ARCHER » ARCHER Image and Video Competition 2019 Gallery

ARCHER Image and Video Competition 2019 Gallery

1. The chain-melted phase now understood from simulating potassium. Chains can be seen flowing through the host-guest structure.

1. The chain-melted phase now understood from simulating potassium. Chains can be seen flowing through the host-guest structure.

Victor Naden Robinson, The University of Edniburgh, Physics and Astronomy

Some elements form a host-guest structure with 1D chains under compression, and when heated these chains can "melt". Here we attempted to simulate this phenomenon to understand the nature of this order-disorder transition. Starting from ab initio methods we developed a force field in order to simulate a large number of chains and map out the correlation between different chains and along individual chains, revealing the full 3D nature of the order-disorder transition.

2. Electron localization function (ELF) 001 cuts through hot dense liquid lithium.

2. Electron localization function (ELF) 001 cuts through hot dense liquid lithium.

Victor Naden Robinson, The University of Edniburgh, Physics and Astronomy

100 cuts through high pressure and temperature liquid lithium showing the electron localization function (ELF) isosurface from 0.0 (blue) to 1.0 (red). Off site charge density appears to localize between atoms with no nuclei in their centre.

3. Simulating disk galaxies inside a cosmological volume

3. Simulating disk galaxies inside a cosmological volume

Dr. Weiguang Cui, IFA, University of Edinburgh

This movie shows a simulated disk galaxy which is similar to our milk way galaxy in both mass and size. The purple-red color map shows the smoothed gas distribution in side the galaxy, while the white dots represent each simulated star particles. The researcher, with their collaborator, run a very high-resolution simulation in Archer to search for disk-like galaxies and to understand their formation within a cosmological content. This simulation includes a very complex model which mimic the most baryon processes happened in the Universe. The movie shows an example of the typical disk-like galaxy formed in the simulation. The team is working right now on understanding its formation through looking back to its complete history.

4. Store Glacier calving in response to melt undercutting

4. Store Glacier calving in response to melt undercutting

Dr Joe Todd, Geography & Sustainable Development, University of St Andrews

The release of icebergs from glaciers which flow into the ocean ("calving"), is a process which is highly sensitive to climate change, and a possible major contributor to future sea level rise. We use the "HiDEM" model, which represents glaciers as connected ice blocks, to simulate how iceberg calving is affected by climate processes. This animation shows an underwater view of the response of Store Glacier, west Greenland, to undercutting of the glacier front by warm ocean water. This warm water melts glacier ice, with fastest melt rates at the base. This melt undercutting destabilises the glacier and promotes iceberg calving. This is a major source of ice loss from the Greenland Ice Sheet. At the front, Store Glacier is half a kilometre thick, and each cube of ice in this animation contains enough ice to fill 3 Olympic-size swimming pools.

5. Turbulence-resolving simulations of a utility-scale offshore wind farm, highlighting the flow structures and turbulence of turbine wakes

5. Turbulence-resolving simulations of a utility-scale offshore wind farm, highlighting the flow structures and turbulence of turbine wakes

Dr Georgios Deskos, Imperial College London
* * * Winning Early Career Researcher entry * * *

Coherent (vortical) structures of utility-scale offshore wind turbine wakes, interacting with each other and the ambient atmospheric turbulence.The present simulation was performed on ARCHER using the high-fidelity, high scalability wind farm simulator, WInc3D. The wind turbines are modelled using an enhanced actuator line model. Photos are not enhanced.

6. Cavitation bubble collapse

6. Cavitation bubble collapse

Mr Duncan Dockar, University of Edinburgh, School of Engineering

Cavitation is the phenomenon where a bubble can spontaneously form within a liquid due to a local reduction in pressure. When these cavitation bubbles collapse, they release a high-speed liquid jet which can result in pitting of the nearby solid surface. This can be a major problem where the repeated formation and collapse of cavitation bubbles over many thousands of cycles can cause significant structural damage, particularly in turbomachinery. However, at the nano- to micro-scale there are potentially beneficial applications for cavitation, such as the cleaning of high-precision micro-electronic sensors. Our Molecular Dynamics (MD) simulation shows the jet formed from a collapsing cavitation bubble subjected to a shock wave, and the resulting damage to the nearby silicon substrate. We hope this research will further understanding of how pitting occurs in solids, and the conditions to reduce the effects of cavitation erosion.

