Computational Modelling Group

A Fast Multipole Method for the Bessel potential

Marc Molinari, Simon Cox (Investigators), Neil O'Brien

The fast multipole method (FMM) proposed by Greengard and Rokhlin provides a method by which the O(N-squared) many-body problem can be reduced to O(N) complexity. In this project, a multipole method is developed to calculate the energy of a system of vortices in a high temperature superconductor, where the many-body interactions give rise to rich and complex physics. The method developed here is suitable for systems where the interactions are governed by a Bessel potential rather than the usual logarithmic potentials occurring in gravitational and electrostatic problems. We derive and apply vectorised forms of the Gegenbauer addition formulae in order to achieve the O(N) scaling associated with fast multipole methods.

A novel approach to analysing fixed points in complex systems

James Dyke (Investigator), Iain Weaver

This work aims to contribute to our understanding of the relationship between complexity and stability. By describing an abstract coupled life-environment model, we are able to employ novel analytical, and computational techniques to shed light on the properties of such a system.

Assessment of the performance of novel RANS and hybrid turbulence models on the flow around a cylinder

Manuel Diaz Brito

The turbulent flow around a circular cylinder is a widely studied problem in fluid dynamics. At a certain characteristic Reynolds numbers the development of a turbulent wake occurs simultaneously with separation of the laminar boundary layer. The mechanisms defining this critical flow state are very complex to predict computationally. In this project the suitability of novel non-linear eddy viscosity closures and a hybrid Flow Simulation Methodology formulation to face these massively separated flows is studied. The flow predicting capabilities of the baseline EASM, ?-?-EASM and FSM-?-?-EASM tested are contrasted with the industrial renowned k-?-SST turbulence model. In the visualisation of the results it is evident that the ?-?-EASM has greater flexibility estimating the components of the Reynolds stresses with respect to the baseline EASM and the k-?-SST. Although dome differences are observed, the prediction of the critical flow around a cylinder is not accurately achieved by any of these RANS models, but the FSM-?-?-EASM shows great resemblance with the validation data, demonstrating capabilities of resolving very complex flow phenomena with minimum user input if the computational grid is fine enough. In order to demonstrate even greater advantages of non-linear models it was postulated that the addition of a streamwise impinging vortex hitting the leading edge of the cylinder would make the flow field fully three-dimensional. First attempts were tried in this route but time constraints limited the ultimate scope of the present work.

BRECcIA - Building REsearch Capacity for sustainable water and food security In sub-saharan Africa

The BRECcIA project is aimed at developing research and researchers to understand water and food security challenges in sub-Saharan Africa

Cavity-Mediated Cooling

Peter Horak, Timothy Freegarde (Investigators), Andre Xuereb

Optical resonators enhance the interaction of light with matter while simultaneously acting as a temporal buffer. Both effects can be exploited to generate light-induced friction, or cooling, forces on atoms, molecules, or micromirrors. We investigate various aspects of these effects through numerical simulations, assisted by approximate analytical models, in this EPSRC and ESF sponsored project.

Cellular Automata Modelling of Membrane Formation and Protocell Evolution

Seth Bullock (Investigator), Stuart Bartlett

We simulated the meso-level behaviour of lipid-like particles in a range of chemical and physical environments. Self-organised protocellular structures can be shown to emerge spontaneously in systems with random, homogeneous initial conditions. Introducing an additional 'toxic' particle species and an associated set of synthesis reactions produced a new set of ecological behaviours compared to the original model of Ono and Ikegami.

Chaotic Analysis of Partial Discharge

Paul Lewin (Investigator), Lyuboslav Petrov

The deterministic character of PD pulses predicted by theory has been shown to be existent for certain PD events. Finding characteristic patterns in phase space enables field-data PD detection with high reliability.

Chip Implementation of a Signal Detector for a Multiple-Input Multiple-Output (MIMO) Wireless System

Mark Zwolinski, Basel Halak, Mohammed El-Hajjar (Investigators), Ibrahim Bello

We implement an Application Specific Integrated Circuit (ASIC) for the signal detection of a MIMO receiver.

