Mon 17 Feb 13:00: Stratification and mixing regimes in the global coastal ocean: classifications and trends from models and observations
Abstract not available
- Speaker: Jo Hopkins (NOC)
- Monday 17 February 2025, 13:00-14:00
- Venue: MR3, CMS.
- Series: Quantitative Climate and Environmental Science Seminars; organiser: Prof. John R. Taylor.
Fri 14 Feb 16:00: Synchronization in Navier-Stokes turbulence and it's role in data-driven modeling
In Navier-Stokes (NS) turbulence, large-scale turbulent flows determine small-scale flows; in other words, small-scale flows are synchronized to large-scale flows. In 3D turbulence, previous numerical studies suggest that the critical length separating these two scales is determined by the Kolmogorov length. In this talk, I will introduce our theoretical framework for characterizing synchronization phenomena [1]. Specifically, it provides a computational method for the exponential rate of convergence to the synchronized state, and identifies the critical length based on the NS equations via the “transverse” Lyapunov exponent. I will also discuss the synchronization property of 2D NS turbulence and how it differs from the 3D case [2]. These insights into synchronization and critical length scales are essential for developing machine-learning closure models for turbulence, in particular their stable reproducibility [3]. Finally, I will illustrate how “generalized” synchronization is crucial for predicting chaotic dynamics [4].
- Speaker: Professor Masanobu Inubushi, Tokyo University of Science
- Friday 14 February 2025, 16:00-17:00
- Venue: MR2.
- Series: Fluid Mechanics (DAMTP); organiser: Professor Grae Worster.
Fri 07 Mar 16:00: TBA
Abstract not available
- Speaker: Professor Tanniemola Liverpool, University of Bristol
- Friday 07 March 2025, 16:00-17:00
- Venue: MR2.
- Series: Fluid Mechanics (DAMTP); organiser: Professor Grae Worster.
Fri 21 Feb 15:00: Post-doc talks
Abstract not available
- Speaker: Post-doc talks, DAMTP
- Friday 21 February 2025, 15:00-17:00
- Venue: MR2.
- Series: Fluid Mechanics (DAMTP); organiser: Professor Grae Worster.
Fri 14 Mar 16:00: Turbulent zonal jets: self-organization and wave-mean flow interactions
The colourful bands of Jupiter are sustained by intense east-west winds called zonal jets, which extend well below Jupiter’s weather layer into its mantle of liquid hydrogen. These jets constitute a fascinating natural example of how a rapidly-rotating turbulent flow self-organises at large scale. Despite decades of observations and modelling, understanding the long-term, nonlinear equilibration of zonal jets and the feedback with the underlying turbulence and waves is still a challenge. In this seminar, I will discuss the dynamics of zonal jets from a wave-mean flow interaction perspective, using a combination of rapidly-rotating laboratory experiments, numerical models and theoretical analyses. I will highlight the essential role of Rossby waves in the emergence and nonlinear saturation of turbulent jets, as demonstrated experimentally and theoretically with a simple quasi-linear model. Following a similar approach as in the Holton-Lindzen-Plumb model for mean flow reversals in stratified fluids, I will extend this quasi-linear analytical model to study jets’ coarsening, and discuss the final scale and amplitude of zonal winds when they are locally versus globally-driven.
- Speaker: Dr Daphné Lemasquerier, University of St Andrews
- Friday 14 March 2025, 16:00-17:00
- Venue: MR2.
- Series: Fluid Mechanics (DAMTP); organiser: Professor Grae Worster.
