Accession Number : ADA174976
Title : DFVLR/FAA (Deutsche Forschungs-und Versuchsanstalt fuer Luft und Raumfahrt/Federal Aviation Administration) Propeller Noise Tests in the German- Dutch Wind Tunnel DNW
Descriptive Note : Executive data rept.
Corporate Author : DEUTSCHE FORSCHUNGS- UND VERSUCHSANSTALT FUER LUFT- UND RAUMFAHRT E V BRUNSWICK (GERMANY F R)
Personal Author(s) : Dobrzynski, Werner M ; Heller, Hanno H ; Powers, John O ; Densmore, James E
Report Date : Jan 1986
Pagination or Media Count : 164
Abstract : A joint effort to develop high quality propeller acoustics data, which could be used by manufacturers for acoustic design purposes, and by researchers to validate established or newly developed theoretical noise prediction methods. Specifically, the program addressed propeller Mach number and disc plane attitude effects as related to noise certification test and evaluation procedures. Changes in Mach number, as they affect acoustic data adjustments, were explored through independent variation of tunnel flow velocity, propeller rotational speed and ambient air temperature. The tests on the effect of in flow angle on propeller noise also incorporated the influence of a typical engine nacelle on the flow field and, hence, on the propeller noise. In this report, acoustic and operational data acquisition and reduction procedures are described. Only a selection of typical test results is presented, in order to illustrate the acoustic analysis techniques.
Descriptors : *PROPELLER NOISE , *AERIAL PROPELLERS , *AIRCRAFT NOISE , EXPERIMENTAL DESIGN , THEORY , ATMOSPHERIC TEMPERATURE , TUNNELS , VARIATIONS , FLOW FIELDS , FLOW RATE , MATHEMATICAL PREDICTION , WIND TUNNEL TESTS , DATA ACQUISITION , ACOUSTICS , FLOW , NOISE , MACH NUMBER , ROTATION , SOUND ANALYZERS , ENGINE NACELLES , PREDICTIONS , METHODOLOGY , VELOCITY , ANGLES
Subject Categories : Aircraft
Distribution Statement : APPROVED FOR PUBLIC RELEASE