Computational electromagnetic modelling of 3D photonic structures

Marc Molinari, Darren Bagnall, Simon Cox (Investigators), Asa Asadollahbaik, Elizabeth Hart

Nano-structured materials can provide very specific and often very special optical effects which can be exploited for a large range of optical applications including wavelength filters, LEDs, micro-lasers, HDTV, solar-cell coatings, optical high-Q fibres, diffraction gratings, polarisation devices, optical switches, etc. This research in “Computational Electromagnetic Modelling of 3D Photonic Structures” aims to address the need for accurate and fast three-dimensional modelling, simulation and analysis processes in the photonics industry. A FEM/FDTD software suite will be developed to simulate Maxwell’s field equations and thin-film quantum effects (plasmons) in the visible and near-infrared EM frequency spectrum. The results obtained from running the software on suitable compute clusters will then be compared to the analysis results of experimentally manufactured materials. We will investigate structures occurring in nature such as iridescent butterfly wings, white/black reflecting beetle shells, etc., and aim to optimise artificially designed structures with periodic, quasi-periodic and random configurations.

Computational Methods for Aircraft Noise Prediction

Gwenael Gabard (Investigator), Albert Prinn

The aim of this project is to develop and test an efficient flow acoustics solver based on the finite element method and the potential flow theory.

Continuously Tunable Optical Buffer

Peter Horak (Investigator)

The project aims to design, fabricate and test a novel integrated all-optical buffer device that is based on MEMS technology and provides a continuously tunable delay for optical pulses over a broad wavelength region. Such a device could play a crucial role in future packet-switched optical networks, photonic integrated circuits and coherent light based applications such as optically steered phase array antennas, LIDAR and optical coherence tomography.

This EPSRC funded project is a collaboration between the Optoelectronics Research Centre, Southampton, and University College London.

Coupled Fluid-Structure Interaction to model Three-Dimensional Dynamic Behaviour of Ships in Waves

Pandeli Temarel, Zhi-Min Chen (Investigators), Puram Lakshmynarayanana

In the present study we focus our attention on fluid-structure interactions (FSI) of flexible marine structures in waves by coupling a fluid solver using Computational Fluid Dynamics (CFD) and a structural solver using Finite Element Analysis (FEA) software.

DePuy Technology Partnership

Mark Taylor (Investigator), Adam Briscoe

This initiative concerns the transfer of knowledge between three key institutions (University of Southampton, University of Leeds and University of Hamburg) and DePuy International limited. The project is concerned with the ongoing advancement of technology used in orthopaedic devices.

Desiging Near-Capacity Quantum Error Correction Codes

Lajos Hanzo (Investigator), Zunaira Babar

Design efficient quantum error correction codes to correct the errors encountered in a quantum transmission; thus, increasing reliability and robustness of the future quantum systems.

Design of Unmanned Air Vehicles

James Scanlan (Investigator), Robert Entwistle

Using computational modelling of a 3D airspace simulation environment to meet the safety and collision-avoidance requirements of the certification authorities.

Discrete ECogeomorphic Aeolian Landscape (DECAL) modelling

Joanna Nield (Investigator)

DECAL is a cellular automaton based model which incorporated mutual feedback processes between geomorphic forcing and ecological growth to investigate fundamental controls, self-organising and non-linear behaviour in semi-arid aeolian dune environments. This project explores landscape evolution and disturbance response, developing a phase-space in which dune fields can be quantified.

Efficient algorithms for liquid crystal alignment

Giampaolo D'Alessandro, Timothy Sluckin (Investigators)

We have developed an efficient algorithm to determine the liquid crystal alignment in the absence of defects. The aim of this project is to extend this algorithm to include defects.

EuroSat4PhenoChanges. Using MERIS for monitoring phenology in Europe.

Peter Atkinson (Investigator), Victor Rodriguez Galiano

Monitoring vegetation phenology at multiple scales in Europe from the GMES satellite sensor time-series: a special consideration to natura2000 areas

Fidelity optimisation in an atomic quantum computer

Timothy Freegarde (Investigator), Jack Saywell

Development of optimised composite pulses for atomic quantum computers with the aim of reducing systematic errors in information processing caused by variations in laser intensity and environment.

