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Chapter and Conference Paper
Aeroacoustic Simulations of Ducted Axial Fan and Helicopter Engine Nozzle Flows
The flow and the acoustic field of an axial fan and a helicopter engine jet are computed by a hybrid fluid dynamics – computational aeroacoustics method. For the predictions of the flow field a high-fidelity, ...
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Chapter and Conference Paper
Investigation of the Effect of a Realistic Nozzle Geometry on the Jet Development
Highly resolved large-eddy simulations (LES) of a helicopter engine jet including the nozzle geometry are performed. A flow solver for compressible flow based on hierarchically refined Cartesian meshes and a c...
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Chapter and Conference Paper
Simulation of a Helicopter Engine Jet Including a Realistic Nozzle Geometry
of a helicopter engine jet at a Reynolds number of Re = 750,000 and a Mach number of M = 0.341 is performed. The influence of a realistic nozzle geometry on the jet properties is analyzed by using hig...
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Chapter and Conference Paper
Large-Scale Simulations of a Non-generic Helicopter Engine Nozzle and a Ducted Axial Fan
Large-eddy simulations (LESs) of a helicopter engine jet and an axial fan are performed by using locally refined Cartesian hierarchical meshes. For the computations a high-fidelity, massively parallelized solv...
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Chapter and Conference Paper
A Hybrid Discontinuous Galerkin-Finite Volume Method for Computational Aeroacoustics
A hybrid method for a fully coupled determination of aerodynamic sound is introduced. From the instantaneous velocity and vorticity, determined by approximate solutions of the Navier-Stokes equations, acoustic...
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Chapter and Conference Paper
CFD/CAA Simulations on HPC Systems
In this paper, a highly scalable numerical method is presented that allows to compute the aerodynamic sound from a turbulent flow field on HPC systems. A hybrid CFD-CAA method is used to compute the flow and t...
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Chapter and Conference Paper
Software Cost Analysis of GPU-Accelerated Aeroacoustics Simulations in C++ with OpenACC
Aeroacoustics simulations leverage the tremendous computational power of today’s supercomputers, e.g., to predict the noise emissions of airplanes. The emergence of GPUs that are usable through directive-based...
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Article
Drag Reduction Via Spanwise Transversal Surface Waves at High Reynolds Numbers
The impact of transversal spanwise traveling surface waves on the wall-shear stress distribution of high Reynolds number turbulent boundary layer flows is analyzed using high-resolution large-eddy simulations....
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Chapter and Conference Paper
Towards Large Multi-scale Particle Simulations with Conjugate Heat Transfer on Heterogeneous Super Computers
We present numerical methods based on hierarchical Cartesian grids for the simulation of particle flows of different length scales. These include Eulerian-Lagrangian approaches for fully resolved moving partic...
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Chapter and Conference Paper
Simulation of Transonic Airfoil Flow Using a Zonal RANS-LES Method
This paper presents a method for a synthetic turbulence generation (STG) to be used in a segregated hybrid Reynolds-averaged Navier-Stokes (RANS)-Large-Eddy Simulation (LES) approach. The present method separa...
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Chapter
Numerical Investigation of the Combined Effects of Gravity and Turbulence on the Motion of Small and Heavy Particles
Numerical studies [1, 2] show that the influence of gravity and turbulence on the motion of small and heavy particles is not a simple superposition. However, in [3] it is shown that these studies may be artifi...
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Chapter
Partitioned Fluid-Structure Interaction on Solution-Adaptive Hierarchical Cartesian Grids
A solution-adaptive hierarchical Cartesian cut-cell method is validated for fluid-structure interaction problems involving rigid bodies. The response of a tandem configuration of elastically supported cylin...
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Chapter
A Level-Set Based Cartesian Grid Method to Simulate In-Cylinder Flow
This work discusses the extension of a three-dimensional, strictly conservative Cartesian cut-cell based method to meet the requirements for the simulation of in-cylinder flow and other flows bounded by comple...
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Chapter and Conference Paper
Large-Eddy Simulation of Supersonic Film Cooling at Incident Shock-Wave Interaction
The impact of shock waves on supersonic cooling films is studied using large-eddy simulations (LES). A laminar cooling film is injected through a slot at a Mach number Ma i ...
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Chapter and Conference Paper
Efficient Coupling of an Eulerian Flow Solver with a Lagrangian Particle Solver for the Investigation of Particle Clustering in Turbulence
Numerical studies show that particles suspended in a turbulent flow tend to cluster due to their inertia (Wang and Maxey, J. Fluid Mech. 256:27–68, 1993; Bec et al., Phys. Rev. Lett. 98:084502, 2007). It was s...
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Chapter
Sensor Controlled Zonal RANS-LES Method
A sensor was developed to detect aerodynamic regions in the computational domain of aerodynamic relevant flows where a common RANS simulation does no longer provide physically reliable results. These regions o...
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Chapter and Conference Paper
Industrial Turbulence Simulations at Large Scale
The most important aspect for simulations in industrial design processes is the time to solution. To obtain highly detailed results nevertheless, massive computational resources have to be deployed. Feasibilit...
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Chapter and Conference Paper
Synthetic Turbulence Generation for a Zonal RANS-LES Method
A synthetic turbulence generation (STG) method for flows at low and high Reynolds and Mach numbers to provide LES inflow boundary conditions of zonal Reynolds-averaged Navier-Stokes (RANS)- large-eddy simulati...
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Chapter and Conference Paper
Large-Eddy Simulation of Supersonic Film Cooling at Finite Pressure Gradients
Large-eddy simulations are performed to analyze film cooling in supersonic combustion ramjets (Scramjets). The transonic film cooling flow is injected through a slot parallel to a Ma=2.44 main stream with a fully...
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Chapter and Conference Paper
Highly Efficient and Scalable Software for the Simulation of Turbulent Flows in Complex Geometries
This paper investigates the efficiency of simulations for compressible turbulent flows with noise generation in complex geometries. It analyzes two different approaches and their suitability with respect to qu...
