# Projects

Find out about the latest applications running on the GCS supercomputers. For projects from specific research fields, please choose from the list in the left column.

## Two-Phase-Flows in Francis and Pump Turbines

In the last decades, hydraulic machines 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 suitable to give a better understanding of the physical processes acting at off-design conditions. The goal of this project is to give an insight in the capabilities of two-phase simulations for hydraulic machines and determine the range for safe operation.

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

**HPC Platform:** Hazel Hen of HLRS - **Date published:** July 2016

**More: Two-Phase-Flows in Francis and Pump Turbines …**

## Investigations into Turbulent Flames with Detailed Chemistry and Detailed Transport

Turbulence-chemistry interaction in well characterized partially premixed and premixed laboratory-scale experiments has been investigated numerically by two different methods (M1 & M2) based on the large eddy simulation (LES) technique. It could be shown that the developed transported filtered density function method (M1) is capable of reproducing the turbulence chemistry interaction in the investigated opposed jet flame configurations. The flame resolved simulations (M2) revealed the importance of flame wrinkling and scalar geometry for flame propagation and allowed for further development of sub-filter models for future LES.

**Principal Investigator:** Andreas Kempf, Institut für Verbrennung und Gasdynamik, Lehrstuhl Fluiddynamik, Universität Duisburg-Essen (Germany)

**HPC Platform:** JUQUEEN of JSC - **Date published:** July 2016

**More: Investigations into Turbulent Flames with Detailed Chemistry and Detailed Transport …**

## Collisions of Small Particles in the Wake of a Sphere

Using high resolution direct numerical simulations of a flow seeded with particles around a sphere, an international research team aimed at studying the hydrodynamic problem of collisions among particles in the potentially turbulent wake of a sphere. HPC system JUQUEEN of JSC served as computing platform for this challenging simulation project.

**Principal Investigator:** Rainer Grauer, Institut für Theoretische Physik, Ruhr-Universität Bochum (Germany)

**HPC Platform:** JUQUEEN of JSC - **Date published:** July 2016

**More: Collisions of Small Particles in the Wake of a Sphere …**

## Global Kinetic Modelling of Space Weather – With Extreme Scalability (VLASIATOR)

Space weather is an increasingly important aspect for our technology-dependent society. Modelling space weather is difficult, however, a Finnish team has succeeded in something that was said to be impossible: an accurate simulation of the large-scale near-Earth space environment. PRACE Tier-0 grant from Hazel Hen (HLRS, Stuttgart) both allowed the Vlasiator team to discover new space physics phenomena, and significantly helped in the acceptance of the second European Research Council grant awarded to the project PI in fall 2015.

**Principal Investigator:** Minna Palmroth, Earth Observation Finnish Meteorological Institute, Helsinki (Finland)

**HPC Platform:** Hazel Hen of HLRS - **Date published:** July 2016

**More: Global Kinetic Modelling of Space Weather – With Extreme Scalability (VLASIATOR) …**

## Gravitational Waves From Early Universe Phase Transitions

Gravitational waves are ripples in spacetime, predicted by Einstein already a century ago. With the announcement earlier this year that gravitational waves had been successfully detected from two black holes merging, attention now turns to other potential sources of gravitational waves. Such sources include dramatic events that may have occurred very early in the history of the universe. Understanding these other sources also informs the design of future gravitational wave detectors, such as the European Space Agency (ESA) project eLISA.

**Principal Investigator:** David Weir, Department of Mathematics and Natural Sciences, University of Stavanger (Norway)

**HPC Platform:** Hazel Hen of HLRS - **Date published:** July 2016

**More: Gravitational Waves From Early Universe Phase Transitions …**

## Dynamical Processes in Semiconductor Nanostructures

Researchers use ab-initio density functional theory (DFT) to unravel the effects of lattice vibrations on the electronic and optical properties of semiconductor nanostructures and how they can influence carrier dynamics in the femtoseconds to tens of picosecond time range. The scientific interest resides in the understanding of fundamental physics and in a reliable assessment of the importance of carrier relaxation, dephasing, and temperature effects, which are relevant for semiconductor nanodevices.