Fluid Loads and Motions of Damaged Ships

Dominic Hudson, Ming-yi Tan (Investigators), Christian Wood, James Underwood, Adam Sobey

An area of research currently of interest in the marine industry is the effect of damage on ship structures. Research into the behaviour of damaged ships began in the mid nineties as a result of Ro-Ro disasters (e.g. Estonia in 1994). Due to the way the Estonia sank early research mainly focused on transient behaviour immediately after the damage takes place, the prediction of capsize, and of large lateral motions. Further research efforts, headed by the UK MoD, began following an incident where HMS Nottingham ran aground tearing a 50m hole from bow to bridge, flooding five compartments and almost causing the ship to sink just off Lord Howe Island in 2002. This project intends to answer the following questions:
“For a given amount of underwater damage (e.g. collision or torpedo/mine hit), what will be the progressive damage spread if the ship travels at ‘x’ knots? OR for a given amount of underwater damage, what is the maximum speed at which the ship can travel without causing additional damage?”

Generating Optimal Ensembles of Earth System Models

Simon Cox (Investigator), Elizabeth Hart, Andras Sobester

GENIE is an Earth system model of intermediate complexity. As with other climate models, the tuning of its parameters is essential for providing reliable long-term forecasts of Earth system behaviour. We apply a multi-objective optimization algorithm to the problem. The aim of the tuning exercise is to find the optimal values for the free parameters that produce and euqilibrium model end state with the closest fit to equivalent observational data.

Gravitational waves from neutron stars

Ian Hawke (Investigator)

Gravitational waves, once detected, will give information about the extremes of space and time. Compact objects such as neutron stars are perfect locations for generating such waves.

Hadronic structure on the computer

Jonathan Flynn (Investigator), Dirk Broemmel, Thomas Rae, Ben Samways

In experiments at the Large Hadron Collider (LHC) at CERN, Geneva, the interactions that occur between the colliding particles (protons in this case) can be factorised into a simple scattering between two constituent particles, called quarks, followed by a hadronisation process, which describes the dynamics of forming the bound proton states. Quarks are particles within the proton that bind to form composite particles (hadrons) such as a proton. The scattering process can be computed relatively easily, but hadronisation is intrinsically non-perturbative and hard to calculate. Lattice QCD (computer simulation of QCD on a discrete space-time lattice) provides our only known first-principles and systematically-improvable method to address problems like hadronisation. This project uses Iridis to extract parton distribution amplitudes which are experimentally inaccessible, but needed to describe the quark structure of hadrons.

Homogenisation of liquid crystal colloids

Giampaolo D'Alessandro, Keith Daly (Investigators), Thomas Bennett

We use homogenization thoery to obtain macroscopic governing equations for nematic liquid crystals that host arbitrarily shaped nano particles.

Image Based Modelling of Fluid Flow through Lymph Nodes

Tiina Roose, Bharathram Ganapathisubramani, Geraldine Clough (Investigators), Laura Cooper

In this project we are using images of mouse lymph nodes to investigate the fluid transport pathways through it. The images of the nodes are taken using selective plane illumination microscopy, and synchrotron micro computed tomography. The fluid flow is modelled using Darcy's law in COMSOL Multiphysics and the models are run on the Iridis cluster.

Immunotherapy Research: Modelling MHC Class I Complex Assembly

Timothy Elliott, Jorn Werner (Investigators), Alistair Bailey

This project uses mathematical modelling and simulation to investigate mechanisms by which our cells process and present biological information that is used by our immune system to distinguish between healthy and diseased cells.

Investigation of acoustic radiation forces on micro-particles and cells in ultrasonic particle manipulation

Martyn Hill (Investigator), Puja Mishra

A Finite Element model is developed to investigate the force generated on a particle of arbitrary geometry and composition in a sound field. The model overcame the drawbacks of existing analytical solutions of size restriction and provided the flexibility of particle representation. This suggested useful results on shape dependency, effect of elasticity of particle and dominancy of nucleus in a cell in estimating the force on a single particle.

