Lighthill's acoustic analogy is replaced by a theoretical model more representative of the true flow and the turbulence fluctuations within it. In this model the problem is divided into an outer region and an inner region which includes the turbulent flow and its convection. Pressure fluctuations in the inner region are suitably matched with those in the outer. Two important results are obtained. First, the generation of high-frequency components is not controlled by the gradients of mean velocity and temperature within the flow and, second, within a given frequency band of the far-field radiation, only certain regions of the turbulent flow contribute to that radiated sound.
|Original language||English (US)|
|Number of pages||37|
|State||Published - Jan 1 1975|
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