**Principal Investigator:** Gabriel Bester, University of Hamburg and the Hamburg Centre for Ultrafast Imaging (Germany)

**HPC Platform:** Hazel Hen of HLRS - **Date published:** June 2016

**More: Dynamical Processes in Semiconductor Nanostructures …**

## Investigation of the Influences of Gaps at the Runner Blade for an Axial Turbine Using Hybrid Turbulence Models

The operation range of hydraulic turbines is increasing more and more to guarantee the power system stability of the electric grid due to the increased amount of electric power generated by unregulated renewable energy like wind and photovoltaic. Therefore, hydraulic turbines are operated in off-design conditions where highly transient phenomena can occur. Standard approaches which are used for the design process of hydraulic machines are no longer suitable to predict the correct flow field in these operating points. Advanced turbulence models and high mesh resolutions are applied to increase the accuracy of the simulations.

**Principal Investigator:** Bernd Junginger, Institute of Fluid Mechanics and Hydraulic Machinery, University of Stuttgart (Germany)

**HPC Platform:** Hazel Hen of HLRS - **Date published:** June 2016

**More: Investigation of the Influences of Gaps at the Runner Blade for an Axial Turbine Using Hybrid Turbulence Models …**

## In Silico Exploration of Prebiotic Peptide Synthesis by Ab Initio Metadynamics

Prebiotic Chemistry is the study of those chemical reactions that could have taken place on the early Earth by which, starting from small molecules like H_{2}O, NH_{3}, CO_{2}, SH_{2} or simple amino acids, more complex molecules were formed. This leads eventually to the formation of biomacromolecules as we know them from today's life, for instance proteins, RNA or DNA but also lipids. Advanced computer simulations in conjunction with large-scale HPC facilities and scalable codes allow one to investigate at the very molecular level not only how these reactions could have happened, but more importantly how they are affected by factors like temperature, pressure, or the presence of mineral surfaces to name but a few.

**Principal Investigator:** Dominik Marx, Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum (Germany)

**HPC Platform:** JUQUEEN of JSC - **Date published:** June 2016

**More: In Silico Exploration of Prebiotic Peptide Synthesis by Ab Initio Metadynamics …**

## Numerical Investigation of Ship-Propeller Cavitation with Full Description of Shock-Wave Dynamics

A project of scientists of the Institute of Aerodynamics and Fluid Mechanics at the Technische Universität München focused on the numerical investigation of cavitating flow in the context of ship propellers. A key aspect of this project was to develop the ability to assess local flow aggressiveness and to quantify the potential of material erosion.

**Principal Investigator:** Bernd Budich, Technische Universität München (Germany)

**HPC Platform:** SuperMUC of LRZ - **Date published:** June 2016

**More: Numerical Investigation of Ship-Propeller Cavitation with Full Description of Shock-Wave Dynamics …**

## Leading Hadronic Contribution to the Anomalous Magnetic Moment of the Muon

The Standard Model of particle physics is one of the great scientific achievements of the 20^{th }century. After confirmation of the existence of the Higgs boson in 2013, physicists are now keen to see whether there is anything beyond the theory. Scientists of CNRS and Aix-Marseille University have been been using lattice QCD to see whether a certain experimental measurement is indeed a glimpse of new fundamental physics.

**Principal Investigator:** Laurent Lellouch, National Center for Scientific Research/CNRS & Aix-Marseille University (France)

**HPC Platform:** JUQUEEN of JSC - **Date published:** June 2016

**More: Leading Hadronic Contribution to the Anomalous Magnetic Moment of the Muon …**

## NACRE - Micromechanics of Biocomposite Materials

Composite materials made up of inorganic and biological matter present remarkable properties including fracture resistance, toughness and strength. A team of scientists of the Heidelberg Institute for Theoretical Studies has been investigating the mechanical properties of nacre, a material that possesses great stability due to its elaborate hierarchical nanostructures.

**Principal Investigator**: Frauke Gräter, Heidelberg Institute for Theoretical Studies (Germany)

**HPC Platform:** Hornet of HLRS - **Date published: **June 2016

**More: NACRE - Micromechanics of Biocomposite Materials …**

## Magnetic Reconnection in 3D

The process of magnetic reconnection — when magnetic fields in plasma reconfigure and explosively release thermal and kinetic energy — is only just beginning to be understood. Professor Giovanni Lapenta has been carrying out simulations on SuperMUC of how these events can cause chain reactions that very quickly fill vast volumes of space. This data is now being verified with the recent NASA Magnetospheric MultiScale Mission that is measuring magnetic reconnection events around the Earth.

