Time-domain computation of broadband noise due to interaction of a rectilinear cascade of flat plates with inflow turbulence

In this paper, time-domain computational aeroacoustic (CAA) methods are developed to predict broadband noise generation and propagation by a rectilinear cascade of flat plates interacting with ingesting turbulent gust. Utilizing three-dimensional time-domain CAA model, the three-dimensional characteristics of inflow turbulence noise due to the turbulence-cascade interaction are investigated with an emphasis placed on the effects of wavenumber components of ingesting turbulence in the span-wise direction. Through the comparison of three-dimensional results with two-dimensional ones, the characteristics of sound pressure spectrums obtained from the three-dimensional results are revealed, which is mainly due to the different dispersion relations of acoustic waves in two- and three-dimensions. These differences between two- and three-dimensional results become more significant in the lower frequency components. In addition, some preliminary numerical results on the effects on the broadband noise of a rectilinear cascade of leaned or swept flat plates are illustrated, which can provide basic principle for the low-noise design of the stator in turbo-fan engines.