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.

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.

Summary The primary aim of this project is to produce new, sustainable oxidation catalysts that allow the creation of efficient wireless, photodiode, solar to chemical energy conversion devices for the splitting of brine/seawater. In brine, H2, alkali and Cl2 (or H2 and sodium hypochlorite, NaOCl will be the (separated) products. Hydrogen will be stored to provide heat at a later date (by burning) or used to produce electricity (via an H2/O2 fuel cell). The oxidised chloride will be stored either as Cl2, or hypochlorite, to provide a route to chlorinate water, or provide a disinfectant. The programme will produce inexpensive demonstrators which can be readily scaled up for use in the household - i.e. on a 'personalised' energy and disinfectant scale. Such systems are particularly suited for use in the developing countries, although the subsequent development of substantially scaled up systems - involving solar farms - will allow the production of these valuable, storable, chemical products at a level suitable for widespread use by a town and/or local industry. The latter scaled up systems will form the basis of a subsequent, second follow on stage, industry led, developmental program of work, whereas the first stage project described here will focus on the proof of concept and initial creation of scalable demonstrators. The proposed novel ClOCs developed in the project will utilise inexpensive, abundant nanomaterials (such as: oxides of Mn, Ni or Co), although, in some cases, these will be doped with well-dispersed, much more active, but less abundant ones, such as Ru dioxide. These nanomaterials will also be coated onto high surface area conducting carbons, which will allow them to be partly supported and active. A novel, combinatorial approach, using High-throughput Continuous Hydrothermal flow synthesis, HiTCH and, to a lesser extent, other - electrochemical and photochemical synthetic methods, will be used to produce a wide range of oxidation catalysts. Novel, colour-based rapid screening methods will be used to provide initial assessments of their activities and a wide range of techniques will be used to assess their physical properties. The best of the catalysts generated will be optimised in terms of performance as electrocatalysts and subjected to more detailed electro-kinetic and structural studies (e.g. XANES and XAFS) and subsequent mechanistic and structural modelling. This work will help identify key structural features associated with the most active of the electrocatalysts tested and inform on the best routes to be taken in the subsequent synthesis of related materials as oxidation catalysts of possible greater potential. Finally, the best of all the electrocatalysts tested will be used to create simple, exemplar, scalable working wireless photodiode solar energy conversion devices, which utilise inexpensive, efficient, triple-junction Si photovoltaic cells as the light-absorbing unit, for the photocleavage of water or brine (including seawater).

This project is both multi-scale and multi-disciplinary, and spans research areas across physics, mechanical engineering, computer science and chemical engineering. Our aim is to produce, for the first time, a general, robust and efficient open-source code for the simulation of non-continuum flows for engineering applications. Such flows are vital to the performance of a number of potentially transformative future technologies (e.g., highly-efficient sea-water desalination using membranes of carbon nanotubes, and nano-structured hydrophobic surfaces for marine drag reduction) but they cannot be simulated using conventional continuum-fluid simulations. Our work exploits the core methodological advances emerging from the EPSRC Programme Grant "Non-equilibrium Fluid Dynamics for Micro/Nano Engineering Systems" (EP/I011927/1), which have demonstrated exciting potential in the multi-scale modelling of non-continuum flows using hybrid continuum-particle methods. The software developed in this project builds on the already widely-adopted open-source code OpenFOAM for computational fluid dynamics. In capitalising on a) the success of the UK's OpenFOAM software and b) the EPSRC's Programme Grant investment in a strategic research area, this project aims to bring sustainability to both.