A theoretical study of self soise generation in turbulent jets using one dimensional turbulence and Lighthill’s acoustic analogy

Kurzfassung

Modeling and simulation of turbulent jet noise is an ongoing numerical challenge relevant to noise pollution control. In the present study, the concept of a novel dimensionally reduced modeling approach based on the so-called one-dimensional turbulence model (ODT) is discussed. ODT aims to resolve source terms due to velocity and kinematic pressure variations in the acoustic near-field at all relevant scales, but only for a single physical coordinate. In the standalone formulation of the model, the physical coordinate taken as a notional line of sight that is pointing in radial cross-stream direction and advected downstream with the axial velocity of the jet while the microscales evolve. Thereby, turbulence is represented by a stochastically sampled sequence of discrete mapping events that punctuate the deterministic molecular diffusive advancement. It is discussed how an ensemble of small-scale resolving independent flow realizations can be used to estimate turbulent noise sources from a range of scales. The main objective is to present an approach for the prediction of broadband self-noise generated by a turbulent jet using ODT and Lighthill’s equation. Dedicated experimental measurements are conducted for verification and validation of the numerical modeling approach.