Investigations of Lymphatic Fluid Flow

Tiina Roose, Bharathram Ganapathisubramani, Geraldine Clough (Investigators), Laura Cooper

The lymphatic system performs three main roles returns interstitial fluid back into the blood stream to maintain tissue fluid homeostasis. The aim of this project is to increase our understanding of how the lymph flows through the system by creating three dimensional fluid structure interaction models of the secondary lymphatic valves and image based models of lymph nodes.

Life assessment methods for industrial steam turbine blade to disc interfaces

Katherine Soady (Investigator)

This is an EngD project sponsored by E.ON New Build and Technology Ltd. which aims to develop the methods currently implemented in life assessment of industrial steam turbine blade to disc interfaces to take account of the surface treatment process (shot peening) which is applied to component before service and after repair.

Mathematical modelling of plant nutrient uptake

Tiina Roose (Investigator)

In this project I will describe a model of plant water and nutrient uptake and how to translate this model and experimental data from the single root scale to the root branching structure scale.

Mathematical tools for analysis of genome function, linkage disequilibrium structure and disease gene prediction

Mahesan Niranjan, Andrew Collins, Reuben Pengelly (Investigators)

This iPhD project uses a Gaussian Bayesian Networks framework through Machine learning methods to predict which genes are involved in the development of different diseases.

Measuring biomolecules - improvements to the spectroscopic ruler

Pavlos Lagoudakis, Tom Brown (Investigators), Jan Junis Rindermann, James Richardson

The spectroscopic ruler is a technique to measure the geometry of biomolecules on the nm scale by labeling them with pairs of fluorescent markers and measuring distance dependent non-radiative energy transfer between them. The remaining uncertainty in the application of the technique originates from the unknown orientation between the optical dipole moments of the fluorescent markers, especially when the molecule undergoes thermal fluctuations in physiological conditions. Recently we introduced a simulation based method for the interpretation of the fluorescence decay dynamics of the markers that allows us to retrieve both the average orientation and the extent of directional fluctuations of the involved dipole moments.

Meshless Methods for Photonic Crystal Modelling

Kamal Djidjeli, Marc Molinari, Simon Cox (Investigators), Neil O'Brien, Elizabeth Hart

We apply meshless methods to the problems of simulating photonic crystals. The meshless methods utilise compactly-supported radial basis functions (CSRBFs) and offer a promising alternative to the conventional plane-wave expansion method for calculating the band structure of photonic crystals.

Modelling mechanoreceptor reaction to tissue deformation

Mark Taylor (Investigator), Gwen Palmer

This project involved the modelling of a piece of knee joint capsule, which will produce an electrical output when mechanically stimulated. The model is based on expermental work carried out by P. Grigg and A.H. Hoffman (1982).

Modelling neuronal activity at the knee joint

Mark Taylor, Tiina Roose (Investigators), Gwen Palmer

The function of the knee joint is reliant on proprioception, which involves the response of nerve endings in the tissues at the joint. This project will be concentrating on the neuronal activity, caused by mechanical stimuli, of the more common receptors found at the knee (Ruffini, Paciniform, Golgi and Nociceptor).

There are three stages to this project:
1. Modelling the behaviour of each individual receptor, with the use of the Hodgkin-Huxley model [1].
2. These models will then be applied to the soft tissues around a knee, where a global deformation of the tissue will result in local stimulation of receptors.
3. The soft tissue models will then be applied to structures in the knee.

[1] - Hodgkin, A.L. and A.F. Huxley, A quantitative description of membrane current and its application to conduction and excitation in nerve. Journal of Physiology, 1952. 117: p. 500-544.

