A majority of engineering and environmental flows occur over surfaces that exhibit spatial variations in roughness and/or topography. When a turbulent wall-flow evolves over such surfaces, it may exhibit unusual physical properties, depending on the relationship between the dominant length-scales of the surface and that of the flow. Specifically, when the dominant length-scale(s) of the surface in the cross-stream direction become(s) comparable to the dominant length-scale of the flow (such as boundary layer thickness or water-depth), then the flow also exhibits large-scale spatial heterogeneity that is locked-on to the surface heterogeneity. This flow heterogeneity is expressed in the form of localised secondary currents (SCs) that often extend across the entire depth of the flow and manifest themselves as large 'time-averaged' streamwise vortices accompanied by low- and high-speed regions. This surface-induced flow heterogeneity invalidates some of the fundamental tenets of turbulent wall-flows that were developed for flows over homogeneous surfaces. Therefore, current predictive tools that rely on these tenets can neither accurately predict nor offer insights into the complex physics of flows that contain surface-induced SCs. The significant effects of surface-induced SCs have recently been recognised in at least two disparate areas: 1) Performance of engineering systems such as in-service turbine blades, bio-fouled ship hulls and flow control; and 2) Understanding of the river flow dynamics with applications in flood management, eco-hydraulics and sediment transport. Over recent years, Southampton, Aberdeen, Glasgow and UCL have invested considerable efforts in advancing both these areas. Given the burgeoning interest in this topic, it would be timely to harness the synergies between these four leading groups to develop comprehensive understanding of turbulent flows in the presence of surface-induced SCs and establish a novel transformative framework to predict such flows. This project will leverage the expertise, domain knowledge and infrastructure of four leading groups in the above-mentioned areas to bring about a paradigm shift in our approach to flows over heterogeneous surfaces that generate secondary currents. A comprehensive series of physical experiments (at Southampton & Aberdeen) and complementary numerical simulations (at Glasgow & UCL) will be performed to generate unprecedented data on surface-induced SCs. We will compare and contrast the behaviour of SCs across all four canonical wall-flows (boundary layers, open-channels, pipes and closed-channels) for the first time. The obtained data will underpin identification and validation of potential universalities (and differences) in drag mechanisms and momentum/energy transfer in these flows in the presence of surface-induced SCs. Synthesising the insights obtained from the data, a new framework leading to physics-informed semi-empirical and and theoretically-based numerical models will be developed to predict and optimise the influence of surface-induced SCs on turbulent wall-flows relevant to engineering/environmental applications.

In 2010 an international roundtable discussion, entitled " The Plus or Minus Debate", was held between 600 conservators, scientists and collections care professionals to explore and re-evaluate the environmental guidelines, advances in environmental research and the implications for collections, archives and libraries. The impetus for this meeting was the realisation that efficient environmental control has become essential in the light of the future energy crisis, the worldwide economic downturn, and a rising awareness of green technology. For over four decades the environmental guidelines for museums and institutions have been defined within narrow parameters. Conditions for multi-layer painted wooden objects in particular are amongst the most tightly controlled. We have empirical evidence (warping and splitting wood, cracking and delamination of paint) that these objects are vulnerable to continual environmental changes mainly because of the hydroscopic response of wood. However, we have yet to establish a correlation between environmental changes, the variations in the original preparation layers and the resulting different crack patterns or delamination at particular interfaces. Nor do we have sufficient data to reliably use crack patterns as indicators of particular mechanical failures within the structure. This project aims to highlight the mechanisms which lead to initiation and propagation of cracks as a result of environmental conditions in painted wooden cultural heritage, and how these eventually lead to delamination of the painted surface or underlying layers. This damage can lead to loss of the image or motif, resulting in changes to the aesthetic of the work, change in meaning and appreciation of the viewer. Compositional differences in the preparation and paint layers mean that the possible interfaces at which cracks can initiate are considerable. In the past it was assumed that if the environmental conditions do not cause deformation of the object beyond its ultimate tensile strain then no permanent damage will occur. However, fatigue is a possible long term problem where objects are continuously subjected to small environmental changes even within a limited range of temperature and relative humidity. It is therefore timely to undertake research to understand under what conditions environmentally induced fatigue could lead to delamination of painted surfaces in wooden objects. The methodology will be established considering multiple paint systems on wood. These systems are also found on polychrome sculpture, painted musical instruments, ethnographic objects and contemporary art. This will be achieved by an interdisciplinary project which will include determining the history of cyclic strain based on moisture and thermal deformation and the induced failure in different layers. The temperature, moisture and strain rate dependent (viscoelastic) properties of the constituent materials of the objects make this research a particular challenge both for the modelling and experimental testing. Published data and data collected from specific collections of environmental fluctuations, plus measured deformations of panel paintings, will be used as parameters for experimental fatigue testing. This simulates real fluctuating conditions but at a higher frequency: to a first approximation, this is equivalent to the induced deformations caused over hundreds of years of environmental changes. These results will be used to validate the modelling. Finally, accurate predictions for the lifetime of the painted panels will be made and compared to the Bizot (a group of the world's leading museums) 2015 guidelines for environmental control to ascertain what effects they might have on the condition of these objects. The research will provide experimental and simulation data of fatigue lifetimes for panel paintings and related cultural heritage that can be used to inform strategies for environmental control and collections care.

