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Aeroacoustic analysis using natural Helmholtz–Hodge decomposition

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


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/
Document Type:Article
Title:Aeroacoustic analysis using natural Helmholtz–Hodge decomposition
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Haufe, DanielInstitut für Grundlagen der Elektrotechnik und Elektronik, Professur für Mess- und Prüftechnik, TU DresdenUNSPECIFIED
Gürtler, JohannesInstitut für Grundlagen der Elektrotechnik und Elektronik, Professur für Mess- und Prüftechnik, TU DresdenUNSPECIFIED
Bake, FriedrichFriedrich.Bake (at) dlr.dehttps://orcid.org/0000-0002-3235-428X
Czarske, JürgenInstitut für Grundlagen der Elektrotechnik und Elektronik, Professur für Mess- und Prüftechnik, TU DresdenUNSPECIFIED
Date:March 2018
Journal or Publication Title:Journal of Sensors and Sensor Systems
Refereed publication:Yes
Open Access:Yes
Gold Open Access:Yes
In ISI Web of Science:No
DOI :10.5194/jsss-7-113-2018
Page Range:pp. 113-122
Publisher:Copernicus Publications
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
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:27 Aug 2018 08:33

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