Modelling the Combined Effects of Total Ionizing Dose and Random Dopant Fluctuations in sub-100 nm gate-length Transistors

Kees de Groot (Investigator), Eleni Chatzikyriakou

The radiation hardness of state-of-the-art silicon-on-insulator transistors of gate length dimensions of 90 nm and beyond is investigated. The combined effects of oxide charges and random fluctuations of the dopant atoms in silicon are considered. It is demonstrated that a parasitic channel forms at the interface of buried oxide and shallow trench isolation regions of the device and that this effect is aggravated by random dopant fluctuations.

Multi-objective design optimisation of coronary stents

Neil Bressloff, Georges Limbert (Investigators), Sanjay Pant

Stents are tubular type scaffolds that are deployed (using an inflatable balloon on a catheter), most commonly to recover the shape of narrowed (diseased) arterial segments. Despite the widespread clinical use of stents in cardiovascular intervention, the presence of such devices can cause adverse responses leading to fatality or to the need for further treatment. The most common unwanted responses of inflammation are in-stent restenosis and thrombosis. Such adverse biological responses in a stented artery are influenced by many factors, including the design of the stent. This project aims at using multi-objective optimisation techniques to find an optimum family of coronary stents which are more resistant to the processes of in-stent restenosis (IR) and stent thrombosis (ST).

Multimode simulation of high power fibre lasers and amplifiers

Peter Horak (Investigator), Ioannis Begleris

This project aims to address the challenge of ever-increasing demand for higher powers from fibre lasers by developing theoretical and numerical methods to simulate laser pulse amplification in large-mode area fibres supporting multiple spatial modes.

MXL Project

Mark Taylor, Junfen Shi (Investigators)

‘MXL’ is short for “Enhanced patient safety by computational Modelling from clinically available X-rays to minimise the risk of overload and instability for optimised function and Longevity”. This is an international EU-funded project which the Bioengineering Sciences Research Group at Southampton is involved in. For more information, visit http://www.m-x-l.eu

Nonequilibrium Dynamics of Atomic Gases in Optical Lattices

Sophie Marika Reed

Many-body, quantum systems exhibit emergent properties which allows for quantum events to influence properties on macroscopic scales. Such emergent properties are studied using stochastic phase-space techniques.

Nonlinear Optical Pulse Propagation

Peter Horak, Francesco Poletti (Investigators)

The work is concerned with the propagation of high-power short-pulse propagation in microstructured fibres or waveguides. Dispersion properties and optical nonlinearities are exploited for pulse shaping techniques in space, time, and frequency. Investigated microstructures include silica or soft-glass templates, gas-filled capillaries, and semiconductor-filled fibres, and optical wavelengths range from the X-ray to the mid-infrared regime.

Nonlinear Optics in Structured Material

Peter Horak, Neil Broderick (Investigators)

Structured materials such as photonic crystals, optical fibres, Bragg gratings etc. are the ideal material for nonlinear optics. Properly engineered materials allows one to control which nonlinear interactions are observed and enhanced whilst other nonlinear interactions can be neglected. This work looks both at fundamental ideas as well as the fabrication of devices for advanced telecommunications.

On the applicability of nonlinear timeseries methods for partial discharge analysis

Paul Lewin (Investigator), Lyuboslav Petrov

The governing processes of Partial Discharge (PD)
phenomena trigger aperiodic chains of events resulting in ’ap-
parently’ stochastic data, for which the widely adopted analysis
methodology is of statistical nature. However, it can be shown,
that nonlinear analysis methods can prove more adequate in
detecting certain trends and patterns in complex PD timeseries.
In this work, the application of nonlinear invariants and phase
space methods for PD analysis are discussed and potential pitfalls
are identified. Unsupervised statistical inference techniques based
on the use of surrogate data sets are proposed and employed for
the purpose of testing the applicability of nonlinear algorithms
and methods. The Generalized Hurst Exponent and Lempel Ziv
Complexity are used for finding the location of the system under
test on the spectrum between determinism and stochasticity. The
algorithms are found to have strong classification abilities at
discerning between surrogates and original point series, giving
motivation for further investigations.

