New correlation model for the cascade of turbulent pulsations as a noise source in jets

The mechanisms of noise generation by turbulent jets associated with a cascade of turbulent perturbations are considered from generation of primary eddies to their disintegration. A new correlation model proposed for describing these mechanisms is based on simulation of their generation as a random process with deterministic description of individual eddies. The model makes it possible to analyze available correlation models based on experimental modeling of the correlation function: monopoles, dipoles, or quadrupoles. The main difference between these models is both the different multipole structure of assumed sources and implicit ??hard?? and ??soft?? variants of source generation, as well as in the main variable for which the correlation function is developed. This approach is used for developing the correlation model of the noise generation mechanism related to oscillations of surface eddies. The jet noise inferred from the proposed model is well consistent with experimental data on circular jet noise.