Ahmed, S.R. and Yin, J.P. and Dobrzynski, W. (1997) Effect of non-uniform rotation on acoustics and aerodynamics of propellers. In: Proceedings 5th International Congress on Sound and Vibration 1997, Vol. II, pp. 607-614. 5th International Congress on Sound and Vibration, University of Adelaide, South Australia, 15.-18.12.1997..
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This numerical study investigates the influence of non-uniform rotation on the aerodynamics and acoustics of multi-blade propellers.Non-uniform rotational motion is inherent to piston engine driven propellers. the effect of rotational speed non-uniformity is the generation of excess harmonic noise due to unsteady aerodynamic blade-loading. In case of mismatch between periodicity of non-uniformity and the basic blade passing frequency, additional harmonics are generated due to the complex blade kinematics. For a periodicity coincidence the effects are masked due to overlapping of the frequencies. The level of such extra harmonics may be high enough to dominate the overall A-weighted noise level. Propeller noise radiation for non-uniform rotation is no longer omnidirectional along azimuth and exhibits also a different characteristic in the polar direction.
|Document Type:||Conference or Workshop Item (Paper)|
|Title:||Effect of non-uniform rotation on acoustics and aerodynamics of propellers.|
|Journal or Publication Title:||Proceedings 5th International Congress on Sound and Vibration 1997|
|Page Range:||pp. 607-614|
|Keywords:||Unsteady panel method, aerodynamics of propellers, pressure time history, acoustic spectrum|
|Event Title:||5th International Congress on Sound and Vibration, University of Adelaide, South Australia, 15.-18.12.1997.|
|HGF - Research field:||UNSPECIFIED|
|HGF - Program:||Aeronautics|
|HGF - Program Themes:||other|
|DLR - Research area:||UNSPECIFIED|
|DLR - Program:||L ST - Starrflüglertechnologien|
|DLR - Research theme (Project):||L - Quiet Air Traffic (old)|
|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 10:06|
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