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.

Computational and Scientific Engineering

Principal Investigator: Neil Sandham, Faculty of Engineering and Physical Sciences, University of Southampton (U. K.)

HPC Platform used: Hazel Hen of HLRS

Local Project ID: PP17174149

Shock-related buffeting is a phenomenon that occurs when air passes over the wing of an aeroplane under extreme conditions and can have profound consequences for how wings are engineered and their durability. Leveraging the computing capacities of HPC system Hazel Hen, researchers at the University of Southampton have been investigating this phenomenon using direct numerical simulations.

Computational and Scientific Engineering

Principal Investigator: Qiaoyan Ye and Bo Shen, Fraunhofer Institute for Manufacturing Engineering and Automation, Stuttgart

HPC Platform used: Hazel Hen of HLRS

Local Project ID: PbusRobe

Spray painting is the most common application technique in coating technology. Typical atomizers used in spray coating industries are such as High-speed rotary bell and spray guns with compressed air. High-speed rotary bell atomizers provide an excellent paint film quality as well as high transfer efficiencies (approx. 90%) due to electrostatic support. Small and medium-sized enterprises continue, however, to use compressed air atomizers, although they no longer meet today's requirements from an economic and environmental point of view. It is very important to understand the atomization mechanisms of these two kinds of atomizers, in order to improve the paint quality, to reduce the overspray and to optimize the coating process.

Astrophysics

Principal Investigator: Friedrich Röpke, Zentrum für Astronomie der Universität Heidelberg, Institut für Theoretische Astrophysik und Heidelberger Institut für Theoretische Studien

HPC Platform used: JUQUEEN and JUWELS of JSC

Local Project ID: chwb07

Classical stellar models are formulated in one spatial dimension and parameterize dynamical multidimensional effects. While successful in a qualitative description of how stars evolve, such models lack predictive power. Multidimensional hydrodynamic simulations of critical phases and processes are still extremely challenging but have become feasible due to improved numerical techniques and increasing computational power. This project performs such simulations aiming at an improved understanding of the physics ruling stellar structure and evolution. As an example, a simulation of convective helium-shell burning in a massive star is discussed.

Computational and Scientific Engineering

Principal Investigator: Detlef Lohse, Max-Planck-Institut für Dynamik und Selbstorganisation, Göttingen (Germany), and Max Planck Center Twente for Complex Fluid Dynamics and Physics of Fluids Group, University of Twente (The Netherlands)

HPC Platform used: JUWELS of JSC

Local Project ID: PRA099

Many wall-bounded flows in nature and technology are affected by the surface roughness of the wall. In some cases, this has adverse effects, e.g. drag increase leading to higher fuel costs; in others, it is beneficial for mixing enhancement or transfer properties. Computationally, it is notoriously difficult to simulate these flows because of the vast separation of scales in highly turbulent flows and the challenges involved in handling complex geometries. The studies are carried out in two paradigmatic and complementary systems in turbulence research, Taylor-Couette and Rayleigh-Bénard flow.

Elementary Particle Physics

Principal Investigator: Dr. Stefan Krieg, Forschungszentrum Jülich, Institute for Advanced Simulation, Jülich Supercomputing Centre

HPC Platform used: Hazel Hen of HLRS

Local Project ID: HighPQCD

Nucleons make up more than 99% of the mass of ordinary matter. Computing their properties from first principles, i.e. the theory of Quantum Chromodynamics, is complicated by the non-linear nature of the underlying equations. Only by using supercomputers can we attempt to compute these quantities with the necessary precision. Beyond shedding light on the nature of the nucleons, the results help to resolve some long-standing puzzles in nucleon structure physics and restrict possible models of physics beyond the Standard Model.

Materials Sciences and Chemistry

Principal Investigator: Prof. Dr. Silvana Botti, Friedrich-Schiller-Universität Jena

HPC Platform used: SuperMUC of LRZ

Local Project ID: pr62ja

Direct bandgap silicon can be the key to integrate both electronic and optical functionalities on a silicon platform. Despite considerable effort, achieving light emission from group IV semiconductors has remained unattainable until now. Very recently, ab initio calculations combined with experiments could prove that Ge-rich hexagonal crystal phases of SixGe1-x feature a direct bandgap, tunable in a frequency range coinciding with the low loss window for optical fiber communications. Efficient light emission from direct band gap SiGe could also be shown. Further calculations explore how to engineer light emission by strain and alloying.

Computational and Scientific Engineering

Principal Investigator: Martin Thomas Horsch, Maximilian Kohns, Laboratory of Engineering Thermodynamics, Technische Universität Kaiserslautern

HPC Platform used: SuperMUC of LRZ

Local Project ID: pr48te

Molecular modelling and simulation is an established method for describing and predicting thermodynamic properties of fluids. This project examines interfacial properties of fluids, their contact with solid materials, interfacial fluctuations and finite-size effects, linear transport coefficients in the bulk and at interfaces and surfaces as well as transport processes near and far from equilibrium. These phenomena are investigated by massively-parallel molecular dynamics simulation based on quantitatively reliable classical-mechanical force fields.