Fri 21 Mar 16:00: Nonmonotonic flow curves and shear banding in granular flows
Dense granular packings, both dry and suspended in liquid, are among the most abundant materials on earth. They are relevant to manifold geophysical phenomena, e.g., landslides and debris flows, and to industrial processes such as paste extrusion. Understanding their deformation and flow properties is thus of major practical importance. It is also of fundamental interest in statistical physics, fluid mechanics and rheology. Here we use particle simulations to map comprehensively the shear rheology of dry and wet granular matter comprising particles of finite stiffness, in both fixed pressure and fixed volume protocols. At fixed pressure we find nonmonotonic constitutive curves that are shear thinning, whereas at fixed volume we find nonmonotonic constitutive curves that are shear thickening. We show that the presence of one nonmonotonicity does not imply the other. Instead, there exists a signature in the volume fraction measured under fixed pressure that, when present, ensures nonmonotonic constitutive curves at fixed volume. In the context of dry granular flow we show that gradient and vorticity bands arise under fixed pressure and volume respectively, as implied by the constitutive curves. For wet systems our results are consistent with a recent experimental observation of shear thinning at fixed pressure. Reconciling these rich banding dynamics with a detailed mechanistic description accounting also for non-locality and boundary effects remains an open challenge.
- Speaker: Dr Christopher Ness, University of Edinburgh
- Friday 21 March 2025, 16:00-17:00
- Venue: MR2.
- Series: Fluid Mechanics (DAMTP); organiser: Professor Grae Worster.
From securing pets to building ‘insect hotels’ – here are 7 ways to attract birds to your garden
Mon 17 Feb 13:00: Title to be confirmed
Abstract not available
- Speaker: Jo Hopkins (NOC)
- Monday 17 February 2025, 13:00-14:00
- Venue: MR3, CMS.
- Series: Quantitative Climate and Environmental Science Seminars; organiser: Prof. John R. Taylor.
Fri 31 Jan 16:00: Cracking the capillary code: towards mesoscopic self-assembly and functional micromachines
Self-assembly, a spontaneous process driven by thermal agitation and intermolecular interactions, is crucial for the formation and folding of complex macromolecules, with profound implications for chemistry and biology. While extensively studied at the molecular level, capillary-driven self-assembly has emerged as a promising approach for constructing structures at the mesoscopic scale, bridging the gap between classical bottom-up and top-down fabrication methods. Operating between 10 micrometers to 10 millimeters, this approach has, over two decades, largely produced regular or simplistic structures. This work leverages experimental and statistical physics to unveil methodologies for controlling subtle capillary interactions, enabling the design of intricate and highly complex structures. We demonstrate how these mesoscopic systems act as analogs for molecular phenomena, such as folding, lock-and-key mechanisms, and crystallization processes. Furthermore, by incorporating magnetic actuation, we explore the dynamic self-assembly of functional micromachines. These micromachines present potential applications in interface cleaning, particle sorting, and targeted transport, underscoring the transformative possibilities of capillary-driven systems for soft robotics and materials science.
- Speaker: Professor Nicolas Vandewalle, University of Liège
- Friday 31 January 2025, 16:00-17:00
- Venue: MR2.
- Series: Fluid Mechanics (DAMTP); organiser: Professor Grae Worster.
Fri 28 Feb 16:00: Fast flow of an Oldroyd-B fluid through a slowly varying contraction
Lubrication theory is adapted to incorporate the large normal stresses that occur for order-one Deborah numbers, $De$, the ratio of the relaxation time to the residence time.
Comparing with the pressure drop for a Newtonian viscous fluid with a viscosity equal to that of an Oldroyd-B fluid in steady simple shear, we find numerically a reduced pressure drop through a contraction and an increased pressure drop through an expansion, both changing linearly with $De$ at high $De$. For a constriction there is a smaller pressure drop that plateaus at high $De$. Much of the change in pressure drop occurs in the stress relaxation in a long exit channel.
An asymptotic analysis for high $De$, based on the idea that normal stresses are stretched by an accelerating flow in proportion to the square of the velocity, reveals that the large linear changes in pressure drop are due to higher normal stresses pulling the fluid through the narrowest gap. A secondary cause of the reduction is that the elastic shear stresses do not have time to build up to their steady state equilibrium value while they accelerate through a contraction.
And experiments find differently!
- Speaker: Professor John Hinch, DAMTP
- Friday 28 February 2025, 16:00-17:00
- Venue: MR2.
