Large Eddy Simulation (LES) is gradually replacing traditional Reynolds-averaged-Navier-Stokes (RANS) modelling as the method of choice for predicting complex turbulent flows in research as well as industrial practice. This is especially so when unsteady phenomena are to be resolved (vibrations, acoustics, thermal striping, pressure peaks). However, the exploitation of LES for predicting practical wall-confined flows, particularly those involving separation from curved surfaces, is seriously inhibited by practically untenable resource requirements at high Reynolds numbers. Hybrid LES-RANS schemes, employing some form of RANS-like solution in the near-wall region, are generally regarded as a compromise strategy circumventing the resource obstacle. Existing schemes are based on the use of RANS models that operate in unsteady mode, as they are subjected to high amplitude, high-frequency fluctuations imposed on the layer by the outer LES solution. These models thus operate far outside their intended range of applicability. Moreover, in most approaches, the small-scale motions not resolved explicitly by the LES are represented by an ill-defined blend of subgrid-scale and RANS turbulence models - i.e. there is no clear dividing line between the LES and RANS components. Not surprisingly, such models display a whole range of disconcerting defects.This submission proposes a collaboration between two groups who have been at the forefront of developing RANS-LES schemes in the UK. Indeed, the two groups are the only UK academic partners who have participated in the four-year EU FP6 project DESider, specifically devoted to RANS-LES modelling for industrial applications, and in the follow-up 22-partner FP7 project ATAAC (Advanced Turbulence Simulation for Aerodynamic Application Challenges). Electricite de France (EDF) will support the programme to the level of one man-year of PDRA.The proposed project aims specifically at LES-RANS hybrids that distinguish carefully between the LES and RANS elements, each applied subject to appropriate, well-established constrains and coupled rationally. The project involves two major strands: (i) the development of a novel zonal (two-layer) scheme, which entails the solution of steady, parabolized RANS equations, subject to on-the-fly time-averaged constraints derived from the LES solution, and the use of an anisotropy-resolving turbulence model over a thin near-wall layer superimposed onto the LES domain; (ii) the integration and validation of (i), as well as an extended version of a newly-developed RANS-LES hybrid (Uribe et al [2007]), which shares some basic concepts with proposed model under (i), into a state-of-the-art numerical framework (Saturne), which is promoted by EPSRC's CCP12 as a general prediction tool for computing turbulent flows in very complex geometries on HPCx and HECTOR. A key characteristic of Uribe et al's model is that it respects the need to separate the RANS-derived Reynolds stresses from the inherently unsteady LES, and to desensitize the resolved perturbations and the subgrids-scale stresses from the RANS model. To that extent, the model is based on the same philosophy underpinning the zonal scheme to be developed, although the two models differ radically in respect of their design.

