64 research outputs found
Correction to: Sloshing wing dynamics - 2nd year project overview
No full textCorrection Notice Alex Skillen added to the Author list as he contributed significantly to the project and paper
Correction: Sloshing Wing Dynamics - 2nd Year Project Overview
No full textCorrection Notice Alex Skillen added to the Author list as he contributed significantly to the project and paper.</p
3D datasets for "Thermal transients in a U-Bend"
No full textData accompanying the manuscript "Thermal transients in a U-Bend" submitted to the International Journal of Heat and Mass Transfer (IJHMT) July 2019. 3D volumetric cell-centre data, in vtk format (readable by Paraview, https://www.paraview.org/, for instance) at times \tilde{t}=0, 15, 30, 45, and 70 are enclosed. The file names are {SOLID|FLUID}_t{N}.vtu which denote data for either the fluid or solid domain at time \tilde{t}=N.
The field variables comprise:
"T"; the ensemble averaged normalised temperature.
"V"; the ensemble averaged normalised velocity.
"uu", "uv", etc.; the ensemble averaged resolved Reynolds stress components, normalised by bulk velocity.EP/R029326/
The overset grid method, applied to the solution of the incompressible Navier-Stokes equations in two and three spatial dimensions.
No full textA high-order finite-difference solver for direct numerical simulations of magnetohydrodynamic turbulence
No full textThis paper presents the development and validation of a Magnetohydrodynamics (MHD) module integrated into the Xcompact3d framework, an open-source high-order finite-difference suite of solvers designed to study turbulent flows on supercomputers. Leveraging the Fast Fourier Transform library already implemented in Xcompact3d, alongside sixth-order compact finite-difference schemes and a direct spectral Poisson solver, both the induction and potential-based MHD equations can be efficiently solved at scale on CPU-based supercomputers for fluids with strong and weak magnetic field, respectively. Validation of the MHD solver is conducted against established benchmarks, including Orszag-Tang vortex and MHD channel flows, demonstrating the module's capability to accurately capture complex MHD phenomena, providing a powerful tool for research in both engineering and astrophysics. The scalability of the Xcompact3d framework remains intact with the incorporation of the MHD module, ensuring efficient performance on modern high-performance clusters. This paper also presents new findings on the evolution of the Taylor-Green vortex under an external magnetic field for different flow regimes
Resubmitted Figures and Tables from the journal article: "On the numerical modelling of frozen walls in a molten salt fast reactor"
No full textThe data enclosed in this repository is associated with the manuscript for an article "On the numerical modelling of frozen walls in a molten salt fast reactor" resubmitted to the Nuclear Engineering and Design Journal in August 2019. The article was selected for the CFD4NRS-7 Special Issue of the Journal. The data in the article was presented at the CFD4NRS-7 Workshop in Shanghai, September 2018 and the NUTHOS-12 topical meeting in Qingdao, October 2018.
References:
G.M. Cartland-Glover, A. Skillen, D. Litskevich, S. Rolfo, D.R. Emerson, B. Merk, C. Moulinec. "On the numerical modelling of frozen walls in a molten salt fast reactor". In proceedings of the OECD/NEA&IAEA CFD4NRS-7 Workshop, Application of CFD/CMFD Codes to Nuclear Reactor Safety and Design and their Experimental Validation, Shanghai, September 4-6, 2018.
G.M. Cartland-Glover, A. Skillen, S. Rolfo, D.R. Emerson, C. Moulinec, D. Litskevich, B. Merk. "On the feasibility of the application of frozen walls to a molten salt fast reactor". In proceedings of the 12th International Topical Meeting on Nuclear Reactor Thermal-Hydraulics, Operation and Safety -- NUTHOS-12, Qingdao, China, October 14-18, 2018.
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The data is in the form of figures and tables.
The figures in the corresponding directory were prepared using bash scripts, python version 2.7, gnuplot version 4.6 and latex to extract and analyse simulated data.
The tables in the corresponding directory were prepared using bash scripts and python version 2.7 to extract and analyse simulated data.
The python scripts can be found in the repository. Note that numpy is a requirement.
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The raw data was prepared using the SCARF (scarf.rl.ac.uk), CIRRUS (cirrus.ac.uk), University of Liverpool (https://www.liverpool.ac.uk/csd/advanced-research-computing/facilities/high-performance-computing/) and SCAFELLPIKE (http://community.hartree.stfc.ac.uk/wiki/site/admin/home.html) clusters. There is inexcess of 10Gb of data generated by the solvers Code_Saturne (https://www.code-saturne.org/cms/), DYN3D-MG (https://www.hzdr.de/db/Cms?pOid=11771&pNid=542) and SERPENT (http://montecarlo.vtt.fi/).
Code_Saturne (version 5.0) was used to perform simulations of thermal fluid dynamic and conjugate heat transfer of a molten salt fast reactor. The models studied the formation of frozen salt films on cooled reactor vessel walls.
DYN3D-MG modelled the nodal diffusion neutronic behaviour of the molten salt fast reactor.
SERPENT (version 2.1.29) modelled the neutronic behaviour of the molten salt fast reactor using the Monte Carlo method.
