A5060285360- Aerodynamics and Acoustics in Jet Flows
- Acoustic Wave Phenomena Research
- Speech and Audio Processing
- Magnetic confinement fusion research
- Fusion materials and technologies
- Wind and Air Flow Studies
- Particle accelerators and beam dynamics
- Noise Effects and Management
- Electron Spin Resonance Studies
- Fluid Dynamics and Turbulent Flows
- Superconducting Materials and Applications
- Underwater Acoustics Research
- Flow Measurement and Analysis
- Advanced Adaptive Filtering Techniques
- Nuclear Physics and Applications
- Image and Signal Denoising Methods
- Vehicle Noise and Vibration Control
- Astro and Planetary Science
- Seismic Waves and Analysis
- Plasma Diagnostics and Applications
- Fluid Dynamics and Vibration Analysis
- Laser-Plasma Interactions and Diagnostics
- Hydrology and Sediment Transport Processes
- Meteorological Phenomena and Simulations
- Structural Health Monitoring Techniques
Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)
2015-2023
Massachusetts Institute of Technology
1993-2015
Fusion Academy
2015
Plasma Technology (United States)
2015
Princeton Plasma Physics Laboratory
1993-1995
Princeton University
1995
Joint European Torus
1993
Oak Ridge National Laboratory
1993
University of Wisconsin–Madison
1993
National Technical Information Service
1993
Measurements of impurities in Alcator C-Mod indicate that the pedestal region, significant poloidal asymmetries can exist impurity density, ion temperature, and main density. In light observation temperature electrostatic potential are not constant on a flux surface [Theiler et al., Nucl. Fusion 54, 083017 (2014)], technique based total pressure conservation to align profiles measured at separate locations is presented applied. Gyrokinetic neoclassical simulations with XGCa support observed...
Phased arrays are a common tool for detecting aero-acoustical sources in closed or open jet wind tunnels. The usual design process of phased array can be summarized to the following steps: In first step, an ideal sound source is assumed and theoretical output (point-spread function, psf ) calculated given microphone distribution. General shaping parameters minimal distance between two microphones - limiting upper frequency resolution maximum between two (or: aperture size) towards low...
Preparing and pre-testing experimental setups for flight tests is a lengthy but necessary task. One part of this preparation comparing newly available measurement technology with proven setups. In our case, we wanted to compare acoustic Micro-Electro-Mechanical Systems (MEMS) large surface-mounted condenser microphones. The task started the comparison spectra in low-speed wind tunnel environments. After successful completion, challenge was increased similar comparisons transonic tunnel....
The Tokamak Fusion Test Reactor (TFTR) is a large tokamak which has performed experiments with 50:50 deuterium - tritium fuelled plasmas. Since 1993, TFTR produced about 1090 D T plasmas using 100 grams of and producing 1.6 GJ fusion energy. These have significant populations 3.5 MeV alphas (the charged product). research focused on alpha particle confinement, driven modes, heating studies. Maximum power production aided these studies, requiring simultaneously operation at high input energy...
Measurements of the relative toroidal rotation velocities low Z impurity ions have been made in DIII-D tokamak [J. L. Luxon and G. Davis, Fusion Technol. 8, 441 (1985)] plasmas that a strong core pressure gradient reduced anomalous transport. They show differences agree with predictions neoclassical transport theory. The are measured via charge exchange recombination (CER) spectroscopy species. Taking into account non-negligible effect energy dependent cross sections, quantitative agreement...
come from teaching and research institutions in France or abroad, public private centers.
Beamforming methods for sound source localization are usually based on free-field Green's functions to model the propagation between and microphones. This assumption is known be incorrect many industrial applications beamforming results can suffer from this inconsistency regarding both, main lobe width dynamic range. The aim of paper investigate whether use numerically calculated functions, which include diffraction reflection path microphones, improve measurements. current test cases...
This paper presents a large 6~m x 3~m aperture 7200 MEMS microphone array. The array is designed so that sub-arrays with optimized point spread functions can be used for beamforming and thus, enable the research of source directivity in wind tunnel facilities. total consists modular 800 panels, each consisting four unique PCB board designs. architecture allows time-synchronized measurement an arbitrary number panels size sensors. installed without gap array's pattern avoids high sidelobes...
The exact positions of microphones are mandatory when using them as an array to apply beamforming algorithms. Nevertheless obtain these in the three dimensional space is challenging. In this paper, further developments acoustic calibration unit, proposed 2009 by Lauterbach presented. unit consists several speakers and a reference microphone arbitrary amount target via triangulation. These calculated not necessarily geometric position microphone, it position, which includes possible phase...
In the field of aeroacoustic source imaging, one seeks to reconstruct acoustic powers from microphone array measurements. For most setups, cannot expect a perfect reconstruction. The main effects that contribute this reconstruction error are data noise and modeling errors. While is accounted for in advanced methods, e.g., by proper regularization strategy, usually neglected. This article proposes an approach extends regularized inverse methods with mechanism takes into account. presented...
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation S. D. Scott, Cris W. Barnes, Ernst, J. Schivell, E. Synakowski, M. G. Bell, R. C. Bush, Fredrickson, B. Grek, K. Hill, A. Janos, L. Jassby, Johnson, Mansfield, Owens, H. Park, T. Ramsey, Stratton, Thompson, Zarnstorff; Parametric variations of ion transport in TFTR. AIP Conf. Proc. 1 May 1994; 284 (1): 19–59....
Aircraft cabin noise measurements in flight are used toto quantify the level, and to identify entry point of acoustic energy into cabin. Sound intensity probes state-of-the-art measurement technique for this task. During measurements, additional sound absorbing material is ease rather harsh environment inside In order decrease expensive in-flight time, an array approach was chosen. This probe consists 512 MEMS-Microphones. Depending on frequency, these microphones can be combined as hundreds...