Publication Date:
2019-07-13
Description:
A study of Propfan far-field noise is carried out based on geometrical acoustics theory. The analysis traces the acoustic rays and ray tube areas carrying the acoustic disturbances to the far-field. Sound attenuation due to nonlinear steepening, atmospheric absorption and turbulence scattering are also investigated. A comparison of our prediction methodology with experimental acoustics measurement shows good agreement. Geometrical decay and atmospheric absorption are identified as the primary noise attenuating mechanisms. Nonlinear effects are negligible. It is determined that the acoustic footprints of advanced propellers are dominated by caustics. Details of the formation of these caustics may provide a basis for future noise minimization efforts.
Keywords:
ACOUSTICS
Type:
AIAA PAPER 93-0602
,
; 13 p.|AIAA, Aerospace Sciences Meeting and Exhibit; Jan 11, 1993 - Jan 14, 1993; Reno, NV; United States
Format:
text