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Azimuthal Noise Characteristics of Contra-Rotating Propellers: Results of a Wind Tunnel Model Test.

Gehlhar, B. and Dobrzynski, W. (1990) Azimuthal Noise Characteristics of Contra-Rotating Propellers: Results of a Wind Tunnel Model Test. Inter-Noise '90, 13-15 August 1990, Göteborg.

Full text not available from this repository.

Abstract

Compared to conventional turbofan engines, advanced high speed coaxial/contra-rotating ("CR") propellers promise significant fuel savings. Their noise characteristics, however, differ from those of singe-rotating ("SR") propellers as a consequence of the unavoidable acoustic interaction effects; additional noise is generated by aerodynamic interactions. In the context of an acoustic research program to support the development of future CR-propfans, pilot-type aerodynamic wind tunnel tests on contrarotating model-scale propellers (diameter 0,27 m)were conducted. It was found that, compared to SR-propellers, the noise radiated from CR-propellers exhibits the following specific characteristics: o increased sound pressure levels at higher frequencies, o pronounced azimuthal sound pressure level directivity, o two maxima in the polar directivities of both the high-frequency ha rmonic and the A-weighted levels, o a lower gradient of A-weighted sound pressure levels versus Mach number.

Document Type:Conference or Workshop Item (Paper)
Additional Information: LIDO-Berichtsjahr=1990, pages=4,
Title:Azimuthal Noise Characteristics of Contra-Rotating Propellers: Results of a Wind Tunnel Model Test.
Authors:
AuthorsInstitution or Email of Authors
Gehlhar, B.UNSPECIFIED
Dobrzynski, W.UNSPECIFIED
Date:1990
Page Range:pp. 471-475
Status:Published
Keywords:Propeller Noise, Counter Rotating Propeller Noise
Event Title:Inter-Noise '90, 13-15 August 1990, Göteborg
HGF - Research field:UNSPECIFIED
HGF - Program:other
HGF - Program Themes:other
DLR - Research area:UNSPECIFIED
DLR - Program:no assignment
DLR - Research theme (Project):L - Turbine Technologies
Location: Köln-Porz , Braunschweig , Göttingen
Institutes and Institutions:Institute of Aerodynamics and Flow Technology > Institut für Entwurfsaerodynamik
Deposited By: elib DLR-Beauftragter
Deposited On:03 Apr 2006
Last Modified:27 Apr 2009 10:04

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