Computational and Scientific Engineering

Principal Investigator: Manfred Krafczyk, Institute for Computational Modeling in Civil Engineering of the Technische Universität Braunschweig (Germany)

HPC Platform used: SuperMUC of LRZ

Local Project ID: pr53yu

Flow noise during takeoff and landing of commercial aircraft can be substantially reduced by the use of porous surface layers in suitable sections of the airfoil. However, porosity and roughness of surfaces tend to have an adverse effect on the boundary layer and thus on the lift of wings. This motivates the need to be able to predict the aerodynamic effects of porous segments of the wing surface by numerical methods. Due to the inherent requirements of resolving both the turbulence on the scale of an airfoil and the flow inside the pore-scale resolved porous medium, the simulations run on SuperMUC required more than a billion grid nodes on a locally refined three-dimensional mesh.

Computational and Scientific Engineering

Principal Investigator: Univ.-Prof. Dr.-Ing. habil. Michael Breuer, Department of Fluid Mechanics, Helmut-Schmidt-University, Hamburg (Germany)

HPC Platform used: SuperMUC of LRZ

Local Project ID: pr53ne

The interaction between fluids and structures (fluid structure interaction/FSI) is a topic of interest in many science fields. In addition to experimental investigations, numerical simulations have become a valuable tool to foresee complex flow phenomena such as vortex shedding, transition and separation or critical stresses in the structure exposed to the flow. In civil engineering, e.g., structures are exposed to strong variations of the wind, particularly wind gusts, and such high loads can ultimately lead to a complete destruction of the structure. Scientists are leveraging HPC technologies in order to model wind gusts and to comprehend their impact on the FSI phenomenon.

Computational and Scientific Engineering

Principal Investigator: Detlef Lohse (1, 2), Richard Stevens (2), (1) Max-Planck-Institut für Dynamik und Selbstorganisation, Göttingen (Germany), (2) Max Planck Center Twente for Complex Fluid Dynamics and Physics of Fluids Group, University of Twente (The Netherlands)

HPC Platform used: SuperMUC of LRZ

Local Project ID: pr74sa

Turbulent thermal convection plays an essential role in a wide range of natural and industrial settings, from astrophysical and geophysical flows to process engineering. While heat transfer in industrial applications takes place in confined systems, the aspect ratio in many natural instances of convection is huge. Interestingly, flow organization on enormous scales is observed in, for example, oceanic and atmospheric convection. However, our physical understanding of the formation of turbulent superstructures is limited. In this project, we analyze the flow organization within turbulent superstructures and show that their size increases when the thermal driving is increased.

Elementary Particle Physics

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

HPC Platform used: SuperMUC of LRZ

Local Project ID: pr48le

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. In this project, scientists 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, their applicability is being established.

Computational and Scientific Engineering

Principal Investigator: Nikolaus A. Adams, Institute of Aerodynamics and Fluid Mechanics, Technische Universität München

HPC Platform used: SuperMUC of LRZ

Local Project ID: pr45wa

The efficient mixing of fuel and oxidizer is essential in modern combustion engines. Especially in supersonic combustion the rapid mixing of fuel and oxidizer is of crucial importance as the detention time of the fuel-oxidizer mixture in the combustion chamber is only a few milliseconds. The shock-induced Richtmyer-Meshkov instability (RMI) promotes mixing and thus has the potential to increase the burning efficiency of supersonic combustion engines. To study the interaction between RMI and shock-induced reaction waves, which affects the flow field evolution und the mixing significantly, researchers leveraged HPC system SuperMUC to run 3D simulations of reacting shock-bubble interaction.

Computational and Scientific Engineering

Principal Investigator: Prof. Jörg Schumacher, Technische Universität Ilmenau (Germany)

HPC Platform used: SuperMUC of LRZ

Local Project ID: pr62se

Turbulent convection flows in nature and technology often show prominent and nearly regular patterns on their largest scales which we term turbulent superstructures. Their appearance challenges the classical picture of turbulence in which a turbulent flow is considered as a tangle of chaotically moving vortices. Examples for superstructures in nature are cloud streets in the atmosphere or the granulation at the surface of the Sun. In several applications, this structure formation is additionally affected by magnetic fields. Our understanding of the origin of turbulent superstructures and their role for the turbulent transport is presently still incomplete and will be improved by direct numerical simulations of turbulent convection.