A major challenge in the development of more sustainable polymeric materials for industrial manufacturing processes (such as coating or molding) for commodity products is how to ameliorate the need to manipulate the material at elevated temperatures (so it can flow and be shaped as a liquid) whilst maintaining desirable mechanical properties of the polymer (e.g. strength and toughness) at room temperature in the finished article. Processes such as injection molding or hot-melt adhesive application require elevated temperatures (often greater than 200 degrees Celsius) and thus represent capital-intensive, energy-consuming, production technologies which in turn inflate the cost and carbon-footprint of the final product. The ability to manipulate polymers at relatively modest, and controllable, elevated temperatures (sub 100 degrees Celsius) would represent significant savings of energy and cost. This proposal describes a route to novel supramolecular materials that can be processed in this manner and will also offer recyclable characteristics. The project will investigate the physical and mechanical properties of new supramolecular polyurethanes and their composite materials in order to generate a new generation of adhesives and surface coatings. Supramolecular polymers are relatively short chain organic materials that are held together by many non-covalent interactions such as hydrogen bonding, to afford polymers of far higher molecular mass and, as a consequence, these systems exhibit many solid-state characteristics common to 'traditional' covalent bonded polymers (e.g. strength and stiffness). However, as a consequence of the relatively weak non-covalent interactions that hold the supramolecular polymers together, these materials can be dissociated easily into their individual contributing components by the application of a suitable (relatively modest) stimulus - e.g. heat or light. In this project we will also harness the thermal cycling potential of supramolecular polyurethanes in conjunction with the enhanced strength and toughness offered by fibrous and particulate fillers by developing novel supramolecular polymer composites. Such materials are potentially attractive as easily-applied adhesives and tough, corrosion resistant and healable coatings for metals and electronic components. The field of supramolecular composites is in its infancy and has yet to gain significant coverage in the literature and thus this proposal is very timely. Furthermore, the well-defined chemistry of the supramolecular polyurethanes and the composites formed from them will be used in conjunction with mechanical measurements to construct a solid-melt constitutive model parameterized in terms of the chemical structure of the supramolecular polyurethanes. In doing so, a predictive tool will be generated, suitable for design of further supramolecular materials, targeted at specific thermo-mechanical properties.

Many industrial formulations that form part of our daily lives are complex mixtures. These include food, hygiene and laundry products, paints, etc. In many of these systems small molecules migrating to and across interfaces (that are either exposed to atmosphere or buried in bulk) leads to undesired effects. These might include adhesive loss in hygiene products, poor flavour perception, and release of undesired chemicals to the atmosphere. This project is aimed at developing a software toolkit for understanding small molecule migration in complex fluid mixtures that have many ingredients. Our ambition is to go far beyond the very simple model systems for which molecular migration has previously been characterised, and to address the complexities that arise when migration occurs in products that have structure, or are evolving with time. This brings fascinating but subtle challenges which are not only stimulating fundamental problems, but underpin 'real world' issues such as shelf-life of detergent formulations, durability of coatings and even how our food tastes when we chew it. We have developed this proposal in close collaboration with 3 industrial partners (P&G, AkzoNobel and Mondelez) who represent three very different sectors of the consumer goods industry, yet have in common the need to control migration in structured products. Despite working on entirely different product ranges, scientists in these companies share a remarkable range of problems that can be addressed by answering 3 key questions: Q1. How does the depth profile of wetting layers and subsurface concentrations depend on bulk phase composition and molecular interactions? Q2. What is the surface structure resulting from lateral migration? Q3. What are the timescales and mechanisms associated with migration and formation of surface structures? We will tackle these questions for a variety of carefully defined model formulations to isolate influences of polarity, charge, hydrophobicity, elasticity and deformation, in a series of fundamental studies. The project will deliver fundamental science knowledge along with a predictive model toolkit, ready to be embedded in the research programmes of soft matter scientists and technologists. We will work with our industrial partners throughout the project to ensure successful implementation of these models to allow them to exploit this work in their R&D programmes, and make the deliverables available to wider downstream users through a supported software website and the National Formulation Centre. Solving these problems will pave the way to efficient formulations that offer reduced waste improved performance and stability in consumer goods.

It is interesting to speculate that Nelson's victory at Trafalgar was due to an absence of biofouling on the ship's hulls (which were made of copper, a known biocide) allowing them superior speed.Biofouling is the undesirable accumulation of microorganisms, algae etc which occurs on submersed structures. The effects of biofouling are considerable; increased frictional drag, leading to increased fuel consumption and associated CO2, SOx, NOx emissions; restrictions in internal pipe dimensions leading to loss of flow, increased pressure and poor heat exchange in pipelines and commonly, the development of biofilms that provide habitats for the development of aggressive micro climates that are extremely acidic and lead to rapid rates of corrosion and structural failure, e.g., BP Purdoe Bay pipeline failure was due to microbial induced corrosion (MIC).The aim of this project is to commercialise a non-biocidal antifouling coating. The coating is based upon the concept that 'protective bacteria' encapsulated within a sol-gel matrix, and applied to a surface, will prevent harmful biofilms forming on that surface. The 'protective bacteria' in this case consist of endospores that are naturally ocurring in soil and are non-pathogenic. The concept has been proven in an EPSRC project that will end in October 2010.We propose to work with selected partners who manufacture coatings for the key markets that utilise antifouling coatings. The partners will help with commercial performance testing that will allow us to benchmark our coating against current commercially available coatings. We will address the requirement for the coating to be applied under industrial conditions to large surface areas and the feasibility of applying our coating on top of existing marine coatings that are applied to prevent corrosion. Importantly we will address the issue of scale-up of manufacture, particularly that of endospore production, something that traditional coating manufacturers are not familiar with. The partners will also advise on Health & Safety issues and provide guidance on regulatory requirements of the coating.