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: Fakher Assaad, Lehrstuhl für Theoretische Physik I, Julius-Maximilian-Universität Würzburg

HPC Platform used: SuperMUC and SuperMUC-NG of LRZ

Local Project ID: pr94vu

To unravel the complexity of the solid state, researchers from the University of Würzburg have mastered very different and complementary methods. Density functional theory in the local density approximation with added dynamical local interactions using the dynamical mean-field approximation has the merit of being material dependent since one can include the chemical constituents of materials. Spacial and temporal fluctuations are crucial to understand e.g. the Iridates, a topic that is explored with the new pseudo-fermion functional renormalization group. Another aspect of this research are realistic quantum Monte Carlo simulations of free standing graphene aiming to elucidate the role of electronic correlations.

Computational and Scientific Engineering

Principal Investigator: Franco Magagnato, Institute of Fluid Mechanics, Karlsruhe Institute of Technology

HPC Platform used: Hazel Hen and Hawk of HLRS

Local Project ID: Imp_DNS

The heat transfer in the stagnation region of an impinging jet at given jet to distance ratio, Re-number and Temperature ratio also depend on the turbulent inflow characteristics. Using Direct Numerical Simulations, the Nusselt-number distribution as well as the turbulent statistics close to the heated wall have been investigated. At first a calculation has been done comparing the results with published DNS and experiments from Dairay et al. (2015). Since in their paper not all necessary turbulence values were given, the missing values (e.g. turbulent length scale) had to be adjusted in order to fit their results. A good agreement has been found of our calculations with their DNS and experiments.

Astrophysics

Principal Investigator: Luciano Rezzolla, Institute for Theoretical Physics, Goethe University FIAS – Frankfurt Institute for Advanced Studies

HPC Platform used: SuperMUC and SuperMUC-NG

Local Project ID: pr27ju

Two major events are responsible for what is considered the “golden age” of relativistic astrophysics. One is the detection of gravitational waves from merging neutron stars heralding the beginning of the multimessenger age. The other is the effort of the Event Horizon Telescope collaboration culminating in the first image of a black hole. Both events have been aided by simulations that require HPC. With this project, several studies could be conducted well alligned with these type of simulations expanding our knowledge about these important astrophysical events.

Computational and Scientific Engineering

Principal Investigator: Claus-Dieter Munz, Institute of Aerodynamics and Gas Dynamics, University of Stuttgart

HPC Platform used: Hazel Hen and Hawk of HLRS

Local Project ID: hpcmphas

In order to simulate compressible multi-phase flows at extreme ambient conditions, researchers from the Institute of Aerodynamics and Gas Dynamics have developed a multi-phase flow solver based on the discontinuous Galerkin spectral element method in conjunction with an efficient tabulation technique for highly accurate equations of state. The aim of this development is the simulation of phase transition, droplet dynamics and large-scale multi-component phenomena at pressures and temperatures near the critical point. Simulations of liquid fuel injections and shock-drop interactions have been performed on the HPC systems installed at the High-Performance Computing Center Stuttgart (HLRS).

Elementary Particle Physics

Principal Investigator: Hartmut Wittig, Institute for Nuclear Physics and PRISMA Cluster of Excellence, Johannes Gutenberg University of Mainz

HPC Platform used: Hazel Hen and HAWK of HLRS

Local Project ID: GCS-HQCD

The Standard Model of Particle Physics is a highly successful theoretical framework for the treatment of fundamental interactions, but fails to explain phenomena such as dark matter or the abundance of matter over antimatter. Precision observables, such as the anomalous magnetic moment of the muon, aμ, play a central role in the search for “New Physics”. A promising hint is provided by the persistent tension of 3.7 standard deviations between the theoretical estimate for aμ and its experimental determination. In our project we employ the methodology of lattice QCD to compute the hadronic contributions to aμ from first principles. In the long run, our results will supersede the estimates based on data-driven approaches and hadronic models.

Computational and Scientific Engineering

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

HPC Platform used: Hazel Hen and Hawk of HLRS

Local Project ID: DGDES

The aerodynamic flow field around helicopters is challenging to simulate due to complex configurations in relative motion. In an effort to evolve computational fluid dynamics (CFD) technology to new levels of accuracy, reliability, and parallelization efficiency, the helicopter & aeroacoustics group at the IAG of University of Stuttgart employs advanced, high-order Discontinuous Galerkin (DG) methods to help solve difficult rotorcraft-based engineering applications. Complex geometries, curved surfaces, relative motion with elaborate kinematics, and fluid-structure coupling to blade dynamics call for sophisticated techniques within the simulation tool chain to account for all important physical phenomena relevant to the field of study.

Environment and Energy

Principal Investigator: Stefan Emeis , Institute for Meteorology and Climate, Atmospheric Environmental Research, Karlsruhe Institute of Technology

HPC Platform used: SuperMUC and SuperMUC-NG of LRZ

Local Project ID: pr27po

To avoid dangerous climate change, we have to reduce the emission of greenhouse gases radically. This requires – among other measures – an increase of renewable sources of energy like solar and wind. In 2019, already a quarter of Germanys electricity demand has been met by wind power. In order to increase this share, one has to develop sites in hilly terrain. High resolution models are required to assess the suitability of candidate sites with respect to turbulence intensity, power production and variability. This project supports the development of the test-site WINSENT, which is located on the Swabian Alp near Stuttgart.