- Series: Fluid Mechanics (DAMTP); organiser: Professor Grae Worster.
Fri 14 Feb 17:30: Epigenetics: A Code upon a Code?
Biography
Professor Anne Ferguson-Smith is the Executive Chair of the Biotechnology and Biological Sciences Research Council (BBSRC). Before this appointment she served as Pro-Vice-Chancellor (Research and International Partnerships) at the University of Cambridge. A renowned mammalian developmental geneticist, genome biologist and epigeneticist, Professor Ferguson-Smith is the Balfour Professor of Genetics in the University of Cambridge’s Department of Genetics where she served as Head of Department from 2013-2020. She is also a Fellow of Darwin College.
At the University of Cambridge, Professor Ferguson-Smith leads a research group comprised of experimental and computational scientists. They focus on the epigenetic control of genome function, particularly on models of epigenetic inheritance with implications for health and disease. Committed to the training and professional development of new talent, her team’s current work includes investigating how genetic, epigenetic and environmental factors influence cellular and developmental processes.
In 2017, Anne was elected a Fellow of the Royal Society and in 2021 received their Buchanan Medal for her pioneering work on epigenetics. In 2023, she was named Commander of the British Empire (CBE) for her research contributions.
Photo – Dasha Tenditna
- Speaker: Professor Anne Ferguson-Smith, University of Cambridge
- Friday 14 February 2025, 17:30-18:30
- Venue: Lady Mitchell Hall, Sidgwick Avenue.
- Series: Darwin College Lecture Series; organiser: Janet Gibson.
Fri 14 Feb 17:30: Epigenetics: A Code upon a Code?
Biography
Professor Anne Ferguson-Smith is the Executive Chair of the Biotechnology and Biological Sciences Research Council (BBSRC). Before this appointment she served as Pro-Vice-Chancellor (Research and International Partnerships) at the University of Cambridge. A renowned mammalian developmental geneticist, genome biologist and epigeneticist, Professor Ferguson-Smith is the Balfour Professor of Genetics in the University of Cambridge’s Department of Genetics where she served as Head of Department from 2013-2020. She is also a Fellow of Darwin College.
At the University of Cambridge, Professor Ferguson-Smith leads a research group comprised of experimental and computational scientists. They focus on the epigenetic control of genome function, particularly on models of epigenetic inheritance with implications for health and disease. Committed to the training and professional development of new talent, her team’s current work includes investigating how genetic, epigenetic and environmental factors influence cellular and developmental processes.
In 2017, Anne was elected a Fellow of the Royal Society and in 2021 received their Buchanan Medal for her pioneering work on epigenetics. In 2023, she was named Commander of the British Empire (CBE) for her research contributions.
Photo – Dasha Tenditna
- Speaker: Professor Anne Ferguson-Smith, University of Cambridge
- Friday 14 February 2025, 17:30-18:30
- Venue: Lady Mitchell Hall, Sidgwick Avenue.
- Series: Darwin College Lecture Series; organiser: Janet Gibson.
Fri 14 Feb 17:30: Epigenetics: A Code upon a Code?
Biography
Professor Anne Ferguson-Smith is the Executive Chair of the Biotechnology and Biological Sciences Research Council (BBSRC). Before this appointment she served as Pro-Vice-Chancellor (Research and International Partnerships) at the University of Cambridge. A renowned mammalian developmental geneticist, genome biologist and epigeneticist, Professor Ferguson-Smith is the Balfour Professor of Genetics in the University of Cambridge’s Department of Genetics where she served as Head of Department from 2013-2020. She is also a Fellow of Darwin College.
At the University of Cambridge, Professor Ferguson-Smith leads a research group comprised of experimental and computational scientists. They focus on the epigenetic control of genome function, particularly on models of epigenetic inheritance with implications for health and disease. Committed to the training and professional development of new talent, her team’s current work includes investigating how genetic, epigenetic and environmental factors influence cellular and developmental processes.