Optical Characterisation of Black Silicon for Photovoltaics Using the Finite Element Method

Jack Tyson (Investigator)

Here we present a novel method of simulating the reflectance spectra of black silicon solar cells using the finite element method. Designed in COMSOL Multiphysics is a new set of algorithm-controlled-geometries rendering a vast array of different structural permutations of silicon nanowires. Our model focused on the variation of this geometry within customisable predefined conditions in large output quantities, collated and averaged to reliably determine the reflectance of an entire black silicon solar cell.

Origins of Evolvability

Richard Watson, Markus Brede (Investigators), William Hurndall

This project examined the putative evolvability of a Lipid World model of fissioning micelles. It was demonstrated that the model lacked evlovability due to poor heritability. Explicit structure for micelles was introduced along with a spatially localised form of catalysis which increased the strength of selection as coupling between potential chemical units of heredity were reduced.

Prediction of orifice flow flooding rates through generic orifices

Dominic Hudson, Ming-yi Tan (Investigators), Christian Wood, Adam Sobey

This presearch concentrates on the modelling of compartment flooding rates following the occurrence of damage in a ship's side shell. Typical state of the art flooding models use Torricelli’s formula to calculate flooding rates using a constant co-efficient of discharge (Cd). Based on Bernoulli’s theorem, turbulence and viscosity effects are not included using a Cd independent of damage shape or size. Previous work indicates that this assumption over-simplifies the problem to an extent where the flooding rates used for calculation are in error. This project will use CFD validated by experiment to calculate flooding rates for a large number of cases from which a 'krigged' response surface will be generated. Validity of the subsequent response surface will be interrogated.

Prediction of Psychopathology by MRT data

We aim to predict psychopathological outcomes in adults by functional brain data using multilevel regression and crossvaligdation strategies.

Pushing the Envelope of Planetary Formation and Evolution Simulations

Peter Bartram

A full understanding of the formation and the early evolution of the Solar System and extrasolar planetary systems ranks among natural science's grand challenges, and at present, even the dominant processes responsible for generating the observed planetary architecture remain elusive.

Real-time CFD for helicopter flight simulation

Kenji Takeda (Investigator), James Kenny

Project aims to show how real-time computational fluid dynamics (CFD) could be used to improve the realism of helicopter flight simulators.

Renormalisation group approach to 1D cellular automata with large updating neighbourhoods

Iain Weaver, Adam Prugel-Bennett (Investigators)

We study self-similarity in one-dimensional probabilistic cellular automata (PCA) by applying a real-space renormalisation technique to PCA with increasingly large updating neighbourhoods. By studying the flow about the critical point of the renormalisation, we may produce estimates of the spatial scaling properties of critical PCA.

Renormalisation of 2D cellular automata with an absorbing state

Adam Prugel-Bennett, Iain Weaver (Investigators)

We describe a real-space renormalisation scheme for non-equilibrium probablistic cellular automata (PCA) models, and apply it to a two-dimensional binary PCA. An exact renormalisation scheme is rare, and therefore we provide a method for computing the stationary probability distribution of states for such models with which to weight the renormalisation, effectively minimising the error in the scale transformation.

Simulation of biological systems at long length and distance scales

Jonathan Essex (Investigator), Kieran Selvon

This project aims to shed light on cell membrane mechanisms which are difficult to probe experimentally, in particular drug permiation across the cell membrane. If one had a full understanding of the mechanism, drugs could be designed to target particular embedded proteins to improve their efficacy, the viability of nano based medicines and materials could also be assessed, testing for toxicity etc.

Soft x-ray science on a tabletop

Peter Horak, Jeremy Frey, Bill Brocklesby (Investigators), Patrick Anderson, Arthur Degen-Knifton

Complex numerical simulations are being performed to aid experimentalists at Southampton realize the next generation of high brightness tabletop sources of coherent soft x-rays.?

Software Sustainability Institute

Simon Hettrick (Investigator)

A national facility for cultivating world-class research through software

Software helps researchers to enhance their research, and improve the speed and accuracy of their results. The Software Sustainability Institute can help you introduce software into your research or improve the software you already use.

The Institute is based at the universities of Edinburgh, Manchester, Oxford and Southampton, and draws on a team of experts with a breadth of experience in software development, project and programme management, research facilitation, publicity and community engagement.

