight some interesting phenomena such as cavitation\, shock wav es\, and a supersonic splash. I will also briefly describe some new result s from hypersonic free flight experiments using the same facility and high light important associated diagnostic tools. LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/aerospace-colloquium END:VEVENT BEGIN:VEVENT SUMMARY:Susan and James Wu Aerospace Colloquium DTSTART;TZID=America/Los_Angeles:20260508T150000 DTEND;TZID=America/Los_Angeles:20260508T160000 DTSTAMP:20260416T225443Z UID:Susan and James Wu Aerospace Colloquium@Fri May 8 15:00:00 2026@galci t.divisions.caltech.edu CATEGORIES: DESCRIPTION:Christoph Brehm\, Associate Professor\, Aerospace Engineering\ , University of Maryland\n LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/galcit-colloquium-405 END:VEVENT BEGIN:VEVENT SUMMARY:Susan and James Wu Aerospace Colloquium DTSTART;TZID=America/Los_Angeles:20260515T150000 DTEND;TZID=America/Los_Angeles:20260515T160000 DTSTAMP:20260416T225443Z UID:Susan and James Wu Aerospace Colloquium@Fri May 15 15:00:00 2026@galci t.divisions.caltech.edu CATEGORIES: DESCRIPTION:Sean Mendoza\, PhD Candidate\, Aerospace Department\, Californ ia Institute of Technology\n LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/galcit-colloquium-406 END:VEVENT BEGIN:VEVENT SUMMARY:The Kinematics of Life The Evolving Role of Robot Kinematics in Bi o-Nanotechnology DTSTART;TZID=America/Los_Angeles:20260522T150000 DTEND;TZID=America/Los_Angeles:20260522T160000 DTSTAMP:20260416T225443Z UID:Susan and James Wu Aerospace Colloquium@Fri May 22 15:00:00 2026@galci t.divisions.caltech.edu CATEGORIES: DESCRIPTION:Kazem Kazerounian\, Professor\, Mechanical Engineering Departm ent\, University of Conneticut\nThe fusion of kinematics\, and in particul ar robot kinematics\, a field centered on motion and geometry\, with molec ular biology has opened new avenues in disease diagnosis and treatment\, d rug development\, nanomachines\, nano-robots\, nanotechnology\, and sustai nability. In particular\, Proteins are evolution's mechanisms of choice. T he study of nano-mechanical systems must encompass an understanding of the geometry and conformation of protein molecules. Proteins are open or clos ed loop kinematic chains of miniature rigid bodies connected by revolute j oints. The robotics community is in a unique position to extend the bounda ries of knowledge in nano biomechanical systems and bio-nanotechnology. Th is presentation will review the critical role of applied robot kinematics\ , in biotechnology\, particularly in the evolution and discovery of innova tive bio-nanomachines and bio-nano robots over the past 25 years\, leading to establishing the foundation for incorporating kinematic principles in innovative bio-nanomachines. This presentation explores future trends\, an d issues a call to action to the robot kinematics community. Emphasizing t he importance of precise kinematic approaches in understanding protein mol ecules' behavior for nano machine development\, we argue that the robot ki nematics community remains ideally positioned to drive groundbreaking prog ress in bio-nanotechnology and broaden the scope of these approaches in dr ug design\, nanomachines\, and development of new architected materials. LOCATION:Guggenheim 133 (Lees-Kubota Lecture Hall) URL:https://aerospace.caltech.edu/events/seminars/galcit-colloquium-407 END:VEVENT END:VCALENDAR