Latest Results Gauss Centre for Supercomputing e.V.

LATEST RESEARCH RESULTS

Find out about the latest simulation projects run on the GCS supercomputers. For a complete overview of research projects, sorted by scientific fields, please choose from the list in the right column.

Materials Sciences and Chemistry

Principal Investigator: Eunsang Lee, Institute for Physics, Martin-Luther University Halle-Wittenberg

HPC Platform used: JUWELS of JSC

Local Project ID: chhw05

A supramolecular polymer (SMP) has functional groups which interact with each other to form a physical bond. In contrast to chemical bonds, the bond formation in an SMP is reversible and the resulting aggregate morphology in a SMP melt thermally fluctuates. For functional groups allowing only a pairwise association, a ring aggregate is highly important as a ring topologically reduces the mobility of surrounding linear polymers by threading. Using molecular dynamics simulations of SMPs, the effect of ring aggregates on the system relaxation time governing rheological response was investigated. It was shown that the presence of ring aggregates slows down rheological response as measured by a reduction of the so-called entanglement length.

Life Sciences

Principal Investigator: Ville R. I. Kaila, Department of Chemistry, Technical University of Munich (Germany)

HPC Platform used: SuperMUC and SuperMUC-NG of LRZ

Local Project ID: pr53po

Heat shock protein 90 (Hsp90) is a molecular chaperone essential for the folding and stabilization of a wide variety of client proteins in eukaryotes. Many of these processes are associated with cancer and other diseases, making Hsp90 an attractive drug target. Hsp90 is a highly flexible protein that can adopt a wide range of distinct conformational states, which in turn are tightly coupled to the enzyme’s ATPase activity. In this project, atomistic molecular dynamics simulations, free energy calculations, and hybrid quantum mechanics/classical mechanics simulations were performed on both monomeric and full-length dimeric Hsp90 models to probe how long-range effects in the global Hsp90 structure regulate ATP-binding and hydrolysis.

Elementary Particle Physics

Principal Investigator: Andreas Schäfer, Institute for Theoretical Physics, Regensburg University

HPC Platform used: SuperMUC and SuperMUC-NG of LRZ

Local Project ID: pn56yo

The nucleon has an extremely complicated many-body wave function because QCD is very strongly coupled, very non-linear and characterized by massive quantum fluctuations. Its investigation started with collinear processes and has by now progressed to non-collinear ones. The latter are characterized by non-trivial parallel transport, leading to observable effects. Many of these are described by TMDs the properties of which are not yet well understood and are planned to be studied at the new Electron Ion Collider. We have calculated one of the most important of these properties on the lattice. Only in 2020, first lattice calculations, all using alternative approaches, of this quantity were published. All results agree within error.

Environment and Energy

Principal Investigator: Ronald Cohen, Ludwig Maximilians Universität München

HPC Platform used: SuperMUC and SuperMUC-NG of LRZ

Local Project ID: pr92ma

The SuperMUC-NG is being used to simulate materials from first-principles, materials ranging from active materials important to technology to planetary materials that govern, for example, Earth’s magnetic field. Solid and liquid iron at conditions of Earth’s core have been simulated, and transport properties such as electrical and thermal conductivity were computed to constrain the properties that govern Earth’s dynamo. At much lower pressures, filled ices, which are believed to form in the interior of water planets such as Titan, and carbon solubility in silicates melts in the mantle of the Earth were studied. Three new class of materials were developed computationally: polar metallocenes, ferroelectric clathrates, and polar oxynitrides.

Computational and Scientific Engineering

Principal Investigator: Christian Hasse, Simulation of reactive Thermo-Fluid Systems, Technical University of Darmstadt

HPC Platform used: SuperMUC and SuperMUC-NG of LRZ

Local Project ID: pr74xi

Using a canonical jet in cross flow (JICF) flame configuration, researchers of TU Darmstadt performed a high-resolution DNS study concerning differential diffusion effects and mixing characteristics during hydrogen combustion. The investigations in the hydrogen JICF configurations were twofold. First, a detailed analysis of the DNS data was to yield a fundamental understanding of mixing characteristics in the JICF configuration and differential diffusion effects. Second, commonly applied tabulated chemistry approaches and their capability of predicting differential diffusion were to be validated against the DNS data. The latter, which is of highly practical interest for a related project, was the final target of this project.

