Continued Development of a Coupled LES/Stochastic Approach to Jet Noise Prediction

Turbulence modeling for jet noise prediction remains a challenge due to the wide range of temporal and spatial scales present in the jet. Smaller turbulent scales corresponding to higher-frequency jet noise content often reside in a critical range for human hearing. Resolving this content with LES or DNS requires a large amount of computational resources. With the goal of extending the high frequency content of LES jet noise predictions at a reduced cost, we employ a coupled LES/stochastic method, wherein large flow structures are solved via very large eddy simulations (VLES), while the smaller-scale flow structures are modeled via synthetic turbulence. We show the feasibility of such a coupled approach with a Fourier-based stochastic method, and we present progress toward developing a synthetic-eddy-based method for the supplemented small-scale turbulence. Comparisons between the current approach and pure LES show that predicting additional higher frequency content in a more cost-effective approach is more efficient than simply increasing the grid resolution in the LES framework.