**Principal Investigator:** Giovanni Lapenta, KU Leuven (Belgium)

**HPC Platform:** SuperMUC of LRZ - **Date published:** June 2016

**More: Magnetic Reconnection in 3D …**

## RBTC - Towards Ultimate Rayleigh-Benard and Taylor-Couette Turbulence

Rayleigh-Benard flow (the flow in a box heated from below and cooled from above) and Taylor-Couette flow (the flow between two counter-rotating cylinders) are the two paradigmatic systems in the physics of fluids, and many new concepts have been tested with them. Researchers from the Physics of Fluids group at the University of Twente have been carrying out simulations of these systems on HLRS supercomputers to try and improve our understanding of turbulence.

**Principal Investigator:** Detlef Lohse, University of Twente (The Netherlands)

**HPC Platform:** Hermit of HLRS - **Date published:** May 2016

**More: RBTC - Towards Ultimate Rayleigh-Benard and Taylor-Couette Turbulence …**

## Physics of the Solar Chromosphere

A simulation project, run on SuperMUC, targets the intrinsic physics of the chromosphere in order to understand its mass and energy budgets and transfer mechanisms. Elucidating these is a principal quest of solar physics, a necessary step towards better space-weather prediction, and of interest to general astrophysics using the Sun as a close-up Rosetta-Stone star and to plasma physics using the Sun and heliosphere as a nearby laboratory. The project aims at a breakthrough in our understanding of the solar chromosphere by developing sophisticated radiation-magnetohydrodynamic simulations.

**Principal Investigator:** Mats Carlsson, Institute of Theoretical Astrophysics, University of Oslo (Norway)

**HPC Platform:** SuperMUC of LRZ - **Date published:** May 2016

**More: Physics of the Solar Chromosphere …**

## Lagrangian **S**pace-**Ti**me Methods for **Mul**ti-Fluid Problems on **U**nstructured Me**s**hes (STiMulUs)

Researchers leveraged the computing power of SuperMUC for the development of finite volume Lagrangian numerical schemes on multidimensional unstructured meshes for fluid dynamic problems. The numerical algorithms developed in project STiMulUs are designed to be high order accurate in space as well as in time, requiring even more information to be updated and recomputed continuously as the simulation goes on.

**Principal Investigator:** Walter Boscheri, Department of Civil, Environmental and Mechanical Engineering, University of Trento (Italy)

**HPC Platform:** SuperMUC of LRZ - **Date published:** May 2016

**More: Lagrangian Space-Time Methods for Multi-Fluid Problems on Unstructured Meshes (STiMulUs) …**

*In Silico* Study of the Optical Properties of Oxyluciferins

Light emission in the fireflies is the product of a reaction catalysed by an enzyme named luciferase. The product of this reaction is the oxyluciferin, which in turn emits visible light. Scientists studied the interplay between the structural and absorption properties of oxyluciferins with an unprecedented level of accuracy.

**Principal Investigator:** Leonardo Guidoni, University of L’Aquila, Trieste (Italy)

**HPC Platform:** JUQUEEN of JSC - **Date published:** May 2016

**More: In Silico Study of the Optical Properties of Oxyluciferins …**

## Kinetic Model of Ethylene Epoxidation on Ag Surfaces

One of the major challenges in understanding silver’s unique ability to catalyze the partial oxidation of ethylene to ethylene oxide is identifying how different forms of oxygen on silver react with ethylene. Using a highly parallelizable open-source DFT code for electronic-structure calculations and materials modeling at the nanoscale, scientists aimed at achieving a realistic picture of the chemistry of ethylene epoxidation.

**Principal Investigator:** Simone Piccinin, National Research Council-Istituto Officina dei Materiali (CNR-IOM), Trieste (Italy)

**HPC Platform:** Hermit of HLRS - **Date published:** April 2016

**More: Kinetic Model of Ethylene Epoxidation on Ag Surfaces …**

## Nucleon Structure Using Lattice QCD Simulation with Physical Pion Mass

Scientists are leveraging HPC system SuperMUC for state-of-the-art lattice Quantum Chromodynamics (QCD) simulations. Using these Tier-0 computational resources, the team of international researchers has pioneered the calculation of key observables that characterize the structure of protons and neutrons, collectively referred to as nucleons.

**Principal Investigator:** Constantia Alexandrou, University of Cyprus and The Cyprus Institute (Cyprus)

**HPC Platform:** SuperMUC of LRZ - **Date published:** April 2016

**More: Nucleon Structure Using Lattice QCD Simulation with Physical Pion Mass …**

## Simulation of Turbulent Flow With a CFD Method in a Power-Plant Containment

Two-phase flows with water droplets greatly affect the thermal-hydraulic behaviour in the containment of a Pressurized Water Reactor (PWR). In order to predict the local thermal-hydraulic behaviour in a real containment in the case of a severe accident, scientists of the University of Stuttgart generated a three-dimensional geometry of a model containment based on a German PWR.