Astrophysics

Principal Investigator: Jörg Büchner, Max-Planck-Institute for Solar System Research, Göttingen

HPC Platform used: SuperMUC and SuperMUC-NG

Local Project ID: pr74vi

The hot and dilute astrophysical plasmas - from Solar to galactic scales - are inherently turbulent. The turbulence determines transport and structure formation in accretion disks, in the interstellar medium, in clusters of galaxies as well as their observable radiation. Due to its routing in microscopic kinetic processes the turbulence of astrophysical plasmas is, however, not well understood, yet. Utilizing state-of-the-art microphysics particle-in-cell codes in this project self-consistent 3D electromagnetic kinetic simulations were performed to simulate the kinetic turbulence inherently linked with two fundamental processes of energy conversion in the Universe – collisionless shock waves and magnetic reconnection.

Elementary Particle Physics

Principal Investigator: Bin Liu, Helmholtz Institute, Jena

HPC Platform used: JUWELS of JSC

Local Project ID: iwba2layer

Generating high energy ions by irradiating an ultra-intense laser pulse on a foil-coated foam-like double-layer plasma target is investigated with the help of particle-in-cell simulations. The foil is ultra-thin so that the incident laser pulse can penetrate through it. The acceleration of ions happens in the foam when the density of the foam is in the laser-induced relativistic-transparent regime. Simulations show that a proton beam with peak energy beyond 150 MeV is generated by using a 16 Joule laser pulse. The laser pulse used in the simulation is already available, and the targets can be prepared with the current technology. This simulation work provides helpful information for the further experiments and related applications.

Environment and Energy

Principal Investigator: Gerd Schädler, Institute for Meteorology and Climate Research, Department Troposphere Research, Karlsruhe Institute of Technology

HPC Platform used: Hazel Hen and Hawk of HLRS

Local Project ID: HRCM

The African Continent will be severely hit by climate change. A necessary building brick for counteraction are reliable projections of the African climate of our century. The CORDEX CORE initiative is designed to provide such information for the CORDEX CORE regions, among them CORDEX CORE Africa. IMK-TRO contributed to this with an ensemble of presently ten regional climate simulations performed on the Hazel Hen at HLRS Stuttgart. Results indicate dramatic changes especially in precipitation. The simulations presented here will be part of the IPCC AR6 atlas of regional climate change and the CORDEX data repository. They will be freely available for impact, adaptation and mitigation studies.

Life Sciences

Principal Investigator: Ville R. I. Kaila, Department of Chemistry, Technical University of Munich (Germany)

HPC Platform used: SuperMUC and SuperMUC-NG of LRZ

Local Project ID: pr27xu

Complex I is the largest and most intricate respiratory enzyme, which couples the free energy released from quinone reduction to transfer protons across a biological membrane. Recent X-ray structures of bacterial and eukaryotic complex I have advanced our understanding of the enzyme’s function, but the mechanism of its long-range energy conversion remains unsolved. Here, we use atomistic molecular dynamics simulations and free energy calculations to study how the protonation state, hydration dynamics, and conformational dynamics of complex I regulate its proton pumping activity. Our simulations mimic transient states in the enzyme’s pumping cycle to draw a molecular picture of the protonation signals along the membrane domain of complex I.

Environment and Energy

Principal Investigator: Mauro Cacace, Helmholtz Centre Potsdam GFZ - German Research Centre for Geosciences

HPC Platform used: JUWELS of JSC

Local Project ID: MOBS

Quantifying the dynamics of basins across diverse time and space scales is one challenge faced by earth scientists. To understand their response to natural or man-made forcing is crucial to constrain the state and fate of georesources and hazards related to their exploitation. In this project, we developed and used a hybrid scalable modelling approach combining deterministic and probabilistic modules to improve our comprehension of the complex nonlinear dynamics of this specific terrestrial compartment interacting with the other geo-hydro-atmosphere systems making up the system Earth.