Materials Sciences and Chemistry

Principal Investigator: Jakob Timmermann, Chair of Theoretical Chemistry, Technical University of Munich

HPC Platform used: SuperMUC and SuperMUC-NG of LRZ

Local Project ID: pr53qu

The water electrolysis in Proton Exchange Membrane (PEM) cells is fitting plenty of industrial requirements. The main drawback of PEM cells however is the overpotential of the oxygen evolution reaction. In its acidic environment iridium dioxide (IrO2) is currently the only stable catalyst. Yet the low abundance of iridium makes a reduction of its loading inevitable. One approach to decrease the catalyst loading is the use of nanoparticles. For catalyst optimization a general understanding of shape and surface structure of these nanoparticles is required. In this project a protocol has been developed to generate and simulate IrO2 nanoparticles based on energies of slab models and to provide insights regarding stability and structure.

Astrophysics

Principal Investigator: Tim Dietrich, University of Potsdam, Dutch National Institut for Subatomic Physics Amsterdam

HPC Platform used: SuperMUC and SuperMUC-NG of LRZ

Local Project ID: pr48pu

Neutron stars are ultracompact stars in which densities above the nuclear saturation densities are reached and that provide one of the best laboratories to test nuclear physics principles. Within this project, researchers perform 3+1-dimensional numerical-relativity simulations studying the last few orbits before the merger of two of these stars. In fact, a binary neutron star merger is one of the most energetic phenomena in our Universe and is accompanied by a variety of electromagnetic signatures and with characteristic gravitational-wave signatures. With the help of these simulations existing theoretical models can be developed and verified and the growing field of multi-messenger astronomy is supported. 

Computational and Scientific Engineering

Principal Investigator: Harald Klimach, Simulation Techniques and Scientific Computing, University of Siegen

HPC Platform used: SuperMUC of LRZ

Local Project ID: pr62cu

This project looked into various strategies to couple domains of distinct physical and numerical properties to tackle direct aero-acoustic simulations. A turbulent flow around an airfoil and the emitted sound waves in a large area of interest was simulated. Different physical effects can be observed in spatially separated domains and the appropriate equation systems are solved in each one using the best fitting numerical discretization. The main focus of the project was the evaluation of different coupling methods to enable this partitioned simulation on massively parallel systems.

Materials Sciences and Chemistry

Principal Investigator: Johannes Ehrmaier, Department of Theoretical Chemistry, Technical University of Munich

HPC Platform used: SuperMUC of LRZ

Local Project ID: pr53wo

Carbon nitride materials have attracted vast interest in the field of photocatalytic water splitting. However, the underlying mechanism is not fully understood. Herein, results are being reported from large-scale first-principles simulations for the specific electron- and proton-transfer processes in the photochemical oxidation of liquid water with heptazine-based photocatalysts. The results reveal that heptazine possesses energy levels that are suitable for the water oxidation reaction. Moreover, the critical role of the solvent in the overall water-splitting cycle is shown. A simple model is developed to describe the water oxidation mechanism.

Life Sciences

Principal Investigator: Frauke Gräter, Interdisciplinary Center for Scientific Computing, Heidelberg University; and Group for Molecular Biomechanics, Heidelberg Institute for Theoretical Studies

HPC Platform used: JUWELS of JSC

Local Project ID: chhd33

Cells communicate with each other through biochemical as well as mechanical signals. Essential biological processes such as cell division are critically steered by the tension across the cell-cell contacts. Using extensive molecular dynamics simulations, scientists analyzed the underlying molecular principles of mechano-sensing at cell-cell contacts. These simulations can give first insights into how proteins present at the cell-cell contact change their structure and localization and thereby help to sense mechanical stimuli. The findings can help understanding the mechanisms by which tissues, e.g. skin, grow along the direction of pulling forces which were applied by adding virtual springs into the simulation system.

Elementary Particle Physics

Principal Investigator: Ferdinand Evers, Institute of Theoretical Physics, University of Regensburg

HPC Platform used: SuperMUC of LRZ

Local Project ID: pr53lu

The general interest of the researchers of this project is in disordered thin film superconductors within the Boguliubov-deGennes (BdG) theory of the attractive-U Hubbard model in the presence of on-site disorder; the sc-fields are the particle density n(r) and the gap function ∆(r). For this case, system sizes unprecedented in earlier work are being reached. They allow to study phenomena emerging at scales substantially larger than the lattice constant, such as the interplay of multifractality and interactions, or the formation of superconducting islands. For example, it is being observed that the coherence length exhibits a nonmonotonic behavior with increasing disorder strength already at moderate interaction strength.