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

**HPC Platform:** Hermit of HLRS - **Date published:** April 2016

**More: Simulation of Turbulent Flow With a CFD Method in a Power-Plant Containment …**

## Model Development for Meteorological Applications

The dynamic behavior of the atmosphere is driven by processes on a wide range of spatial and temporal scales. In a project run by scientists of the Heidelberg University, those parts of model systems which describe the fluid dynamics and the temperature evolution were investigated. The models are formulated in terms of the velocity, temperature, pressure, and density. The researchers employ a hierarchy of different physical models with an increasing degree of complexity. The task of predicting the evolution of tropical cyclones is a typical challenging example.

**Principal Investigator:** Martin Baumann, Universitätsrechenzentrum, Ruprecht-Karls-Universität Heidelberg (Germany)

**HPC Platform:** JUQUEEN of JSC - **Date published:** March 2016

**More: Model Development for Meteorological Applications …**

## Simulation of Unsteady Loads and Wakes of Wind Turbines at Turbulent Atmospheric Inflow Conditions

In order to develop economic, efficient, and reliable wind turbines, the knowledge of the mechanisms that evoke transient aerodynamic loads effecting blades, tower, and the nacelle is essential. Using high performance computing technologies, researchers of the University of Stuttgart used high-fidelity Computational Fluid Dynamics (CFD) methods to accurately predict these unsteady loads. Particular interest was paid on the interaction of wind turbine and atmospheric boundary layer.

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

**HPC Platform:** Hermit and Hornet of HLRS - **Date published:** March 2016

**More: Simulation of Unsteady Loads and Wakes of Wind Turbines at Turbulent Atmospheric Inflow Conditions …**

## Discontinuous Galerkin Methods for Detached Eddy Simulation

Despite the great success of current state-of-the-art fluid flow solvers, the continuing development of computing hardware necessitates new numerical methods for flow simulations. High order methods on unstructured grids like Discontinuous Galerkin discretisations deliver highly accurate results and allow for unprecedented parallelisation efficiency at huge numbers of cores. The project aims to transfer the infrastructure technology (overlapping Chimera grids, mesh movement and deformation, convergence acceleration) from conventional to such advanced solvers to allow application to relevant engineering problems like helicopter simulations in the mid-term future.

**Principal Investigator:** Manuel Keßler, Institut für Aerodynamik und Gasdynamik (IAG), Universität Stuttgart (Germany)

**HPC Platform:** Hornet and Hazel Hen of HLRS - **Date published:** March 2016

**More: Discontinuous Galerkin Methods for Detached Eddy Simulation …**

## High Fidelty Simulations of Rotorcraft Aerodynamics and Aeroacoustics (HELISIM)

The helicopter and aeroacoustics group of IAG runs extensive aerodynamics and aeromechanics simulations of rotorcraft in order to understand not only basic parameters as power requirements or loads on the rotor blades but also to predict acoustic footprints and gain a deeper insight into the interactions between different helicopter components. For this purpose, the group runs simulation setups on HLRS supercomputer Hazel Hen of a magnitude beyond 200 million cells with fifth order accuracy and even up to half a billion cells for selected cases, delivering results directly comparable to real flight test data at unparalleled accuracy.

**Principal Investigator:** Manuel Keßler, Institut für Aerodynamik und Gasdynamik (IAG), Universität Stuttgart (Germany)

**HPC Platform:** Hazel Hen of HLRS - **Date published:** March 2016

**More: High Fidelty Simulations of Rotorcraft Aerodynamics and Aeroacoustics (HELISIM) …**

## Pair-Dominated Plasmas and Radiation in Ultra Intense Fields

Leveraging the petascale computing power of SuperMUC, an international team of researchers performed 2D/3D simulations of laser absorption in dense electron-positron plasmas self-consistently created via electromagnetic cascades. Their numerical findings provide a set of laser parameters to optimize the conversion of optical photons into pairs and gamma rays allowing to mimic extreme astrophysical scenarios and their radiation signatures.

