Fri, 21 Nov 2014

10:00 - 11:00
L5

Workshop with Sharp - Two Modelling Problems: (i) Freezing Particle-Containing Liquids and (ii)Llithium/Sodium Batteries

Abstract

Abstract:

(i) We consider the modelling of freezing of fluids which contain particulates and fibres (imagine orange juice “with bits”) flowing in channels. The objective is to design optimum geometry/temperatures to accelerate freezing.

(ii) We present the challenge of setting-up a model for lithium or sodium ion stationary energy storage cells and battery packs to calculate the gravimetric and volumetric energy density of the cells and cost. Depending upon the materials, electrode content, porosity, packing electrolyte and current collectors. There is a model existing for automotive called Batpac.

Oxygen has a significant prognostic effect on cancer treatment, with well-oxygenated regions being more sensitive to radiotherapy than low oxygen regions. Better understanding of oxygen distribution could allow escalation of dose to hypoxic regions and better prognosis.

Thu, 19 Feb 2015

16:00 - 17:00
L3

Nonlinear Dynamics in Phononic Lattices

Chris Chong
(ETHZ)
Abstract
This talk concerns the behavior of acoustic waves within various nonlinear materials.  As a prototypical example we consider a system of discrete particles that interact nonlinearly through a so-called Hertzian contact.  With the use of analytical, numerical and experimental approaches we study the formation of solitary waves, dispersive shocks, and discrete breathers.
 
Thu, 12 Feb 2015

16:00 - 17:00
L3

Convection of a reactive solute in a porous medium

Oliver Jensen
(Manchester)
Abstract

Abstract: Motivated loosely by the problem of carbon sequestration in underground aquifers, I will describe computations and analysis of one-sided two-dimensional convection of a solute in a fluid-saturated porous medium, focusing on the case in which the solute decays via a chemical reaction.   Scaling properties of the flow at high Rayleigh number are established and rationalized through an asymptotic model, that addresses the transient stability of a near-surface boundary layer and the structure of slender plumes that form beneath.  The boundary layer is shown to restrict the rate of solute transport to deep domains.  Knowledge of the plume structure enables slow erosion of the substrate of the reaction to be described in terms of a simplified free boundary problem.

Co-authors: KA Cliffe, H Power, DS Riley, TJ Ward

 

Thu, 22 Jan 2015

16:00 - 17:00
L3

Fingers and Flowers: Flow, transport, and deformation in porous materials

Chris MacMinn
(Oxford Engineering)
Abstract
Coupling across scales is often particularly strong in porous rocks,
soils, and sediments, where small-scale physical mechanisms such as
capillarity, erosion, and reaction can play an important role in
phenomena at much larger scales. Here, I will present two striking
examples of this coupling: (1) carbon sequestration, where storage
security relies on the action of millimeter-scale trapping mechanisms
to immobilise kilometer-scale plumes of buoyant carbon dioxide in the
subsurface, and (2) fluid injection into a granular solid, where
macroscopic poromechanics drive grain-scale deformation and failure.
I will show how we derive physical insight into the behaviour of these
complex systems with an effective combination of theoretical models,
numerical simulations, and laboratory experiments.

Jackie Stedall came to Oxford in October 2000 as Clifford-Norton Student in the History of Science at Queen’s College. She held degrees of BA (later MA) in Mathematics from Cambridge University (1972), MSc in Statistics from the University of Kent (1973), and PhD in History of Mathematics from the Open University (2000). She also had a PGCE in Mathematics (Bristol Polytechnic 1991).

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