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Microphone-Array Measurements in European Transonic Wind Tunnel at Flight Reynolds Numbers

Ahlefeldt, Thomas (2017) Microphone-Array Measurements in European Transonic Wind Tunnel at Flight Reynolds Numbers. AIAA Journal, 55 (1), pp. 36-48. American Institute of Aeronautics and Astronautics (AIAA). DOI: 10.2514/1.J055262 ISSN 0001-1452

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Official URL: http://arc.aiaa.org/doi/full/10.2514/1.J055262

Abstract

This paper presents an experimental investigation of small-scale model airframe noise at various Reynolds numbers up to the real-flight case. The study consists of data acquired with a microphone array in the European Transonic Windtunnel (ETW). The advantage of the ETW is to enable testing simultaneously at cryogenic temperatures and increased pressure levels, which extends the range of achievable Reynolds numbers up to those pertaining to full-scale flight conditions. At the German Aerospace Center (DLR), the microphone-array measurement technique has been further developed to perform measurements under combined cryogenic and pressurized conditions. For this purpose, a microphone-array consisting of 96 microphones was designed and constructed. In this paper, aeroacoustic results are presented for various Reynolds numbers up to the real-flight case on an Airbus K3DY half-model of scale 1:13.6. The results showed significant Reynolds number and Mach number dependency for various sources. Of particular note are various dominant sources appearing on the flap at real-flight Reynolds numbers. To the authors knowledge, this is the first time that airframe noise data for a small-scale model have been acquired at real-flight Reynolds numbers.

Item URL in elib:https://elib.dlr.de/104715/
Document Type:Article
Additional Information:Publication Date (online): October 03, 2016
Title:Microphone-Array Measurements in European Transonic Wind Tunnel at Flight Reynolds Numbers
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Ahlefeldt, Thomasthomas.ahlefeldt (at) dlr.deUNSPECIFIED
Date:January 2017
Journal or Publication Title:AIAA Journal
Refereed publication:Yes
Open Access:Yes
Gold Open Access:No
In SCOPUS:Yes
In ISI Web of Science:Yes
Volume:55
DOI :10.2514/1.J055262
Page Range:pp. 36-48
Editors:
EditorsEmail
UNSPECIFIEDARC
Publisher:American Institute of Aeronautics and Astronautics (AIAA)
ISSN:0001-1452
Status:Published
Keywords:aeroacoustics, microphone array, cryogenic pressurized wind tunnel, real-flight/full-scale Reynolds number, high-lift
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Aeronautics
HGF - Program Themes:fixed-wing aircraft
DLR - Research area:Aeronautics
DLR - Program:L AR - Aircraft Research
DLR - Research theme (Project):L - Simulation and Validation
Location: Göttingen
Institutes and Institutions:Institute for Aerodynamics and Flow Technology > Experimental Methods, GO
Deposited By: Bachmann, Barbara
Deposited On:04 Jan 2017 10:36
Last Modified:31 Jul 2019 20:01

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