Both Code_Saturne and DYN3D-MG were coupled to one another in 3-D simulations of the reactor. The coupling procedures were implemented with the Multiscale Universal Interface, MUI (https://github.com/MxUI/MUI).
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The project was funded by the following grants:
- EPSRC through the Feasibility Study in Energy Research scheme (Ref: EP/R001618/1)
Additional support was obtained from the following grants:
- EPSRC EP/N016602/1 and EP/N033841/1
- Future Emerging Technologies funding scheme of the European Union’s Horizon 2020 research and innovation programme under grant agreement No 671564
- EPSRC RAP-Tier 2 allocation provided access to the CIRRUS clusterEP/R001618/1 from Feasibility Study in Energy Research scheme
Additional Support from:
- EPSRC EP/N016602/1 and EP/N033841/1
- Future Emerging Technologies funding scheme of the European Union’s Horizon 2020 research and innovation programme under grant agreement No 671564
- EPSRC RAP-Tier 2 allocation provided access to the CIRRUS cluste
The all-British Marendaz Special the man, the cars and the aeroplanes
No full textThis is the story of Captain Marendaz, a pilot in the RFC in the Great War and his life as a manufacturer of cars in the 1920s and 1930s when he competed extensively at Brooklands and elsewhere, before moving on to designing and building aircraft. He was closely associated with Stirling Moss's parents and Kaye Don, being involved in trialling and record-breaking with his own cars and the American Graham-Paige. His passage through life was not smooth, being frequently coloured by disputes, ending up with him being arrested under the notorious Category 18B regulations in 1940, causing him to move to South Africa after the war, where trouble followed him before his return to England in 1972. The book also contains a considerable number of first-hand accounts, by people who worked for Captain Marendaz, of life in a small car and aircraft factory before the war, giving a revealing insight into the social history of the period. His sports cars are attractive with good lines, a point brought out in the many illustrations taken in period and more recently of survivors. His correspondence with the author and others provides an insight into his controversial lif
Turbulent Flow data as PyTorch tensors for ML: Kolmogorov Flow at Re=222, and Kelvin-Helmholtz instability
No full textThis dataset contains three files, listed below. The Kolmogorov flow is generated using a spectral solver, available at: https://github.com/google/jax-cfd. The Kelvin-Helmholtz Instability is generated using an in-house code. Case 1: Kolmogorov Flow nu_0p0045_2500_8f_uv_128.pt -- a PyTorch tensor containing 2500 eight-frame videos of a 2D Re=222 forced turbulent flow (Kolmogorov flow), with only velocity vectors provided. The first 2000 samples are used as training data, the next 450 are used for validation and the final 50 are used to test the model, after training. Case 2: Kelvin Helmholtz InstabilityTraining and Validation:kh_8f_72_208_r34568.pt -- a PyTorch tensor containing 1000 eight-frame videos of a Kelvin-Helmholtz instability flow from 5 realisations of the flow (i.e. initialised from different random seeds). Each two hundred videos are from one simulation - the last two hundred may be used as a validation set. Testing: kh_8f_72_208_r9.pt -- a PyTorch tensor containing 200 eight-frame videos of a Kelvin-Helmholtz instability flow from a realisation of the flow different to the above. This is used as the test set for a model trained on kh_8f_72_208_r34568.pt
Vortex dynamics in an electrically conductive fluid during a dipole-wall collision in presence of a magnetic field
No full textWe investigate numerically the flow physics generated by the collision of a vortex against a wall in an electrically conductive fluid. Governing magnetohydrodynamic equations are solved by the lattice Boltzmann method. Our findings demonstrate that the presence of a magnetic field modifies significantly the vortex dynamics. Specifically, it exerts a braking effect on the vortex that increases with the magnetic Prandtl number. Our results are linked to the transfer of energy between the velocity and the magnetic fields, as well as to the evolution of their enstrophies
Multi-fidelity Surrogate Modelling of Wall Mounted Cubes
No full textThis paper focuses on the application of multi-fidelity surrogate modelling to characteristics of a flow as it changes with a parameter. This provides insight into the potential of combining multi-fidelity modelling approaches with varying fidelities of computational fluid dynamics methods to a parameter space exploration. A limited number of trusted high-fidelity large eddy simulation data points, in combination with an extended study using lower-fidelity Reynolds averaged Navier–Stokes modelling is used as the input for the surrogate model. Multi-fidelity surrogate models are implemented to bridge the low-fidelity and high-fidelity models providing an improved surrogate model over using a single fidelity alone. The flow around tandem wall mounted cubes at varying inlet yaw angle is used as an aerodynamic test case for this methodology. Results presented show that the multi-fidelity surrogate modelling provides a significant improvement over single fidelity modelling for the prediction of global flow properties. This methodology is then extended to combine multiple local flow features into the multi-fidelity model to build up fuller descriptions of the flow at angles not included in the training data for the model. The results of this are presented for both one-dimensional line plots at a range of locations along the center line of the flow and for two-dimensional slices of the velocity field. The multi-fidelity surrogate model produces results at locations in the parameter space away from the high fidelity training data that match closely to large eddy simulation results.</p
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