Contemporary Challenge of Connecting Turbulence Models with Time and Spectral Analytical Acoustic Sources

Contemporary Reynolds-averaged Navier-Stokes (RANS) based turbulence models provide Reynolds stresses, turbulent kinetic energy, dissipation, and a multitude of other variables via their particular closure. Recently, my students and myself have proposed both time-domain and spectral-domain sources of noise based on recent closed-form acoustic prediction equations. These noise source terms, which have recently been validated for turbulent jet flows and homogeneous turbulence, do not directly coincide with terms of RANS based turbulence models. In this talk, I identify sources that include fine-scale mixing noise, shock wave turbulence interaction, and large-scale coherent turbulent structures. These source terms are compared with one-equation, two-equation, and Reynolds stress based RANS models. We explain how these terms are approximated via RANS results and present the challenge of modifying RANS closures to directly find source terms.