We help people build better software, and we work with researchers, developers, funders and infrastructure providers to identify key issues and best practice in scientific software.

Statistical model of the knee

Mark Taylor (Investigator), Francis Galloway, Prasanth Nair

Development of methods for large scale computational testing of a tibial tray incorporating inter-patient variability.

Stochastic computational methods for aero-acoustics

Gwenael Gabard (Investigator), Martina Dieste

Stochastic methods are used to synthesize a turbulent flow which is then used to model the sound radiated by an airfoil interacting with this turbulence. This approach is faster than performing a complete simulation of the flow field.

Structured low-rank approximation

Ivan Markovsky

Today's state-of-the-art methods for data processing are model based. We propose a fundamentally new approach that does not depend on an explicit model representation and can be used for model-free data processing. From a theoretical point of view, the prime advantage of the newly proposed paradigm is conceptual unification of existing methods. From a practical point of view, the proposed paradigm opens new possibilities for development of computational methods for data processing.

The application of automated pattern metrics to surface moisture influences on modelled dune field development

Robin Wilson, Joanna Nield (Investigators)

Areas of sand dunes (known as dunefields) develop complex patterns over time. These are influenced by both the past and present environmental conditions, including surface moisture, vegetation distribution and human impact. This project develops a method of automated pattern analysis which allow the patterns produced by a large number of sand dune evolution simulations (performed using the DECAL model) to be quantified over time.

The effect of roughness upon turbulent supersonic flows

Neil Sandham (Investigator), Christopher Tyson

Understanding the interaction between surface roughness and supersonic air flows are crucial in the design of high speed vehicles, including space re-entry vehicles. Numerical simulations of these flows has been conducted in order to examine and understand how the surface roughness interacts with high speed flows in terms of drag prediction and heat transfer to the wall surface.

The Maximum Entropy Production Principle and Natural Convection

Seth Bullock, James Dyke (Investigators), Stuart Bartlett

In this project I wanted to perform some tests of the so-called Maximum Entropy Production Principle (MEPP) in the context of buoyancy-driven convection in a system with negative feedback boundary conditions.

The Origin of Aeolian Dunes (TOAD)

Joanna Nield (Investigator)

The overall aim of this project is to understand the genesis and subsequent evolution of aeolian early stage bedforms by quantifying for the very first time the role and importance of flow, transport and surface feedbacks in the initiation and emergence of dunes. This project offers the genuine prospect of surmounting arguably the major enduring research question within aeolian geomorphology, leading to broader insights which will offer knowledge benefits for sedimentary landform studies as a whole.

The response of the Bergmann glial cell to synaptic activity

Giles Richardson (Investigator), Stuart George

We model the potential changes induced in the Bergmann glial cell by synaptic activity in neighbouring neurons.

The Role of the Biota in the Carpenter Model on Lake Eutrophication

James Dyke (Investigator), Alexandra Diem

The Carpenter model is a useful and simple model to predict the eutrophication of shallow lakes via phosphorus input. This project aimed at resolving the function of the biota, which play a major role in the phosphorus dynamics, but are so far only implicitly modelled, and extending the model to explicitly represent them.

The tarsal intersegmental reflex control system in the locust hind leg

David Simpson, Philip Newland (Investigators), Alicia Costalago Meruelo

Locomotion is vital for vertebrates and invertebrates to survive. Despite that feet are responsible for stability and agility in most animals, research on feet movements and their reflexes is scarce.
In this thesis, the tarsal reflex responses of locust will be studied and modelled with ANNs to achieve a deeper comprehension of how stability and agility is accomplished.
The choice of ANNs is linked to the applicability of the method into other fields, such as technological designs or medical treatment.

Tipping points in Complex Coupled Life-Environment Systems

Iain Weaver, James Dyke (Investigators)

System-level homeostasis has been demonstrated in a number of conceptual, artificial life, models which share the advantage of a thorough and transparent analysis. We reintroduce a general model for a coupled life-environment model, concentrating on a minimal set of assumptions, and explore the consequences of interaction between simple life elements and their shared, multidimensional environment.

