Publication Date:
2019-07-13
Description:
Coherence measurements between fluctuating pressure in the combustor of a YF-102 turbofan engine and far-field acoustic pressure were made. The results indicated that a coherent relationship between the combustor pressure and far-field existed only at frequencies below 250 Hz, with the peak occurring near 125 Hz. The coherence functions and the far-field spectra were used to compute the combustor-associated far-field noise in terms of spectra, directivity, and acoustic power, over a range of engine operating conditions. The acoustic results so measured were compared with results obtained by conventional methods, as well as with various semiempirical predictions schemes. Examination of the directivity patterns indicated a peak in the combustion noise near 120 deg (relative to the inlet axis).
Keywords:
AIRCRAFT PROPULSION AND POWER
Type:
NASA-TM-73748
,
E-9320
,
AIAA PAPER 77-1277
,
Aeroacoustics Conf.; Oct 03, 1977 - Oct 05, 1977; Atlanta
Format:
application/pdf
Permalink
