In recent years, jet noise modeling research has primarily followed two different paths: the acoustic analogy approach and Large Eddy Simulation (LES). However, these approaches are, respectively, too restrictive and too expensive for realistic engineering applications. The main objective of the innovative research proposed by Thaerocomp Technical Corporation (TTC) is to develop predictive computational models and a software tool for large-scale turbulence noise in high-speed jets, with fidelity and computational expense suited for engineering applications. This supports a broader objective to develop new concepts for jet noise suppression based on modification and control of large-scale turbulence. The capability of relatively coarse unsteady simulations will be assessed with a focus on the ability to capture, with sufficient accuracy, the relevant features of the large-scale turbulence noise sources controlling the spectral peak at aft angles. The effect of nozzle design modifications on those sources and, hence, noise reduction could then be screened for highly three-dimensional designs such as lobed nozzles. These assessments will be based on comparisons with far field sound, as well as near-field pressure signatures of large-scale turbulence structures, constituting the source sound. Achieving this objective will establish TTC LES methodology as a practical engineering tool addressing peak-frequency, aft-angle noise radiation from large-scale turbulence. This complements the TTC RANS-based methodology for fine-scale turbulence noise developed under Phase I.
Keywords: Large Scale Noise, Fine Scale Noise, Shock-Assisted Noise, Large Eddy Simulation, Reynolds-Averaged Navier-Stokes Equations (Rans), Wave-Packet Analys