**Principal Investigator:** Thomas Grismayer, GoLP/IPFN, Instituto Superior Técnico, Lisboa (Portugal)

**HPC Platform:** SuperMUC of LRZ - **Date published:** March 2016

**More: Pair-Dominated Plasmas and Radiation in Ultra Intense Fields …**

## Investigation of Delta Wing Time Dependent Flow Characteristics with Lattice-Boltzmann Method

The project Investigation of Delta Wing Time Dependent Flow Characteristics with Lattice-Boltzmann Method is carried out by the Technische Hochschule Ingolstadt, Faculty of Mechanical Engineering, at the High Performance Computing Center Stuttgart. It focuses on the numerical investigation of the delta wing flow under various aspects such as sweep angle variation, sharp or round leading edges, as well as high and lower Reynolds numbers with a Lattice-Boltzmann PowerFLOW solver provided by Exa.

**Principal Investigator:** Erol Oezger, Technische Hochschule Ingolstadt (Germany)

**HPC Platform:** Hermit and Hornet of HLRS - **Date published:** March 2016

**More: Investigation of Delta Wing Time Dependent Flow Characteristics with Lattice-Boltzmann Method …**

## Lattice QCD + QED: Towards a Quantitative Understanding of the Stability of Matter

Leveraging the petascale computing power of HPC system JUQUEEN, scientists at Deutsches Elektronen-Synchrotron (DESY) in Hamburg, Germany, included for the first time both Quantum Chromodynamics (QCD) and Quantum Electrodynamics (QED) in a nonperturbative calculation. This allowed the physicists to predict isospin breaking effects in the meson, baryon and quark sectors from first principles, and in particular the n - p mass difference.

**Principal Investigator: **Gerrit Schierholz, DESY Hamburg (Germany)

**HPC-Platform: **JUQUEEN of JSC – **Date published:** February 2016

**More: Lattice QCD + QED: Towards a Quantitative Understanding of the Stability of Matter …**

## High Accuracy Molecular Dynamics Simulation of Fluids at Interfaces

Mechanical properties of liquid droplets are highly relevant in materials science and manufacturing. The thermodynamics of liquid droplets are also critical for many applications in energy technology, meteorology, and other fields where nucleation in a supersaturated vapour plays an important role. Using molecular dynamics simulations on SuperMUC, researchers investigated these phenomena to capture the length and time scale dependence of finite-size effects on the properties and the dynamics of nano-dispersed phases.

**Principal Investigator:** Martin Horsch, Laboratory of Engineering Thermodynamics, University of Kaiserslautern (Germany)

**HPC Platform:** SuperMUC of LRZ - **Date published:** February 2016

**More: High Accuracy Molecular Dynamics Simulation of Fluids at Interfaces …**

## Computational Modelling of a Lipase at a Hydrophobic Substrate Interface

To gain further insight into how lipases catalyze the hydrolysis of water-insoluble triglycerides like fats and oils, scientists leveraged the computing power of the HLRS HPC infrastructure for a computational modelling of a lipase at a hydrophobic substrate interface. In total, more than 1μs of molecular dynamics simulations were performed on a system consisting of 100,000 atoms.

**Principal Investigator**: Jürgen Pleiss, Institute of Technical Biochemistry, University of Stuttgart (Germany)

**HPC Platform:** Hermit of HLRS - **Date published: **February 2016

**More: Computational Modelling of a Lipase at a Hydrophobic Substrate Interface …**

## Binding Specificity of Biomolecular Interactions

While some proteins of a biological cell are bound to cellular structures others diffuse freely. Especially in a crowded cellular environment, proteins constantly bump into other proteins which sometimes leads to biologically meaningful contact of the two proteins–the binding partners may either remain bound or a chemical reaction may take place. Performing atomistic molecular dynamics simulations on SuperMUC, bioinformaticists try to unravel the biophysical principles underlying such “specific” biomolecular interactions.

**Principal Investigator**: Volkhard Helms, Center for Bioinformatics, Saarland University, Saarbrücken (Germany)

**HPC Platform:** SuperMUC of LRZ - **Date published: **February 2016

**More: Binding Specificity of Biomolecular Interactions …**

## Direct Numerical Simulation of an Adverse Pressure Gradient Turbulent Boundary Layer

An international research project aimed at investigating the structure and dynamics of wall-bounded turbulence in adverse pressure gradient environments has resulted in the first Direct Numerical Simulation (DNS) of a self-similar turbulent boundary layers (TBL) in a strong adverse pressure gradient (APG) environment at the verge of separation up to a Reynolds number based on the momentum thickness of 10^{4}.

**Principal Investigator:** Javier Jiménez, Universidad Politécnica de Madrid (Spain)

**HPC Platform:** SuperMUC of LRZ - **Date published:** February 2016

**More: Direct Numerical Simulation of an Adverse Pressure Gradient Turbulent Boundary Layer …**