The DEMAND Centre (Dynamics of Energy, Mobility and Demand) takes a distinctive approach to end use energy demand, recognising that energy is not used for its own sake but as part of accomplishing social practices at home, at work and in moving around. In essence the Centre focuses on what energy is for. This approach generates an ambitious research agenda that is crucial for organisations involved in demand management and in radically reconfiguring infrastructures, buildings and transport systems in line with greenhouse gas emissions targets. While greater efficiency is important, the trend is often towards more resource intensive standards of comfort, convenience and speed. The problem is that we lack a sophisticated understanding of how these trends take hold and of the underlying dynamics of demand itself. In focusing on how demand is made and met, the Centre will work across the sectoral boundaries of mobility and building-related energy use. To do this it will draw on academic experts from many disciplines, and on the research and practice based knowledge of a major international energy company, EDF, which shares our ambition to understand much more about the fundamental dynamics of energy demand. The five themes of our research programme will produce a coherent and integrated set of outcomes. Theme 1 will generate a detailed and differentiated analysis of trends and patterns in end use practices, working across sectors by combining existing data in new ways. Theme 2 will provide in-depth explanations of how and why end use practices are changing to produce an increase or decrease in demand, assessing the implications for scenarios and for current and new forms of demand management. Theme 3 will examine the scope for managing energy demand through the design and operation of infrastructures, identifying which features of present energy and mobility systems might be abandoned, adapted and augmented over the next 40 years. Theme 4 focuses on where and how notions of need and of justice and entitlement to energy services have become embedded in legislation, regulation and norms, and how these might be changed. The fifth theme addresses three cross cutting issues: the constitution of demand (how is energy demand made?); the dynamics of demand (how does it change?) and steering demand (how, when, and by whom can patterns of energy demand be shaped and steered?). The Centre's structure - a core group, a close knit research team and an extended network - provides the necessary focus and flexibility. Members of the core group from Lancaster University, the Institute for Transport Studies at Leeds University, and EDF R&D have established track records in energy-related research and leadership. EDF R&D's European Centre and Labs for Energy Efficiency Research (ECLEER) is embedded in the Centre, committed to its agenda and approach and consequently contributing over £1.35 million of co-funding. Managing demand is a task that depends on the combined efforts of utilities, governments (at every level), and those involved in making, modifying and managing buildings and transport systems. We will therefore collaborate with Transport for London, the International Energy Agency, DECC and SCI/Tesco, along with a DEMAND club of non-academics involved with our research and its dissemination, and an extended network of national and international experts from academia, business and policy, all working together to develop the Centre's research, to ensure its practical value and impact and to provide a focal point for new forms of cross-sectoral exchange and innovation. The Centre also includes 20 visiting fellowships, a series of additional linked projects, together with a PhD programme (9 students), an internship and related summer schools. These arrangements ensure that the centre acts as a "hot house" for academic and non-academic creativity, providing opportunities to co-design novel analyses and practical interventions

Fluid dynamics underpins large areas of engineering, environmental and scientific research, and is becoming increasingly important in medical science. At Leeds, we possess research expertise across each of these domains and we have an established record of working across disciplinary boundaries. This proposal builds upon this record through the establishment of a multidisciplinary CDT in Fluid Dynamics. Research techniques that will be applied, and developed, will encompass: mathematical modelling & theory; numerical methods, CFD & high performance computing (HPC); and measurement & experimentation. Engineering application areas to be addressed include: reacting flows; carbon capture, transport & storage; flow of polymer melts; mixing problems; particulate flows; coating & deposition; lubrication; medical devices; pathogen control; heat transport; wind turbines; fluid-structure interaction; and nuclear safety. Environmental application areas will consist of: groundwater flow; river/estuary flows; tidal flows; oceanography; atmospheric pollution; weather forecasting; climate modelling; dynamics of the Earth's interior; and solar & planetary flow problems. Facilities available to undertake this research include: the University's HPC system which, combined with the N8 regional facility that is hosted at Leeds, provides ~10000 computational cores, an extensive suite of licensed software and dedicated support staff; flow measurement techniques (including Particle Imaging Velocimetry (PIV), 2-component Laser Doppler Anemometry (LDA), Phase Doppler Anemometry (PDA) and Ultrasonic Doppler Velocity Profiling (UDVP)); techniques for measuring fluid concentration (Ultrasonic High Concentration Meter (UHCM) and Optical Backscatter Probes (OBS)) and a range of optical metrology systems (e.g. pulsed and continuous wave lasers). The UK has a substantial requirement for doctoral scientists and engineers who have a deep understanding of all aspects of fluid dynamics from theory through to experimental methods and numerical simulation. In manufacturing and process engineering, for example, many processes depend critically on fluid flows (e.g. extrusion of polymer melts, deposition of coatings, spray drying, etc.) and it is essential to understand and control these processes in order to optimize production efficiency and reliability (see letter of support from P&G for example). In large-scale mechanical engineering there is a demand for expertise in reacting turbulent flows in order to optimize fuel efficiency and engine performance, and in wetting and surface flows for the design and manufacture of pumps and filters. There is also a need for a wide variety of skilled experts in environmental fluid flows to support the growing need to understand and predict local pollution and threats to safety (atmospheric, surface water, ocean and sub-surface flows), and to predict weather, climate and space weather for satellite technology. We will train a new generation of researchers who will have a broad range of skills to transfer into industry and environmental agencies, hence our approach will be multi-disciplinary throughout. All students will undertake both modelling and experimental training before embarking on their PhD project - which will be co-supervised by academics from different Schools. The MSc component of the programmee will be specifically tailored to develop expertise in the mathematical background of fluid dynamics, in CFD/HPC, and in experimental techniques. Team-based projects will be used to develop the teamwork and communication skills we believe are essential. Finally, engagement with industry will be a key feature of this CDT: all students will undertake an industrial placement, a large number of projects will be industrially sponsored, and our non-academic partners will contribute actively to our management, implementation and strategic development.

