Geometry optimisation of wave energy converters
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Abstract
Wave energy has the theoretical potential to meet global electricity demand, but it remains less mature and less cost-competitive than wind or solar power. A key barrier is the absence of engineering convergence on an optimal wave energy converter (WEC) design. In this work, I demonstrate how geometry optimisation can deliver step-change improvements in WEC performance. I present methodology and results from optimisations of two types of WECs: an axisymmetric point-absorber WEC and a top-hinged WEC. I show how the two types need different optimisation frameworks due to the differing physics of how they make waves. For axisymmetric WECs, optimisation achieves a 69% reduction in surface area (a cost proxy) while preserving power capture and motion constraints. For top-hinged WECs, optimisation reduces the reaction moment (another cost proxy) by 35% with only a 12% decrease in power. These result show that geometry optimisation can substantially improve performance and reduce costs of WECs.
15:00
Integrating lab experiments into fluid dynamics models
Abstract
In this talk, we will explore three flow configurations that illustrate the behaviour of slow-moving viscous fluids in confined geometries: viscous gravity currents, fracturing of shear-thinning fluids in a Hele-Shaw cell, and rectangular channel flows of non-Newtonian fluids. We will first develop simple mathematical models to describe each setup, and then we will compare the theoretical predictions from these models with laboratory experiments. As is often the case, we will see that even models that are grounded in solid physical principles often fail to accurately predict the real-world flow behaviour. Our aim is to identify the primary physical mechanisms absent from the model using laboratory experiments. We will then refine the mathematical models and see whether better agreement between theory and experiment can be achieved.
Tsunamis; and how to protect against them
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Professor Herbert Eric Huppert FRS
University of Cambridge | University of New South Wales
Herbert Huppert (b. 1943, Sydney) is a British geophysicist renowned for his pioneering work applying fluid mechanics to the Earth sciences, with contributions spanning meteorology, oceanography, and geology. He has been Professor of Theoretical Geophysics and the Founding Director of the Institute of Theoretical Geophysics at the University of Cambridge since 1989, and a Fellow of King’s College, Cambridge, since 1970. He has held a part-time Professorship at the University of New South Wales since 1990.
Elected a Fellow of the Royal Society in 1987, Huppert has served on its Council and chaired influential working groups on bioterrorism and carbon capture and storage. His distinctions include the Arthur L. Day Prize and Lectureship from the US National Academy of Sciences (2005), the Bakerian Lecture (2011), and a Royal Medal (2020). He is also a Fellow of the American Geophysical Union, the American Physical Society, and the Academia Europaea.
Growth, tissue regeneration and active process
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Professor Martine Ben Amar is a theoretical physicist whose work explores the physics and mechanics of soft matter, with applications ranging from fundamental instabilities in solids and fluids to biological growth processes. Her research has addressed phenomena such as dendritic growth, Saffman–Taylor instability, elastic singularities, and morphogenesis in vegetal and animal tissues. More recently, she has focused on the interface between physics and biology, modelling the growth of cancerous tumours through reaction–diffusion equations and studying the role of mechanical stresses in tissue development—work that connects directly with medical applications in collaboration with clinicians.
A graduate in atomic physics, she has taught at UPMC since 1993 and was elected a senior member of the Institut Universitaire de France in 2011. She held the McCarthy Chair at MIT in 1999–2000 and has led the federation Dynamics of Complex Systems, uniting over 200 researchers across Paris institutions. Passionate about science, she describes her vocation as “understanding, showing, and predicting the laws of the universe and life.”
Abstract
When a specimen of non-trivial shape undergoes deformation under a dead load or during an active process, finite element simulations are the only technique for evaluating the deformation. Classical books describe complicated techniques for evaluating stresses and strains in semi-infinite, circular or cylindrical objects. However, the results obtained are limited, and it is well known that elasticity (linear or nonlinear) is strongly intertwined with geometry. For the simplest geometries, it is possible to determine the exact deformation, essentially for low loading values, and prove that there is a threshold above which the specimen loses stability. The next step is to apply perturbation techniques (linear and nonlinear bifurcation theory).
In this talk, I will demonstrate how many aspects can be simplified or revealed through the use of complex analysis and conformal mapping techniques for shapes, strains, and active stresses in thin samples. Examples include leaves and embryonic jellyfish.
Integrating lab experiments into fluid dynamics models
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Ashleigh Hutchinson is an applied mathematician with a strong research focus on fluid mechanics problems rooted in nature and industry. Her work centres on low-Reynolds number flows and non-Newtonian fluids, where she adopts a multidisciplinary approach that combines theoretical models, laboratory experiments, and numerical simulations.
Her other research interests include applying mathematical modelling to solve problems in industries such as finance, sugar, fishing, mining, and energy conservation.
Abstract
In this talk, we will explore three flow configurations that illustrate the behaviour of slow-moving viscous fluids in confined geometries: viscous gravity currents, fracturing of shear-thinning fluids in a Hele-Shaw cell, and rectangular channel flows of non-Newtonian fluids. We will first develop simple mathematical models to describe each setup, and then we will compare the theoretical predictions from these models with laboratory experiments. As is often the case, we will see that even models that are grounded in solid physical principles often fail to accurately predict the real-world flow behaviour. Our aim is to identify the primary physical mechanisms absent from the model using laboratory experiments. We will then refine the mathematical models and see whether better agreement between theory and experiment can be achieved.
Master Stability for Traveling Waves on Networks
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Stefan Ruschel’s research focuses on dynamical systems theory and its applications to nonlinear optics and mathematical biology, among others. He specialises in analytical and numerical methods for delay differential and functional differential equations when the delay is large compared to other time scales of the system. His specific contributions include work on the fixed point spectrum for large delay, as well as the characterisation of slowly oscillating solutions such as travelling pulses and waves.
His future research is dedicated to applying these techniques to delay and lattice dynamical systems arising from coupled excitable and coupled bi-stable systems in laser dynamics and neuroscience, where such solutions play an important role in data transmission and neural signal propagation.
He is currently a research fellow at the University of Leeds (UK), funded by UKRI in recognition of a Horizon Europe MSCA award post-Brexit.
Abstract
I will present a new framework for determining effectively the spectrum and stability of traveling waves on
networks with symmetries, such as rings and lattices, by computing master stability curves (MSCs). Unlike
traditional methods, MSCs are independent of system size and can be readily used to assess wave
destabilization and multi-stability in small and large networks.