7. Stereoscopic visualisation of vortex structures showing Q-criterion surfaces coloured by vorticity. Strong pressure gradients are indicated by black regions.

7. Stereoscopic visualisation of vortex structures showing Q-criterion surfaces coloured by vorticity. Strong pressure gradients are indicated by black regions.

Dr Markus Zauner, University of Southampton, AFM Group

Laminar-flow profiles aim to maintain laminar boundary layers for a large part of the airfoil to increase the aerodynamic performance of next-generation aircraft wings. At typical speeds of modern airplanes around 85% of the speed of sound, supersonic regions occur over wings. It is of great interest to study the interaction of shock waves with the wall-bounded flow, as this can lead to severe flow separation or undesirable phenomena like wing buffeting. Direct numerical simulations were carried out using more than five billion grid points resolving even small turbulent structures. The image above shows the turbulent wake of a wing section at a Reynolds number of half a million, where black regions indicate strong pressure gradients across shock waves or acoustic waves. Stereoscopic visualisations give a great impression of three-dimensional vortex structures using simple red/blue 3D glasses.

8. Hydrogen partitioning during Earth's core-mantle differentiation

8. Hydrogen partitioning during Earth's core-mantle differentiation

Dr Li Yunguo, University College London

The ab initio molecular dynamics trajectories of hydrogen shows that most hydrogen atoms will be partitioned into the core materials at conditions simulating the Earth's core-mantle differentiation process. This simulation clearly demonstrates the siderophile ("iron-loving") nature of hydrogen, and implies that the Earth's core can be a reservoir of hydrogen.

9. Hydrogen partitioning during Earth's core-mantle differentiation

9. Hydrogen partitioning during Earth's core-mantle differentiation

Dr Li Yunguo, University College London

The ab initio molecular dynamics trajectories shows that most hydrogen atoms (white balls) stay in the core material (liquid Fe), while few go into the mantle material (silicate melt) at conditions simulating the Earth's core-mantle differentiation process. This simulation clearly demonstrates the siderophile ("iron-loving") nature of hydrogen, and implies that the Earth's core can be a reservoir of hydrogen.

10. Artistic representation of an angle-resolved photoemission spectroscopy experiment

10. Artistic representation of an angle-resolved photoemission spectroscopy experiment

Mr Nelson Yeung, University of Warwick, Physics Department

An experiment that measures the energy and momentum of electrons in tungsten diselenide. The gold coloured rods and blocks are electrodes made from platinum, which are connected to a power source. The green block is boron nitride, with 3 layers of 2D tungsten diselenide sitting on top of it. The grey atoms at the top are graphene, which is in contact with the electrode. This setup is essentially a capacitor which gives rise to the accumulation of charge in an area of the tungsten diselenide when a voltage is applied to the electrodes. A focused ultraviolet beam is fired at the tungsten diselenide which causes electrons (red balls) to eject from it. The energy and momentum of the ejected electrons are then measured. Computer simulations were used to simulate the results of this experiment.

11. Tunnels throughout the extracellular domain of Patched1

11. Tunnels throughout the extracellular domain of Patched1

T. Bertie Ansell, Oxford University

The Patched1 receptor is a key tumour suppressor membrane protein in the Hedgehog signalling pathway. Recent structural and biochemical studies suggest Patched1 may function as a putative sterol transporter in order to inhibit the Class F G-protein coupled receptor Smoothened. Atomistic molecular dynamics simulations of the Patched1 extracellular domain, bound to a cholesterol molecule, were performed under ARCHER HecBioSim allocated computational time. These simulations were used to assess formation of dynamic tunnels throughout the extracellular domain which we demonstrated collapse upon binding of Sonic Hedgehog ligand cholesterol attachment (Rudolf et al. 2019, Nat. Chem. Biol). The image shows an overlay of Patched1 extracellular domaintunnels on the full length Patched1 protein. We identify tunnels which egress proximal to the membrane region and through two novel side portals. Tunnels are shown as midpoint through the tunnel and coloured by tunnel cluster.

