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.

Environment and Energy

Principal Investigator: Cedrick Ansorge, Institute of Geophysics and Meteorology, University of Cologne (Germany)

HPC Platform used: JUQUEEN and JUWELS of JSC

Local Project ID: hku24

A new avenue towards the study of the Planetary Boundary Layer (PBL), namely direct numerical simulation, is pursued in this project. The geophysical problem—characterized by enormous number of degrees of freedom—is condensed to its fluid mechanical core and solved explicitly which does not require assumptions or closures for the turbulent exchange of heat pollutants, heat and momentum: It rather represents the whole cascade of turbulent motion in a miniature problem. For the first time, this allows to quantify and understand surface fluxes without utilization of simplifying assumptions and theories such as Monin—Obukhov Similarity Theory.

Computational and Scientific Engineering

Principal Investigator: Andreas Kempf, Chair for Fluid Dynamics, University of Duisburg-Essen

HPC Platform used: Hazel Hen of HLRS

Local Project ID: GCS-snef

Shock-tube experiments are a classical technique to provide data for reaction mechanisms and thus help to reduce emissions and increase the efficiency of combustion processes. A shock-tube experiment at critical conditions (low temperature), where the ignition occurs far away from the end wall, is simulated. Understanding the mechanism that leads to such a remote ignition is crucial to improve the quality of future experiments.

Computational and Scientific Engineering

Principal Investigator: Thorsten Lutz, Institute of Aerodynamics and Gas Dynamics (IAG), University of Stuttgart (Germany)

HPC Platform used: Hazel Hen of HLRS

Local Project ID: WEAloads

As part of the WindForS project WINSENT two wind turbines and four met masts will be installed in the Swabian Alps in Southern Germany for research proposes. The results of highly resolved numerical simulations of this wind energy test site located in complex terrain are shown. By means of Delayed Detached Eddy Simulations (DDES) the turbulent flow above a forested steep slope is analyzed in order to evaluate the inflow conditions of the planned wind turbine in detail. The complex inflow conditions and production of turbulence due to the shape of the topography and the vegetation are evaluated. The intention of using supercomputers for these applications is to analyze the local atmospheric flow field in as much detail as possible.

Astrophysics

Principal Investigator: Jenny G. Sorce(1), Klaus Dolag(2), (1) Leibniz-Institut für Astrophysik Potsdam/AIP (Germany) and Centre de Recherche Astrophysique de Lyon (France), (2) Universitäts-Sternwarte, Ludwig-Maximilians-Universität München (Germany)

HPC Platform used: SuperMUC

Local Project ID: pr74do

The neighbourhood in the immediate vicinity of the Milky Way is known as the “Local Group”. It is a binary system composed of two averaged sized galaxies (the Milky Way and Andromeda) dominating a volume that is roughly ~7 Mpc in diameter. At a distance of around 15Mpc, the Virgo cluster comes into view as the main defining feature of our neighbourhood on these scales. Beyond Virgo, a number of well known and well observed clusters like Centaurus, Fornax, Hydra, Norma, Perseus and Coma dominate the night sky. This is our cosmic neighbourhood. The goal of this project is, for the first time, to perform targeted, state of the art hydro-dynamical simulations covering this special region of the universe and to compare the results with various...

Astrophysics

Principal Investigator: Felix Spanier(1), Anne Stockem-Novo(2), (1) Karlsruhe Institut für Technologie, Eggenstein-Leopoldshafen (Germany), (2) Ruhr-Universität Bochum (Germany)

HPC Platform used: SuperMUC

Local Project ID: pr74se

Active galactic nuclei (AGN) are powerful emitters of photons in energy ranges from few millielectron volts (meV) to several teraelectron volts (TeV). These sources show variabilities as fast as a few minutes. It is believed that the emission originates from particles accelerated in shock waves in the jet of AGN. Observational data, however, is too sparse to constrain radiation models. Therefore, light curves (i.e. temporal data) are used to constrain models further. Using the Particle-in-Cell method to investigate shock collisions, this project aims at gaining more detailed insight into a special case of variability.

Life Sciences

Principal Investigator: Martin Zacharias, Lehrstuhl für Molekulardynamik, Physik-Department T38, Technische Universität München (Germany)

HPC Platform used: SuperMUC of LRZ

Local Project ID: pr74bi

Small GTPase protein molecules mediate cellular signaling events by transient binding to other proteins that in turn activate or deactivate processes in the cell. The signaling of GTPase proteins is mediated by switching between different active or inactive conformational states. Understanding the molecular details of these switching events is of great importance to understand cellular regulation and to design drug molecules to control cell functions. Using Molecular Dynamics advanced sampling techniques, the mechanism of conformational switching in the Rab8a-GTPase were investigated.

