Modeling the effects of wind tunnel wall absorption on the acoustic radiation characteristics of propellersFinite element theory is used to calculate the acoustic field of a propeller in a soft walled circular wind tunnel and to compare the radiation patterns to the same propeller in free space. Parametric solutions are present for a 'Gutin' propeller for a variety of flow Mach numbers, admittance values at the wall, microphone position locations, and propeller to duct radius ratios. Wind tunnel boundary layer is not included in this analysis. For wall admittance nearly equal to the characteristic value of free space, the free field and ducted propeller models agree in pressure level and directionality. In addition, the need for experimentally mapping the acoustic field is discussed.
Document ID
19870030717
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Baumeister, K. J. (NASA Lewis Research Center Cleveland, OH, United States)
Eversman, W. (Missouri-Rolla, University Rolla, United States)