Haufe, Daniel and Gürtler, Johannes and Schulz, Anita and Bake, Friedrich and Enghardt, Lars and Czarske, Jürgen (2018) Aeroacoustic analysis using natural Helmholtz–Hodge decomposition. Journal of Sensors and Sensor Systems, 7, pp. 113-122. Copernicus Publications. doi: 10.5194/jsss-7-113-2018. ISSN 2194-8771.
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Official URL: https://doi.org/10.5194/jsss-7-113-2018
Abstract
The analysis of aeroacoustic phenomena is crucial for a deeper understanding of the damping mechanisms of a sound-absorbing bias flow liner (BFL). For this purpose, simultaneous measurements of the sound field and the flow field in a BFL are required. The fluid velocity can serve as the measurand, where both the acoustic particle velocity and the aerodynamic flow velocity contribute and, thus, can be acquired simultaneously. However, there is a need to separate these two quantities to distinguish between them. This is challenging because they generally coincide with each other in the time domain. Due to the interaction of sound and flow in a BFL, both velocities also overlap in the temporal frequency domain, having a coherent oscillation at the acoustic frequency. For this reason, the recently developed natural Helmholtz–Hodge decomposition (NHHD) is applied to separate both quantities from the measured oscillation velocity field in the spatial domain. The evaluation of synthetic vector field data shows that the quality of the decomposition is enhanced when a smaller grid size is chosen. The velocity field in a generic BFL, necessarily recorded within a three-dimensional region of interest at more than 4000 measurement locations, is evaluated using NHHD. As a result, the measured oscillation velocity in the BFL is dominated by the flow that is related to vortices and also by irrotational aerodynamic flow. Moreover, indications for an aeroacoustic source near the facing sheet of the liner are revealed.
Item URL in elib: | https://elib.dlr.de/120866/ | ||||||||||||||||||||||||||||
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Document Type: | Article | ||||||||||||||||||||||||||||
Title: | Aeroacoustic analysis using natural Helmholtz–Hodge decomposition | ||||||||||||||||||||||||||||
Authors: |
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Date: | March 2018 | ||||||||||||||||||||||||||||
Journal or Publication Title: | Journal of Sensors and Sensor Systems | ||||||||||||||||||||||||||||
Refereed publication: | Yes | ||||||||||||||||||||||||||||
Open Access: | Yes | ||||||||||||||||||||||||||||
Gold Open Access: | Yes | ||||||||||||||||||||||||||||
In SCOPUS: | Yes | ||||||||||||||||||||||||||||
In ISI Web of Science: | Yes | ||||||||||||||||||||||||||||
Volume: | 7 | ||||||||||||||||||||||||||||
DOI: | 10.5194/jsss-7-113-2018 | ||||||||||||||||||||||||||||
Page Range: | pp. 113-122 | ||||||||||||||||||||||||||||
Publisher: | Copernicus Publications | ||||||||||||||||||||||||||||
ISSN: | 2194-8771 | ||||||||||||||||||||||||||||
Status: | Published | ||||||||||||||||||||||||||||
Keywords: | Separation acoustic and aerodynamic field | ||||||||||||||||||||||||||||
HGF - Research field: | Aeronautics, Space and Transport | ||||||||||||||||||||||||||||
HGF - Program: | Aeronautics | ||||||||||||||||||||||||||||
HGF - Program Themes: | propulsion systems | ||||||||||||||||||||||||||||
DLR - Research area: | Aeronautics | ||||||||||||||||||||||||||||
DLR - Program: | L ER - Engine Research | ||||||||||||||||||||||||||||
DLR - Research theme (Project): | L - Turbine Technologies (old) | ||||||||||||||||||||||||||||
Location: | Berlin-Charlottenburg | ||||||||||||||||||||||||||||
Institutes and Institutions: | Institute of Propulsion Technology > Engine Acoustic | ||||||||||||||||||||||||||||
Deposited By: | Bake, Dr.-Ing. Friedrich | ||||||||||||||||||||||||||||
Deposited On: | 09 Jul 2018 10:32 | ||||||||||||||||||||||||||||
Last Modified: | 14 Dec 2019 04:22 |
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