In 2017, Anne was elected a Fellow of the Royal Society and in 2021 received their Buchanan Medal for her pioneering work on epigenetics. In 2023, she was named Commander of the British Empire (CBE) for her research contributions.
Photo – Dasha Tenditna
- Speaker: Professor Anne Ferguson-Smith, University of Cambridge
- Friday 14 February 2025, 17:30-18:30
- Venue: Lady Mitchell Hall, Sidgwick Avenue.
- Series: Darwin College Lecture Series; organiser: Janet Gibson.
Fri 07 Feb 16:00: Bubble dynamics in complex fluids
Bubble dynamics and cavitation have traditionally been studied in the context of underwater acoustics and, more recently, biomedical applications. I will discuss how the deformation and flow fields generated by acoustically-driven bubbles can be used to drive self-assembly of novel microstructures in complex fluids. Bubble dynamics driven at ultrasonic frequencies probe time scales as short as 10ˉ³−10ˉ⁶ s, comparable to the smallest relaxation time scales for complex fluids containing suspended particles or macromolecules. I will describe how, in this dynamical regime, dynamic capillary interactions arise between colloidal particles adsorbed at a fluid interface, producing particle networks that dominate the mechanics of these complex interfaces under flow. I will also describe a new flow-induced mechanism caused by bubble dynamics, that produces ordered microstructures in colloidal gels. This mechanism can enable energy-efficient processing methods of colloidal-gel materials, including inks, battery electrodes, construction materials. I will also discuss the emerging approach of using bubble dynamics to probe the high-frequency viscoelastic properties of complex fluids and soft materials, which has brought together the communities of cavitation and rheology to address new challenges in characterization of soft materials.
Cassyni Link below:
https://cassyni.com/events/AyG2QQDJ3FQqksbaTP2zAh
- Speaker: Professor Valeria Garbin, Delft University of Technology
- Friday 07 February 2025, 16:00-17:00
- Venue: Fluid Mechanics Webinar Series.
- Series: Fluid Mechanics (DAMTP); organiser: Professor Grae Worster.
Mon 17 Mar 13:00: Title to be confirmed
Abstract not available
- Speaker: Jesse Taylor-West (Bath)
- Monday 17 March 2025, 13:00-14:00
- Venue: MR3, CMS.
- Series: Quantitative Climate and Environmental Science Seminars; organiser: Dr Kasia Warburton.
Mon 10 Mar 13:00: Title to be confirmed
Abstract not available
- Speaker: Becky Dell (Geography)
- Monday 10 March 2025, 13:00-14:00
- Venue: MR3, CMS.
- Series: Quantitative Climate and Environmental Science Seminars; organiser: Dr Kasia Warburton.
Mon 03 Mar 13:00: Title to be confirmed
Abstract not available
- Speaker: Rob Hall (UEA)
- Monday 03 March 2025, 13:00-14:00
- Venue: MR3, CMS.
- Series: Quantitative Climate and Environmental Science Seminars; organiser: Bethan Wynne-Cattanach.
Mon 24 Feb 13:00: Title to be confirmed
Abstract not available
- Speaker: Helen Roberts (Met Office)
- Monday 24 February 2025, 13:00-14:00
- Venue: MR3, CMS.
- Series: Quantitative Climate and Environmental Science Seminars; organiser: Bethan Wynne-Cattanach.
Mon 10 Feb 13:00: Title to be confirmed
Abstract not available
- Speaker: Adrien Lefauve (DAMTP, University of Cambridge)
- Monday 10 February 2025, 13:00-14:00
- Venue: MR3, CMS.
- Series: Quantitative Climate and Environmental Science Seminars; organiser: Dr Kasia Warburton.
Mon 03 Feb 13:00: Title to be confirmed
Abstract not available
- Speaker: Will Seviour (Exeter)
- Monday 03 February 2025, 13:00-14:00
- Venue: MR3, CMS.
- Series: Quantitative Climate and Environmental Science Seminars; organiser: Bethan Wynne-Cattanach.