Computational and Scientific Engineering

Principal Investigator: Dr. Manuel Keßler, Institute of Aerodynamics and Gas Dynamics, University of Stuttgart

HPC Platform used: Hazel Hen and Hawk of HLRS

Local Project ID: GCSHELISIM

The helicopters & aeroacoustics group of the Institute of Aerodynamics and Gas Dynamics at the University of Stuttgart continues to develop their well-established and validated rotorcraft simulation framework. Vibration prediction and noise reduction are currently the focus of research, and progress into manoeuvre flight situations is on the way. For two decades, high-performance computing leverged within the HELISIM project has enabled improvements for conventional helicopters as much as for the upcoming eVTOLs, commonly known as air taxis, in terms of performance, comfort, and efficiency. Community acceptance will be fostered via noise reduction and safety enhancements, made possible by this research project.

Elementary Particle Physics

Principal Investigator: Andreas Schäfer, Institute for Theoretical Physics, Regensburg University

HPC Platform used: SuperMUC and SuperMUC-NG of LRZ

Local Project ID: pn69ma

Lattice QCD enables calculation of many details of quark-gluon bound states like the proton. One first parameterizes all properties of, e.g., the proton by certain parameters and functions. Next, one links experimental observables to these quantities and clarifies their meaning. In recent years, lattice calculations have become a valid alternative to performing experiments to determine these quantities. We have calculated the quantity d2, which characterizes certain spin-dependent effects and is linked to the color force exerted on quarks in a proton or neutron. Non-trivial renormalization properties make this an especially difficult quantity to calculate, but this project was successful in doing so with results that agree with experiment.

Computational and Scientific Engineering

Principal Investigator: Jörg Schumacher, Technische Universität Ilmenau

HPC Platform used: SuperMUC and SuperMUC-NG of LRZ

Local Project ID: pr62se, pn68ni

Turbulent convection is one essential process to transport heat in fluid flows. In many of the astrophysical or technological applications of convection the working fluid is characterized by a very low dimensionless Prandtl number which relates the kinematic viscosity of the fluid to its temperature diffusivity. Two important cases are turbulent convection in the Sun and turbulent heat transfer in the cooling blankets of nuclear fusion reactors. Massively parallel simulations of the simplest setting of a turbulent convection flow, Rayleigh-Bénard convection in a layer or a straight duct that is uniformly heated from below and cooled from above, help to understand the basic heat transfer mechanisms that these applications have in common.

Astrophysics

Principal Investigator: Hans-Thomas Janka, Max Planck Institute for Astrophysics, Garching

HPC Platform used: SuperMUC and SuperMUC-NG of LRZ

Local Project ID: pn69ho, pr53yi

Core-collapse supernovae are among the most energetic events in the Universe and can be as bright as a galaxy. They mark the violent, explosive death of massive stars, whose iron cores collapse to the most exotic compact objects known as neutron stars and black holes. In this project self-consistent 3D simulations with state-of-the-art microphysics were performed for the explosion of a ~19 solar-mass star, whose final 7 minutes of convective oxygen-shell burning had been computed, too. It could be demonstrated that explosions by the neutrino-driven mechanism can produce powerful supernovae with energies, radioactive nickel ejecta, and neutron-star masses and kick velocities in agreement with observations, in particular Supernova 1987A.

Elementary Particle Physics

Principal Investigator: Zoltán Fodor, Bergische Universität Wuppertal

HPC Platform used: JUWELS of JSC

Local Project ID: chwu16

Recent cosmological observations tell us that only a small part of the matter content of the Universe is coming from ordinary particles, e.g. protons and neutrons. We call the rest dark matter. But what constitutes this invisible ingredient of the Universe? A possible candidate is the so called axion, for which a mass limit was worked out in the prequel of this project. To learn more on the features of this hypothetical particle its dynamics was investigated through a link to the strong interactions.