Elementary Particle Physics

Principal Investigator: Frithjof Karsch, Universität Bielefeld, Faculty of Physics

HPC Platform used: JUWELS and JUQUEEN of JSC

Local Project ID: chbi08

Using the vast computing power of the HPC system JUWELS of JSC, an international team of physicists – the HotQCD Collaboration – simulates almost massless quarks and reveals another piece in the puzzle of how hot quarks and gluons behave under extreme thermal conditions.

Elementary Particle Physics

Principal Investigator: Bin Liu, Hartmut Ruhl, Ludwig-Maximilians-Universität München, Faculty of Physics, Chair for Computational and Plasma Physics

HPC Platform used: SuperMUC of LRZ

Local Project ID: pr92na

High-energy ion-beam therapy of tumours has many advantages compared with conventional radiation therapy. Ion beams generated by synchrotron accelerators have been used in many medical institutions. However, a synchrotron accelerator has a large footprint (soccer field size) and is expensive. With the rapid development of high power laser technology, a laser-plasma ion accelerator is a more compact (table-size) and inexpensive alternative. Ion wave breaking acceleration which happens in laser-driven foam-like plasma targets is a promising regime for designing controllable high-energy high-quality ion accelerators. To gain a deeper knowledge on it, researchers carried out 3D simulations on SuperMUC using the Plasma-Simulation-Code (PSC).

Life Sciences

Principal Investigator: Timothy Clark, Friedrich-Alexander-Universität Erlangen-Nürnberg, Computer-Chemie-Centrum and Interdisciplinary Center for Molecular Materials

HPC Platform used: SuperMUC, SuperMUC-NG

Local Project ID: pr74su

The approximately 800 G-protein coupled receptors (GPCRs) in the human genome regulate communication across cell walls. They are targeted by approximately 40% of all marketed drugs. The project uses molecular-dynamics (MD) simulations to investigate ligand binding and receptor activation processes in GPCRs. An activation index for Class A GPCRs has been developed from a series of µsec molecular-dynamics simulations and tested for 275 published X-ray structures.  Binding of the α-domain of G proteins to GPCRs has also been characterized in detail. Metadynamics simulations in conjunction with unbiased MD simulations demonstrated the effect of mutations on the GPCR-ligand interaction in the histamine H1 receptor.

Materials Sciences and Chemistry

Principal Investigator: Prof. Dr. Lars Pastewka, IMTEK – Department of Microsystems Engineering, University of Freiburg

HPC Platform used: JUQUEEN and JUWELS of JSC

Local Project ID: chka18

Roughness of many natural and engineered surfaces follows a scaling law called self-affine scaling. In project chka18, the origins of self-affine have been investigated using Molecular Dynamics simulations. It was shown that the self-affine roughness emerges naturally during deformation of initially flat surfaces in different materials.

Environment and Energy

Principal Investigator: Hans-Stefan Bauer, Institute of Physics and Meteorology, University of Hohenheim

HPC Platform used: Hazel Hen of HLRS

Local Project ID: WRFSCALE

Numerical models are excellent tools to improve our understanding of atmospheric processes across scales since they provide a consistent 4D representation of the atmosphere. Project WRFSCALE consists of different sub-projects, applying the Weather Research and Forecasting (WRF) model at resolutions between 3 km and 100 m, performing investigations in the fields of data assimilation, bio-geoengineering and boundary layer research. By increasing the resolution to 100 m, the model starts to explicitly resolve the representation of turbulence. With such simulations and comparisons to high-resolution observations, it is the aim to better understand the turbulent boundary layer and its interaction with the underlying land surface.

Environment and Energy

Principal Investigator: Carsten Eden, Institut für Meereskunde, Universität Hamburg

HPC Platform used: JUQUEEN of JSC

Local Project ID: chhh28

The Atlantic Meridional Overturning Circulation transports warm tropical surface water towards northern Europe and returns cold water at depth to the world’s ocean. At the same time it plays a significant role in the global carbon cycle through the ocean’s ability to dissolve carbon dioxide. This overturning is thus of great climatic importance, but a complete picture of its driving forces has not yet emerged due to several observational and theoretical challenges. Using realistic coarse and high resolution ocean models, scientists investigated the ocean response to changes in wind stress and the ability of meso-scale eddy parameterisations to simulate that response.

Computational and Scientific Engineering

Principal Investigator: Andrea Beck(1), Claus-Dieter Munz(1), Christian Rohde(2), (1) Institute of Aerodynamics and Gas Dynamics, University of Stuttgart, (2) Institute of Applied Analysis and Numerical Simulation, University of Stuttgart

HPC Platform used: Hazel Hen of HLRS

Local Project ID: SEAL

In order to quantify the uncertainty due to stochastic input in computer fluid dynamic simulations, researchers from the Institute of Aerodynamics and Gas Dynamics developed an Uncertainty Quantification framework and applied it to direct noise computations of aeroacoustic cavity flows. Simulations have been performed with the discontinuous Galerkin spectral element method on HPC system Hazel Hen at the High Performance Computing Center Stuttgart (HLRS). The aim of this investigation is to gain insight into the sensitivity of uncertain input with respect to the acoustic results and to get a reliable comparison between numerical and experimental results.

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