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

Floating offshore wind turbine (FOWT) deployments are predicted to increase in the future and the outlook is that globally, 6.2 GW of FOWTs will be built in the next 10 years (https://tinyurl.com/camyybxk). Highly dynamic, free hanging power cables transport power generated by these FOWTs to substations and the onshore grid. Safety critical design of such power cables in order for them to operate in the ocean without failure is of utmost importance, given that these cables are highly expensive to install and replace and any down-time of turbine electrical output results in huge revenue loss. In FOWTs, a large length of the power cable, from the base of the floating foundation to the seabed, is directly exposed to dynamic loading caused by ocean waves, currents, and turbulence. Waves move the floating foundation, and currents produce cable oscillations generated by vortex shedding. In the water column a cable experiences enhanced dynamic loads and undergoes complicated motions. When a dynamic cable is installed in deep water, the upper portion of the cable is exposed to high mechanical load and fatigue, and the lower part to substantial hydrostatic pressure. Motion of the floating foundation in surge, sway, and heave causes the power cable to undergo oscillatory motions that in turn promote vortex-induced vibration (VIV) - which is analogous to the vibration experienced by long marine risers used in offshore oil and gas platforms. As a result, large and complex deflections of the cable occur at various locations along its length, altering its mechanical properties and strength, and eventually leading to fatigue-induced failure. The dynamic forces produce cyclical motions of the cable, and a sharp transition in cable stiffness is expected in cases where these motions and loads concentrate toward a rigid connection point. Repetition of the foregoing process and over-bending can also lead to fatigue damage to the cable. To date, hardly any research has been undertaken to investigate the 3-dimensional nature of VIV, dynamic loads, and motion of power cables subject to combined waves, currents, and turbulence. Moreover, no detailed guidance is given in design standards for the offshore wind industry on how to predict, assess, and suppress fatigue failure of dynamic cables under wave-current-turbulence conditions. Power cable failure is much more likely to occur if the design of such cables is based on poor understanding of the hydrodynamic interactions between cables and the ocean environment. This fundamental scientific research aims to investigate the dynamic loading, motion response, impact of vortex induced vibration and its suppression mechanism, and fatigue failure of subsea power cables subjected to combined 3-dimensional waves, currents, and turbulence. This research will be approached by both numerical and physical modelling of power cable's response. Controlled experimental tests on scale models of power cables will be undertaken in Edinburgh University's FloWave wave-current facility where multi-directional waves and currents of various combinations of amplitudes, frequencies, and directions can be generated. Advanced novel phenomenological wake oscillator models, calibrated and validated with FloWave experimental results, will be used to simulate the hydrodynamic behaviour of power cables. The resulting software tools, experimental data, analysis techniques for characterising cable dynamics and VIV, methodologies established for fatigue analysis, and other outcomes of this research will enhance the design of cost-effective power cables. By reducing uncertainty, our research will lead to increased reliability of offshore power cables, of benefit to the power cable manufacturing industry.