Single and Multivariate Statistics of Jet-Induced Pressure Fluctuations over an Infinite Plate

Abstract

Motivated by the problem of the installation effects of modern turbofan engines, we experimentally investigated the interaction between a compressible subsonic jet and a tangential flat plate. Measurements of wall pressure fluctuations were performed in a semi-anechoic environment addressing the effect of several governing parameters, such as the stream-wise and span-wise location, the jet Mach number and the radial distance of the plate surface from the jet axis. The statistical properties of the wall pressure signals were analyzed in terms of both power spectra and cross-correlations, with the latter providing the estimation of the phase speed. The analysis is also carried out in the time-frequency domain through the application of the wavelet transform to further characterize the dynamics of the wall pressure signatures.

Keywords

• jet noise
• wall pressure fluctuations
• wavelet