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This short communication summarises recent developments and ongoing work on Hybrid RANS-LES Methods (HRLM) at The University of Manchester. Our work is focussed primarily on the development of coupled zonal methods, investigating improvements and novel applications of embedded turbulence simulation via the Synthetic Eddy Method. These activities are centred around the premise that no single modelling methodology will be generally applicable. Not only does this apply to different test cases, but for particular regions of the flow within a single test case. Similarly, when factoring in the computational resources available to the modern-day CFD practitioner, a framework for multifidelity approaches seems pragmatic. The work presented herein is intended primarily as a window through which we outline our current activities, mostly driven by PhD projects, many of which with industrial projects in mind. We also introduce recent developments focused on using the lattice Boltzmann method as part of a coupled Hybrid RANS LES approach.

One of the key developments of the marine energy industry in the UK is the demonstration of near commercial scale devices in real sea conditions and the collection of performance and environmental data to inform permitting and licensing processes.The ETI’s ReDAPT (Reliable Data Acquisition Platform for Tidal) project saw an innovative 1MW buoyant tidal generator installed at the European Marine Energy Centre (EMEC) in Orkney in January 2013.The project demonstrated the performance of the tidal generator in different operational conditions, aiming to increase public and industry confidence in tidal turbine technologies by providing a wide range of environmental impact and performance information, as well as demonstrating a new, reliable turbine designThis presentation by the University of Manchester describes development of a CFD model of the TGL turbine and a detailed study of transient flow and loads. It coversMD1: Development of a CFD model of the TGL turbine at the EMEC site.Methods:Sliding Mesh Method developed for RANS and LESSynthetic Eddy Method used to represent depth profile of mean and unsteady flowLES with sliding mesh method and SEM inflow to predict 1 MW turbine loadsFindingsAccurate prediction of power and thrustMeasured shear significantly affects cyclic blade loadingLES with SEM inflow predicts blade root bending moment affecting fatigue designAim Achieved: To establish capability of CFD for unsteady load prediction in realistic flowsLessons and Next Steps

One of the key developments of the marine energy industry in the UK is the demonstration of near commercial scale devices in real sea conditions and the collection of performance and environmental data to inform permitting and licensing processes.The ETI’s ReDAPT (Reliable Data Acquisition Platform for Tidal) project saw an innovative 1MW buoyant tidal generator installed at the European Marine Energy Centre (EMEC) in Orkney in January 2013.The project demonstrated the performance of the tidal generator in different operational conditions, aiming to increase public and industry confidence in tidal turbine technologies by providing a wide range of environmental impact and performance information, as well as demonstrating a new, reliable turbine designThis document represents deliverable MD1.4 and describes the application of EDF’s open-source CFD solver Code_Saturne to large-eddy simulations (LES) of a full-scale tidal-stream turbine (TST). All simulations were performed with realistic approach-flow mean-velocity profiles.The objective of the work was to supplement this with realistic approach-flow turbulence and to extract frequency spectra of the fluctuating loads. LES was conducted with both zero inlet turbulence and with a fluctuating velocity field synthesised from the stress profiles and length scales generated by a fully-developed channel-flow simulation. Turbulence profiles were further scaled to represent field measurements more accurately.The simulations follow on from Reynolds-averaged Navier-Stokes (RANS) computations reported earlier in MD1.5, but allow a more comprehensive evaluation of fluctuating loads on the turbine

One of the key developments of the marine energy industry in the UK is the demonstration of near commercial scale devices in real sea conditions and the collection of performance and environmental data to inform permitting and licensing processes.The ETI’s ReDAPT (Reliable Data Acquisition Platform for Tidal) project saw an innovative 1MW buoyant tidal generator installed at the European Marine Energy Centre (EMEC) in Orkney in January 2013.The project demonstrated the performance of the tidal generator in different operational conditions, aiming to increase public and industry confidence in tidal turbine technologies by providing a wide range of environmental impact and performance information, as well as demonstrating a new, reliable turbine designThis document provided details of a Computational Fluid Dynamics (CFD) method to model a full tidal-stream turbine simulation, with realistic ambient turbulent flow conditions. Modelling includes simulation of the 1MW TGL turbine at a fixed rotation rate, including effects of turbulence and meanflow velocity shear with realistic ebb and flood profiles from the EMEC test site. High-resolution channel flow calculations have characterised mean velocity, turbulence and length scales

One of the key developments of the marine energy industry in the UK is the demonstration of near commercial scale devices in real sea conditions and the collection of performance and environmental data to inform permitting and licensing processes.The ETI’s ReDAPT (Reliable Data Acquisition Platform for Tidal) project saw an innovative 1MW buoyant tidal generator installed at the European Marine Energy Centre (EMEC) in Orkney in January 2013.The project demonstrated the performance of the tidal generator in different operational conditions, aiming to increase public and industry confidence in tidal turbine technologies by providing a wide range of environmental impact and performance information, as well as demonstrating a new, reliable turbine designThis document is the second in a series describing progress with the application of EDF’s open-source CFD solverCode_Saturne toward a full marine-current-turbine simulation, including turbulence and waves. Reynolds-averaged-Navier-Stokes (RANS) calculations with the standard k- turbulence model and large-eddy-simulation (LES) calculations with the Smagorinsky model and a basic synthetic eddy model (SEM) for inflow turbulence are reported. Generally results show good correlation with experimental data for thrust coefficient but poor correlation with power coefficient

WOS: 000273877000005, The turbulent flow inside a low-speed centrifugal compressor at design condition is investigated using large-eddy simulation (LES) comprising of up to 26x10(6) computational volume cells. Unlike in the past, the current study's special emphasis is placed on the turbulence field evolution inside the impeller. LES predictions suggest that the Boussinesq hypothesis does not seem to be valid, especially near the exit of the impeller where the blade unloading takes place. Reynolds stress variations show a tendency toward an "axisymmetric expansion" type of turbulence after the impeller exit for which the subgrid-scale stress contribution shows a monotonic decrease. Probability density function analysis for the leakage flow show that instantaneous velocities in the wake region are less intermittent as compared with those in the jet. Time spectra analysis display also another feature that the energy cascade proceeds at a higher rate and lasts longer in the wake region than in the tip jet region., NASA, The authors would like to thank to Dr. Michael D. Hathaway from NASA for providing the experimental data for the centrifugal compressor.

WOS: 000258485300004, The laminarization phenomenon for the flow under the combined effect of strong curvature and rotation is discussed based on numerical predictions of large-eddy simulation (LES). Initially, the laminarization process is presented for the fully developed flow inside a spanwise rotating straight square duct. LES predictions over a wide range of rotation numbers (Ro=0-5) show that the turbulent kinetic energy decreases monotonically apart from 0.2 < Ro < 0.5. Subsequently, a spanwise rotating U-duct flow is considered with Ro=+/- 0.2. The interaction of curvature and Coriolis induced secondary flows enhances the turbulence for the negative rotating case, whereas this interaction ensues strong laminarization for the positive rotating case. Finally, the laminarization is presented in the impeller of a typical centrifugal compressor, rotating at a speed of Omega=1862 rpm (Ro=0.6). The resulting LES predictions are observed to be better than those of Reynolds-averaged Navier-Stokes (RANS) in the regions where turbulence is significant. However, for the regions dominated by strong laminarization, RANS results are seen to approach those of LES and experiments.