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Examination of the Influence of Flight Altitude and Speed on the Efimtsov Model Parameters

Haxter, Stefan and Spehr, Carsten (2013) Examination of the Influence of Flight Altitude and Speed on the Efimtsov Model Parameters. In: 19th AIAA/CEAS Aeroacoustics Conference (AIAA 2), pp. 1-27. American Institute of Aeronautics and Astronautics Inc.. 19th AIAA/CEAS Aeroacoustics Conference (34th AIAA Aeroacoustics Conference), 27. - 29. May 2013, Berlin, Germany. DOI: 10.2514/6.2013-2028 ISBN 978-162410213-4

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Official URL: https://doi.org/10.2514/6.2013-2028

Abstract

A flight test was conducted and the data was evaluated in order to investigate the influence of flight altitude and flight speed on the coherence length model by Efimtsov. An underestimation of the measured values by the model was found below a frequency of 1kHz. Above this frequency, the predicted values matched the measured values very well. The Efimtsov ansatz was found to be suitable for the description of coherence length, when the parameters are adapted. Three further analyses were performed: the flight speed was varied with constant altitude, the altitude was varied with constant flight speed, and both speed & altitude were varied together. No considerable variation was measured when the flight speed was varied separately. A small variation was determined at low frequency when the flight altitude was altered separately. When varying the parameters together, a distinct variation was found for the cases of highest speed and altitude. The applicability of the exponential coherence decay was analyzed. The absolute deviation was found to increase with lower frequency. The characteristic of the deviation was found to collapse in different regions with different scaling of the strouhal number.

Item URL in elib:https://elib.dlr.de/77817/
Document Type:Conference or Workshop Item (Speech)
Additional Information:DOI: 10.2514/6.2013-2028
Title:Examination of the Influence of Flight Altitude and Speed on the Efimtsov Model Parameters
Authors:
AuthorsInstitution or Email of AuthorsAuthor's ORCID iD
Haxter, Stefanstefan.haxter (at) dlr.dehttps://orcid.org/0000-0002-9232-2802
Spehr, Carstencarsten.spehr (at) dlr.dehttps://orcid.org/0000-0002-2744-3675
Date:24 May 2013
Journal or Publication Title:19th AIAA/CEAS Aeroacoustics Conference
Refereed publication:No
Open Access:Yes
Gold Open Access:No
In SCOPUS:Yes
In ISI Web of Science:No
DOI :10.2514/6.2013-2028
Page Range:pp. 1-27
Editors:
EditorsEmailEditor's ORCID iD
UNSPECIFIEDAIAAUNSPECIFIED
Publisher:American Institute of Aeronautics and Astronautics Inc.
Series Name:Conference Proceedings online
ISBN:978-162410213-4
Status:Published
Keywords:turbulent boundary layer, coherence length model,
Event Title:19th AIAA/CEAS Aeroacoustics Conference (34th AIAA Aeroacoustics Conference)
Event Location:Berlin, Germany
Event Type:international Conference
Event Dates:27. - 29. May 2013
Organizer:American Institute of Aeronautics and Astronautics
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Aeronautics
HGF - Program Themes:Aircraft Research (old)
DLR - Research area:Aeronautics
DLR - Program:L AR - Aircraft Research
DLR - Research theme (Project):L - Simulation & Validation (old)
Location: Göttingen
Institutes and Institutions:Institute for Aerodynamics and Flow Technology > Experimental Methods, GO
Deposited By: Micknaus, Ilka
Deposited On:22 Aug 2013 13:32
Last Modified:15 Jul 2020 11:36

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