Numerical and Physical Modeling of the Response of Resonator Liners to Intense Sound and High Speed Grazing Flow

An aeroacoustic computational code based upon a numerical solution of the full Navier-Stokes equations will be developed to provide a deep understanding of the physical behavior of resonator liners exposed to intense sound and boundary-layer grazing flow. The code computes the entire flow and acoustic field inside the flow duct. The user has the option to choose the flow Mach number, boundary-layer thickness, duct mode of incoming sound, frequency and SPL. For broadband sound, the user has the option to specify an incident noise spectrum. The code is designed to operate at both standard temperatures and very high temperatures. A semi-empirical three-dimensional resonator liner impedance code will developed for resonators also exposed to intense sound and boundary-layer grazing flow. The liner empirical parameters will be calibrated with NASA furnished resonator test data. Because of its simplicity, it can be used to provide realistic liner geometries for sound propagation codes that are used in both NASA and industry to determine optimum wall impedances to control excessive sound generated in jet engines and other flow duct environments.