Today's Computation Enabling Tomorrow's Seamless Communication

Lajos Hanzo (Investigator), Varghese Thomas

Radio Over Fibre (ROF) is a communication technique that aims to gainfully amalgamate the benefits of optical and wireless communication, while keeping the system cost low. This technique would support the next generation of wireless services.

Transition to turbulence in high-speed boundary layers

Neil Sandham (Investigator), Nicola De Tullio

This work is focused on the numerical simulation of hypersonic transition to turbulence in boundary layers. We use direct numerical simulations of the Navier-Stokes equations to analyse the effects of different flow conditions and external disturbances on the transition process. The main objective is to gain insight into the different aspects of transition to turbulence at high speeds, which can lead to the design of new transition models and transition control techniques for high-speed flows.

Validation of a spatial-temporal soil water movement and plant water uptake model

Tiina Roose, Sevil Payvandi (Investigators), James Heppell

We develop a model that estimates the water saturation level within the soil at different depths, and the uptake of water by the root system. Data from Smethurst et al (2012) is used to validate our model and obtain a fully calibrated system for plant water uptake. When compared quantitatively to other models such as CROPWAT, our model achieves a better fit to the experimental data because of the simpler, first, second and third order terms present in the boundary condition, as opposed to complicated non-linear functions.

Vertical turbulence structures in the benthic boundary layer as related to suspended sediments

Hachem Kassem (Investigator), Charlie Thompson

There is a genuine need for better, more robust modelling of suspended sediment transport in the coastal zone, both to understand its morphological evolution and it's impact on biogeochemical cycling, ecosystems services and to guide engineering applications such as dredging and defence schemes against erosion and flooding.
The suspension of sediment in turbulent flows is a complex case of fluid-particle interaction, governed by shear stresses (momentum exchanges) at the bed and within the benthic boundary layer (BBL). The intermittent transfer of momentum is a manifestation of coherent turbulent vortex structures within the flow. The passage of such structures (or clusters of) is often related to perturbations of bottom sediment, which may be entrained and maintained in suspension if sufficient turbulent energy is provided. The first part of my PhD investigated the temporal and scale relationships between wave–generated boundary layer turbulence and event–driven sediment transport in oscillatory flow in the nearshore. This involved complex statistical, spectral, quadrant and wavelet analysis of high frequency nearshore measurements of turbulence and suspended sediments (medium sand), collected as part of the EU-funded Barrier Dynamics Experiment II (BARDEX II). The following step aims to develop a 3D numerical model in OpenFOAM which would reproduce the fine scale turbulence structures observed over a fixed rippled bed in oscillatory flow. The 3D velocity field, turbulent components, correlations (stresses) and quadrant structures will then be linked to observed sediment resuspension events. The model will be validated against a set of laboratory experiments undertaken at the Fast Flow Facility at HR Wallingford.

Vortices in Spinor Bose-Einstein Condensates

Janne Ruostekoski (Investigator), Justin Lovegrove

We numerically study the effect of spin degrees of freedom on the structure of a vortex in an atomic superfluid. Such objects are of interest as macroscopic examples of quantum phenomena, as well as for their analogies in other fields, such as cosmology and high energy physics.

Wave-based discontinuous Galerkin methods

Gwenael Gabard (Investigator), Greg Kennedy

Wave-based computational methods are developed to model sound propagation in moving inhomogeneous media.

µ-VIS Computed Tomography Centre

Ian Sinclair, Richard Boardman, Dmitry Grinev, Philipp Thurner, Simon Cox, Jeremy Frey, Mark Spearing, Kenji Takeda (Investigators)

A dedicated centre for computed tomography (CT) at Southampton, providing complete support for 3D imaging science, serving Engineering, Biomedical, Environmental and Archaeological Sciences. The centre encompasses five complementary scanning systems supporting resolutions down to 200nm and imaging volumes in excess of one metre: from a matchstick to a tree trunk, from an ant's wing to a gas turbine blade.