Astrophysics

Principal Investigator: Klaus Dolag, Universitäts-Sternwarte, Ludwig-Maximilians-Universität München (Germany)

HPC Platform used: SuperMUC

Local Project ID: pr83li, pr86re

The outcome of a large set of cosmological, hydro-dynamical simulations from the project Magneticum now became made available to the general community through operating a cosmological simulation web portal. Users are able to access data products extracted from the simulations via a user-friendly web interface, browsing through visualizations of cosmological structures while guided by meta data queries helping to select galaxy clusters and galaxy groups of interest. Several services are available for the users: (I) ClusterInspect; (II) SimCut (raw data access); (III) Smac (2D maps); (IV) Phox (virtual X-ray observations, taking the specifications of various, existing and future X-ray telescopes into account.

Computational and Scientific Engineering

Principal Investigator: Eckart Laurien, Institute of Nuclear Technology and Energy Systems (IKE), University of Stuttgart (Germany)

HPC Platform used: Hazel Hen

Local Project ID: TurboCon3

The accident management in a generic nuclear power plant containment with a convection flow of high-temparature gases is simulated. An activated spray mixes the turbulent flow and inhibits the formation of a possibly explosive upper region filled with hydrogen. Condensation of the steam is promoted and the maximum pressure, which may also endanger the containment integrity, is limited.

Computational and Scientific Engineering

Principal Investigator: Olga Shishkina, Max Planck Institute for Dynamics and Self-Organization, Göttingen (Germany)

HPC Platform used: SuperMUC

Local Project ID: pr84pu, pr92jo

Turbulent thermal convection is ubiquitous in nature and technical applications. Inclined convection, where a fluid is confined between two differently heated parallel surfaces, which are inclined with respect to gravity, is one of the main model systems to study the physics of turbulent thermal convection. In this project, we focus on the investigation of the interaction between shear and buoyancy and want to know, how they influence the development of the flow superstructures and contribute to the mean heat transport enhancement in the system.

Elementary Particle Physics

Principal Investigator: Hinnerk Stüben, Regionales Rechenzentrum, Universität Hamburg (Germany)

HPC Platform used: JUQUEEN

Local Project ID: hhh43

The fundamental constituents of the strong nuclear force are quarks and gluons, which themselves bind together to form the familiar building blocks of nuclear physics, protons and neutrons. The two most common forms of quarks are the up quark and the down quark. The quarks carry electric charges +2/3 (up) and −1/3 (down). A proton is composed of two up quarks and one down quark (it has charge +1), whereas the neutron has two down and one up quark (it is charge-neutral). The understanding of the strong nuclear force has now matured to the level where quantitative statements can be made about the role of electric charges on the quark-gluon structure of matter.

Elementary Particle Physics

Principal Investigator: Rainer Sommer, DESY, Zeuthen (Germany)

HPC Platform used: SuperMUC, JUQUEEN

Local Project ID: pr84mi, hde09

Quarks and gluons form protons and neutrons and thus most of the matter. The strength with which they interact is called the strong coupling. It is one of the fundamental parameters of Nature, but not that well known. Researchers used simulations on a space-time lattices to determine the coupling with good overall precision. The experimental inputs are the masses of pi-mesons and K-mesons as well as their decay rates into leptons (such as electrons), neutrinos and photons. Many simulations and their subsequent analysis were necessary in order to extrapolate to the required space-time continuum in all steps.

Life Sciences

Principal Investigator: Birgit Strodel, Forschungszentrum Jülich (Germany)

HPC Platform used: SuperMUC of LRZ

Local Project ID: pr74da

Amyloid-β (Aβ) peptide oligomers are the major contributing cause of neuronal death in Alzheimer’s disease. To understand how membrane lipids affect Aβ oligomerization, a system that includes six Aβ peptides and a membrane comprised of 1058 lipids was comprised to study these effects using molecular dynamics (MD) simulations. Hamiltonian replica-exchange molecular dynamics HREMD was employed to enhance the configurational sampling afforded by the MD protocol. The aim of this ongoing work is to see how the membrane lipids affect the conformation and morphology of the Aβ oligomers.

Elementary Particle Physics

Principal Investigator: Karl Jansen, Deutsches Elektronen-Synchrotron/DESY, Zeuthen (Germany)

HPC Platform used: JUQUEEN

Local Project ID: hch02

In the project Lattice QCD simulations were carried out to compute the individual contributions of quarks and gluons to the proton spin which the value ½ in nature. The result confirms the experimental data which has been collected during the past 30 years and which indicates that only a small fraction of the proton spin is carried by the intrinsic spin of the quarks.

Elementary Particle Physics

Principal Investigator: Alberto Martinez de la Ossa and Jens Osterhoff, Deutsches Elektronen-Synchrotron, Hamburg (Germany)

HPC Platform used: JUQUEEN

Local Project ID: hhh23

Plasma wakefield accelerators (PWAs) can sustain electric fields on the order of 100 GV/m for the acceleration of electrons up to GeV energies in a cm-scale dis-tance. Harnessing such highly-intense accelerating gradients requires precise con-trol over the process of injection of the electron beams. By means of large-scale simulations, this project explored multiple novel solutions for the generation of high-quality electron beams from a PWA, as required for free-electron lasers (FELs). Using PWAs, it is envisaged that miniaturized and cost effective FELs may be constructed, dramatically increasing the proliferation of this technology with revolutionary consequences for applications in biology, medicine, material science and physics.