12. Interaction between bubbles and turbulence in pool boiling system

12. Interaction between bubbles and turbulence in pool boiling system

Linlin Fei and Kai H. Luo, Department of Mechanical Engineering, University College London

This image shows 3D high-resolution direct numerical simulations of pool boiling process using an advanced cascaded Lattice Boltzmann method. The bubbles are in green and the high temperature regions are marked in red color. Multi-scale phenomena and turbulence fluctuations can be clearly seen from perspectives of the bubble size distributions and the bubble location distributions, respectively. The high-temperature regions dragged by the rising bubbles indicate the enhanced heat-transfer due to the existence of phase-change.

13. Non-continuum gas flow in tight sandstone

13. Non-continuum gas flow in tight sandstone

Dr Lianhua Zhu, Department of Mechanical and Aerospace Engineering, University of Strathclyde

Gas flows in the tight sandstone and shale are non-continuum in nature. The conventional pore-scale computational fluid dynamics methods fail to describe such flows and we need resort to a statistic description, by tracking the probabilities of finding a gas molecular flying with a specific velocity at a specific location. Because there are so many possible velocities and locations, we need a supercomputer like ARCHER to solve the underling equation. This image shows the one of the simulation results obtained with a massively parallel simulator we developed and optimized on ARCHER. With over 20,000 CPU cores, the simulator took only 5 minutes on ARCHER to get the solution.

14. Turbulent structures and coolant mixing downstream of a single-row of cooling holes

14. Turbulent structures and coolant mixing downstream of a single-row of cooling holes

Christopher Ellis, Loughborough University, Aeronautical and Automotive Engineering

The image presents the Large Eddy Simulation solution of complex turbulent mixing of coolant downstream of a single-row of cooling holes. Turbulent structures are coloured by cooling effectiveness and the centreline plane displays the turbulent velocity field. Simulation results are produced using OpenFOAM, an open source Computational Fluid Dynamics package. A total of 80 million cells are used to resolve the turbulent flow. The present simulation is used to provide accurate results of the surface coolant spread for combustor liner applications and to improve the accuracy of low fidelity methodologies to provide cheap and efficient cooling solutions.

15. Development and interaction of turbulent structures downstream of a single-row of cooling holes

15. Development and interaction of turbulent structures downstream of a single-row of cooling holes

Christopher Ellis, Loughborough University, Aeronautical and Automotive Engineering

The video presents the Large Eddy Simulation solution of complex turbulent mixing of coolant downstream of a single-row of cooling holes. Development and interaction of the coolant flow with the mainstream can be seen as the flow convects downstream. Turbulent structures are coloured by the temperature of the fluid showing the mixing between the 300K mainstream flow and 150K coolant flow. Simulation results are produced using OpenFOAM, an open-source Computational Fluid Dynamics package. A total of 21 million cells are used to resolve the turbulent flow. The present simulation is used to provide accurate results of the surface coolant spread for combustor liner applications and to improve the accuracy of low fidelity methodologies to provide cheap and efficient cooling solutions.

16. Laser wakefield acceleration of an externally injected electron beam.

16. Laser wakefield acceleration of an externally injected electron beam.

Dr Elisabetta Boella, Lancaster University, Physics Department

As a boat travelling in the sea excites in its wake a trail of waves, so does an intense laser when shone into a tenuous plasma. As a surfer can catch these waves and ride them, so do electrons, which in this way get accelerated to high energies. The picture shows the wave (blue) excited by a terawatt laser (colour) propagating through a plasma. An electron beam (witness bunch, red) has been externally injected into the wake. The witness beam is successfully trapped and further accelerated. The simulation, performed with the Particle-In-Cell code OSIRIS on ARCHER, uses laser and beam conditions available at the Cockcroft Institute (Daresbury Laboratory). This work is preparatory to experiments aiming to demonstrate high-quality electrons from laser wakefield via external injection.

17. Passive scalar intensity slice extracted from a three-dimensional fluid flow field of a temporal jet