COMPUTATIONAL AND SCIENTIFIC ENGINEERING

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.

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.

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 (HLRS), JUQUEEN (JSC)

Local Project ID: GCS-Aflo (HLRS), chac32 (JSC)

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.

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.

Computational and Scientific Engineering

Principal Investigator: Xiangyu Hu , Chair of Aerodynamics and Fluid Mechanics, Technische Universität München

HPC Platform used: SuperMUC and SuperMUC-NG of LRZ

Local Project ID: pr53vu

As a Lagrangian method, Smoothed Particle Hydrodynamics (SPH) has been explored and demonstrated for a wide range of applications. Several open-source frameworks exist for the large-scale parallel simulation of particle-based methods in which the resolution of simulation is fixed. Some preliminary work has also been published to tackle the difficulties encountered in extending codes with adaptive-resolution capability. However, the support for fully parallelized adaptive-resolution in distributed systems is generally still limited in the aforementioned codes. This research project focuses on an alternative approach by introducing a new multi-resolution parallel framework employing several algorithms from previous work.

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.

Computational and Scientific Engineering

Principal Investigator: Christian Hasse , Simulation of Reactive Thermo-Fluid Systems, Technische Universität Darmstadt

HPC Platform used: SuperMUC of LRZ

Local Project ID: pr74li

A series of highly resolved direct numerical simulations (DNSs) of temporally evolving turbulent non-premixed jet flames was conducted on the SuperMUC of LRZ. Two promising approaches were used to analyze the databases. The first approach, on-the-fly tracking flamelet structure, helps to understand the effects of neglecting tangential diffusion (TD) on the performance of classical flamelet models. The second approach - dissipation elements – helps to develop possible closure strategies for including flame-tangential effects in the flamelet models. Moreover, TD was used as an important performance indicator to assess tabulation strategies, differential diffusion effects, and Soret effects in turbulent non-premixed combustion.

Computational and Scientific Engineering

Principal Investigator: Luis Cifuentes , Chair of Fluid Dynamics, University of Duisburg-Essen

HPC Platform used: SuperMUC of LRZ

Local Project ID: pr53fa

A GCS large-scale project under leadership of Dr.-Ing. Cifuentes of the University of Duisburg-Essen aims at understanding the physics of entrainment in turbulent premixed flames. This research characterizes the entrainment processes through the study and comparison of the flame front and the enstrophy interface. This is an essential issue in reactive turbulent flows, because a better understanding of the dynamics of the flame front and the enstrophy interface leads to better predictions of flame instabilities and scalar structures.

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: 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.