Materials Sciences and Chemistry

Principal Investigator: Bernd Meyer, Interdisciplinary Center for Molecular Materials and Computer-Chemistry-Center, Friedrich-Alexander-Universität Erlangen-Nürnberg (Germany)

HPC Platform used: SuperMUC of LRZ

Local Project ID: pr74be

The electronic and optical properties of oxide surfaces and nanoparticles can be tuned by attaching specifically tailored organic molecules. This is employed in molecular electronics or when building dye-sensitized solar cells. Such a chemical functionalization is usually done in solution. In this work, advanced molecular dynamics sampling techniques based on a quantum-chemical description of the atomic interactions are used to obtain a fundamental understanding of the chemical reaction mechanisms at such solid-liquid interfaces. The simulations allow to identify the key reaction intermediates and they provide new insights into the important role of the hydrogen-bond network and the mobility of protons at the interface.

Elementary Particle Physics

Principal Investigator: Nora Brambilla, Physik Department T30f, Technische Universität München (Germany)

HPC Platform used: SuperMUC

Local Project ID: pr48le, pr83pu

Nuclear matter changes at high temperatures from a gas of hadrons into a quark-gluon plasma. For sufficiently high temperatures this quark-gluon plasma can be described in terms of effective field theory calculations assuming weak coupling. We calculate the QCD Equation of State and the free energies of heavy quark systems using Lattice QCD, a Markov Chain Monte Carlo approach for solving the QCD path integral numerically in an imaginary time formalism. By comparing the continuum extrapolated results to weak-coupling calculations in different EFT frameworks, we establish their applicability.

Life Sciences

Principal Investigator: Helmut Grubmüller, Max Planck Institute for Biophysical Chemistry, Göttingen (Germany)

HPC Platform used: SuperMUC of LRZ

Local Project ID: pr62de

The ribosome is a complex molecular machine which plays an essential role in protein biosynthesis across all domains of life. Knowing its structural and mechanistic details may help to develop new medical treatments by controlling protein production or to understand the context of neurodegenerative diseases. Using molecular dynamics simulations this project studies how certain nascent peptides, similar to particular antibiotics, affect the transport of produced polypeptide chains through the exit tunnel rendering this process moreover an attractive target from a pharmacological perspective.

Astrophysics

Principal Investigator: Jenny Sorce, Leibniz-Institut für Astrophysik Potsdam (Germany) and Centre de Recherche Astrophysique de Lyon (France)

HPC Platform used: SuperMUC of LRZ

Local Project ID: pr74je

Galaxy clusters are large reservoirs of galaxies. As such they are perfect objects of studies to unravel the mysteries of galaxy formation and evolution in dense environments. At ~50 million light-years away from Earth, the Virgo cluster, a gathering of more than a thousand galaxies, is our closest cluster-neighbour. Its proximity permits deep observations. Cosmological numerical simulations of the cluster constitute the numerical counterparts to be compared with observations to test our theoretical models. In such simulations, dark matter (nature of most of the matter in the Universe) and baryons (visible matter) follow physical laws to reproduce our closest cluster-neighbour and its galaxies in a simulated box across cosmic time.

Astrophysics

Principal Investigator: Hans-Thomas Janka, Max-Planck-Institut für Astrophysik, Garching (Germany)

HPC Platform used: SuperMUC

Local Project ID: pr53yi

Traditionally, numerical simulations of core-collapse supernovae have been performed with spherically symmetric initial models for the progenitor stars, because stellar evolution is computed with this restriction. Recently, however, it has been demonstrated that pre-collapse asymmetries in the convectively burning oxygen shell can have an impact on the explosion by enhancing turbulence behind the supernova shock. In this project researchers simulated the final seven minutes of oxygen burning and the subsequent collapse of a 19 solar-mass star in order to investigate the consequences of pre-collapse asymmetries for the supernova explosion.

Computational and Scientific Engineering

Principal Investigator: Jonas Wack, Institute of Fluid Mechanics and Hydraulic Machinery, University of Stuttgart (Germany)

HPC Platform used: Hazel Hen of HLRS

Local Project ID: HYPERBOL

In the last decades, hydro power plants have experienced a continual extension of the operating range in order to integrate other renewable energy sources into the electrical grid. When operated at off-design conditions, the turbine experiences cavitation which may reduce the power output and can cause severe damage in the machine. Cavitation simulations are necessary to investigate phenomena like the full load instability. The goal of this project is to understand the physical mechanisms that result in an instability at off-design conditions to identify measures that can avoid the occurrence of instability.