Computational and Scientific Engineering

Principal Investigator: Matthias Meinke, Chair of Fluid Mechanics and Institute of Aerodynamics, RWTH Aachen University

HPC Platform used: Hazel Hen and Hawk of HLRS

Local Project ID: GCS-Aflo

A new active surface actuation technique to reduce the friction drag of turbulent boundary layers is applied to the flow around an aircraft wing section. Through the interaction of the transversal traveling surface wave with the turbulent flow structures, the skin-friction on the surface can be considerably reduced. Highly-resolved large-eddy simulations are conducted to investigate the influence of the surface actuation technique on the turbulent flow field around an airfoil at subsonic flow conditions. The active technique, which previously was only tested in generic scenarios, achieves a considerable decrease of the airfoil drag.

Astrophysics

Principal Investigator: Hans-Thomas Janka, Max Planck Institute for Astrophysics, Garching

HPC Platform used: SuperMUC-NG of LRZ

Local Project ID: pr53yi

Core-collapse supernovae are among the most energetic events in the Universe and can be as bright as a galaxy. They mark the violent, explosive death of massive stars, whose iron cores collapse to the most exotic compact objects known as neutron stars and black holes. In this project self-consistent 3D simulations with state-of-the-art microphysics were performed for the explosion of a ~19 solar-mass star. It could be demonstrated that muon formation in the hot neutron star, which had been ignored in supernova models so far, leads to a faster onset of the explosion. The effects of muons thus over-compensate the delay of the explosion caused by low resolution, where numerical viscosity impedes the growth of hydrodynamic instabilities.

Computational and Scientific Engineering

Principal Investigator: Ulrich Rist, Markus Kloker, Christoph Wenzel, Institute of Aerodynamics and Gas Dynamics, University of Stuttgart

HPC Platform used: Hazel Hen and Hawk of HLRS

Local Project ID: GCS-Lamt

This project explores laminar-turbulent transition, turbulence, and flow control in boundary layers at various flow speeds from the subsonic to the hypersonic regime. The physical problems under investigation deal with prediction of laminar-turbulent transition on airfoils for aircraft, prediction of critical roughness heights in laminar boundary layers, turbulent drag reduction, the origins of turbulent superstructures in turbulent flows, the use of roughness patterns for flow control, effusion cooling in laminar and turbulent supersonic boundary-layer flow, DNS of disturbance receptivity on a swept wing at high Reynolds numbers, and plasma actuator design for active control of disturbances in a swept-wing flow.

Astrophysics

Principal Investigator: Daniel Ceverino, Zentrum für Astronomie, Institut für Theoretische Astrophysik, Universität Heidelberg

HPC Platform used: SuperMUC and SuperMUC-NG of LRZ

Local Project ID: pr92za

The FirstLight project at LRZ is a large database of numerical models of galaxy formation that mimic a galaxy survey of the high-redshift Universe, before and after the Reionization Epoch. This is the largest sample of zoom simulations of galaxy formation with a spatial resolution better than 10 pc. This database improves our understanding of cosmic dawn. It sheds light on the distribution of gas, stars, metals and dust in the first galaxies. This mock survey makes predictions about the galaxy population that will be first observed with future facilities, such as the James Webb Space Telescope and the next generation of large telescopes.

Computational and Scientific Engineering

Principal Investigator: Christian Bauer, Institute of Aerodynamics and Flow Technology, German Aerospace Center (DLR)

HPC Platform used: SuperMUC and SuperMUC-NG of LRZ

Local Project ID: pr62zu

A large amount of the energy needed to push fluids through pipes worldwide is dissipated by viscous turbulence in the vicinity of solid walls. Therefore the study of wall-bounded turbulent flows is not only of theoretical interest but also of practical importance for many engineering applications. In wall-bounded turbulence the energy of the turbulent fluctuations is distributed among different scales. The largest energetic scales are denoted as superstructures or very-large-scale motions (VLSMs). In our project we carry out direct numerical simulations (DNSs) of turbulent pipe flow aiming at the understanding of the energy exchange between VLSMs and the small-scale coherent.