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Swirl–nozzle interaction experiment: quasi-steady model-based analysis

Hirschberg, Lionel and Bake, Friedrich and Knobloch, Karsten and Rudolphi, A. and Kruck, Sebastian and Klose, Oliver and Hulshoff, Steven J. (2021) Swirl–nozzle interaction experiment: quasi-steady model-based analysis. Experiments in Fluids, 62 (175), pp. 1-16. Springer Nature. doi: 10.1007/s00348-021-03271-y. ISSN 0723-4864.

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Official URL: https://doi.org/10.1007/s00348-021-03271-y

Abstract

Measurements of sound due to swirl–nozzle interaction are presented. In the experiment a swirl structure was generated by means of unsteady tangential injection into a steady swirl-free flow upstream from a choked convergent–divergent nozzle. Ingestion of swirl by the choked nozzle caused a mass-flow rate change, which resulted in a downstream-measured acoustic response. The downstream acoustic pressure was found to remain negative as long as the swirl is maintained and reflections from the open downstream pipe termination do not interfere. The amplitude of this initial acoustic response was found to be proportional to the square of the tangential mass-flow rate used to generate swirl. When the tangential injection valve was closed, the mass-flow rate through the nozzle increased, resulting in an increase of the downstream acoustic pressure. This increase in signal was compared to the prediction of an empirical quasi-steady model, constructed from steady-state flow measurements. As the opening time of the valve was varied, the signal due to swirl evacuation showed an initial overshoot with respect to quasi-steady behavior, after which it gradually decayed to quasi-steady behavior for tangential injection times long compared to the convection time in the pipe upstream of the nozzle. This demonstrates that the acoustic signal can be used to obtain quantitative information concerning the time dependence of the swirl in the system. This could be useful for understanding the dynamics of flow in engines with swirl-stabilized combustion.

Item URL in elib:https://elib.dlr.de/143473/
Document Type:Article
Title:Swirl–nozzle interaction experiment: quasi-steady model-based analysis
Authors:
AuthorsInstitution or Email of AuthorsAuthor's ORCID iDORCID Put Code
Hirschberg, LionelUNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Bake, FriedrichUNSPECIFIEDhttps://orcid.org/0000-0002-3235-428XUNSPECIFIED
Knobloch, KarstenUNSPECIFIEDhttps://orcid.org/0000-0002-3424-0809UNSPECIFIED
Rudolphi, A.DLR, Institut für AntriebstechnikUNSPECIFIEDUNSPECIFIED
Kruck, SebastianUNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Klose, OliverUNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Hulshoff, Steven J.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Date:27 July 2021
Journal or Publication Title:Experiments in Fluids
Refereed publication:Yes
Open Access:Yes
Gold Open Access:No
In SCOPUS:Yes
In ISI Web of Science:Yes
Volume:62
DOI:10.1007/s00348-021-03271-y
Page Range:pp. 1-16
Publisher:Springer Nature
ISSN:0723-4864
Status:Published
Keywords:Indirect Combustion Noise, Swirl-Nozzle-Interaction, Core Noise
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Aeronautics
HGF - Program Themes:Clean Propulsion
DLR - Research area:Aeronautics
DLR - Program:L CP - Clean Propulsion
DLR - Research theme (Project):L - Components and Emissions
Location: Berlin-Charlottenburg
Institutes and Institutions:Institute of Propulsion Technology > Engine Acoustic
Deposited By: Bake, Dr.-Ing. Friedrich
Deposited On:19 Aug 2021 07:52
Last Modified:12 May 2023 13:06

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