Applied Mathematics Seminars Autumn 2008

All seminars (unless otherwise stated) will take place on Mondays at 3.00 pm in Room 500 which is located on the 5th floor of the Mathematics Department. See Where to Find Us for further details. There will be tea afterwards in room 606.

If you require any more information on the Applied seminars please contact Professor Yaroslav Kurylev e-mail: y.kurylev AT ucl.ac.uk or tel: 020-7679-7896.

13 October 2008

Professor John Maddocks- Swiss Federal Institute of Technology

Stokes Flows, Rigid Bodies, and Ideal Knot Shapes

10 November 2008

Professor N. Sandham - University of Southampton 

Transitional Separation Bubbles and Unsteady Aspects of Aerofoil Stall


Recent interest in aerofoil design for low speed applications (e.g. micro and small unmanned air vehicles) has led to renewed interest in laminar separation bubbles. This talk will review results from recent direct numerical simulations of flow over a NACA 0012 aerofoil section at a Reynolds number of 50,000. The laminar separation bubble on the aerofoil is observed to undergo a self-sustained transition to turbulence i.e. transition that persists even in the absence of upstream disturbances. The addition of forcing is found to decrease the bubble length and reduce the drag coefficient by 18%. Based on the simulation results, an unsteady viscous-inviscid interaction method, coupling integral boundary-layer methods with a potential flow solution based on panel methods, is developed to study separation bubble behaviour near stall. The method is capable of predicting large-amplitude low-Strouhal number oscillations as seen in recent experiments. Above a critical incidence the reattachment point can no longer be held and the flow develops a limit cycle behaviour in which bubble growth leads to fully stalled flow followed by a reformation of the bubble.

17 November 2008

Dr I Marshall - Loughborough University 

Hidden Poisson structures in the Schrodinger equation

24 November 2008

Professor Y. Shikhmurzaev - University of Birmingham

Capillary flows with forming interfaces


A variety of free-surface flows will be considered where the "golden standard" of fluid mechanics, i.e. the Navier-Stokes equations together with classical boundary conditions, manifestly fails to produce physically meaningful results (and sometimes any results). We will show that paradoxes inherent in the mathematical modelling of seemingly very different flows come from a common root: the fact that the "golden standard" presumes that the interfaces, where boundary conditions for the Navier-Stokes equations have to be formulated, have already formed, whereas in the flows in question it is the process of interface formation that determines key features of the flow. The simplest mathematical model addressing the issue will be outlined. Some unresolved problems in the area of capillary flows will also be discussed.

01 December 2008

Professor A. S. Fokas - University of Cambridge 

Generalized Forier Transform, Inverse Problems and Integrability in 4+2


Three different types of generalized Fourier transforms will be discussed, which appear in the following: (a) The medical imaging technique called Single Photon Emission Computerized Tomography (SPECT). (b) The solution of the Cauchy problem of integrable nonlinear evolution PDEs in 4+2, i.e. in four spatial and two temporal dimensions. (c) The characterization of the generalized Dirichlet to Neumann map for integrable nonlinear evolution PDEs in 1+1, i.e. in one spatial and one temporal dimensions.

08 December 2008

Professor L. Harra - UCL 

The impact of the Sun on the Earth - a view from the Hinode space mission


The Japanese/US/UK Hinode space mission was launched in September 2006. Its purpose is to explore and quantify solar activity that impacts us on Earth. This includes understanding the source of the solar wind that is transported throughout the solar system and the trigger of large explosions on the Sun (known as solar flares) and associated coronal mass ejections.