Elementary Particle Physics

Principal Investigator: Dénes Sexty, Bergische Universität Wuppertal, IAS/JSC Forschungszenturm Jülich

HPC Platform used: JUQUEEN of JSC

Local Project ID: chwu31

In this study the axion particles are investigated numerically. To guide experimental searches of the axion particle, its mass needs to be estimated theoretically. For this one needs to study the creation mechanisms of the axions in the early universe. The axion fields can form topological defects known as cosmological strings, which are highly energetic string-like excitations which decay into axion particles. The axions are created in a phase transition where a large part of the energy builds strings. In this study we follow the fate of the axion-string network to understand how the axion abundance in the universe is created.

Computational and Scientific Engineering

Principal Investigator: Wolfgang Schröder, Institute of Aerodynamics, RWTH Aachen University (Germany)

HPC Platform used: Hazel Hen of HLRS and JUQUEEN of JSC

Local Project ID: GCS-SOPF (HLRS) and hac31 (JSC)

Researchers of the Institute of Aerodynamics (AIA) at RWTH Aachen University conducted large-scale benchmark simulations on supercomputer Hazel Hen of the High-Performance Computing Center Stuttgart to analyze the interaction of non-spherical particles with turbulent flows. These simulations provide a unique data base for the development of simple models which can be applied to study complex engineering problems. Such models are required in a larger research framework to improve the efficiency of pulverized coal and biomass combustion to significantly reduce the CO2 emissions.

Life Sciences

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

HPC Platform used: SuperMUC of LRZ

Local Project ID: pr74ve

Designing new enzymes is a grand challenge for modern biochemistry, and there are few examples for artificial enzymes with significant catalytic rate accelerations. We have developed a new method for computational enzyme design where we mimic evolution in nature and randomly mutate amino acids using a Metropolis Monte Carlo (MC) procedure. The aim of the method is to identify substitutions that increase the catalytic activity of enzymes. We probe the catalytic activity by quantum mechanics/classical mechanics (QM/MM) calculations, which are important for accurately modeling chemical reactions.

Computational and Scientific Engineering

Principal Investigator: Andreas Kempf, Institute for Combustion and Gas Dynamics, Chair of Fluid Dynamics, University of Duisburg-Essen

HPC Platform used: Hazel Hen of HLRS

Local Project ID: GCS-JFLA

Transient mixing and ignition play a significant role in many systems, where combustion efficiency and emissions are controlled by ignition and mixing dynamics. In the present work, high fidelity simulations of a pulsed fuel injection system are carried out using state of the art numerical tools and high-performance computing. The results contain all parameters that affect ignition dynamics and are mined and analyzed. The physics of transient reactive turbulent jets are thus identified and presented that partners in industry and academia can improve their understanding of the process and work on the design of better combustion devices.

Elementary Particle Physics

Principal Investigator: Kálmán Szabó, Institute for Advanced Simulation at Jülich Supercomputing Centre

HPC Platform used: JUQUEEN of JSC

Local Project ID: hjs00

Using the high-performance computing resources available at the Jülich Supercomputing Centre, scientists computed the mass difference between the up and down quarks. The result has been published in Physical Review Letters.

Environment and Energy

Principal Investigator: Paolo Mori, Institute of Physics and Meteorology, University of Hohenheim

HPC Platform used: Hazel Hen of HLRS

Local Project ID: WRFSFHOA

Regional climate simulations at the convection-permitting scale (< 4 km) have the potential to improve seasonal forecasts, especially where complex topography hinders global models. Due to high computational costs, tests using state-of-the-art ensemble forecasts have not been performed yet. In this one-year case study, a Weather Research and Forecasting (WRF) multi-physics ensemble was used to downscale the SEAS5 ensemble forecast over the Horn of Africa. Reliability of precipitation prediction is improved, although the global model’s biases in temperature and precipitation are not reduced. Measurable added value against the global model is provided for intense precipitation statistics over the Ethiopian highlands.

Materials Sciences and Chemistry

Principal Investigator: Axel U. J. Lode(1) and Alexej I. Streltsov(2), (1)Technische Universität Wien, now: Institute of Physics, Albert-Ludwig University of Freiburg, (2) Institute of Physical Chemistry, Universität Heidelberg

HPC Platform used: Hazel Hen of HLRS

Local Project ID: MCTDHB

Granular matter is typically the result of random pattern formation in a solid, like breaking a glass or pulverizing a rock into pieces of variable sizes. Faraday waves are patterns that appear on a fluid that is perturbed by an external drive that oscillates in resonance. Faraday waves aren't random; in contrast to granular matter, these waves are regular, standing, periodic patterns, seen for instance in liquids in a vessel that is shaken. Surprisingly, granulation and Faraday waves can exist in quantum systems too and, even more surprisingly, they can be produced in the same quantum system: in a gas of trapped atoms cooled very close to absolute zero temperature. When the strength of interactions between atoms is modulated, a Faraday...