Broadband Shock-Associated Noise

The characteristics of shock-associated noise were described in Section 2.2 Harper-Bourne and Fisher (1974) proposed a simple model, consisting of phased sources at regular intervals to represent the turbulence/shock cell system interaction. They inferred that the interaction of the spatially co­herent turbulence with the quasi-periodic point sources would be necessary to produce the observed noise characteristics in the far field. Tam (1995a) stressed that any shock noise model must incorporate these features and points out that prior and later studies on sound generation by the interac­tion of random turbulence with a single shock wave do not represent the generation mechanism of broadband shock-associated noise. This section describes the broadband shock-associated noise generation mechanism as well as models to predict its radiated noise.