Parallel numerical simulation of subsonic cavity noise

A parallel, multiblock, high-order accurate code has been developed for cavity noise prediction. An implicit, second-order time accurate, dual time-stepping algorithm that has shown promise in viscous aeroacoustic simulations has been implemented for the long time integration. The accuracy of the solution obtained with this method is comparable to typical explicit computational aeroacoustic algorithms, but eliminates the stringent time step requirement due to numerical stability for such schemes. Inner fictitious subit-erations are performed with a four-stage Runge-Kutta method, with the implementation of multigrid and local time stepping to accelerate convergence. The flow field over a two-dimensional cavity of length-to-depth ratio L/D = 4 has been simulated in the subsonic flow regime. The unsteady characteristics of the cavity flow and the mechanisms for cavity noise generation are discussed, and the effects of varying incoming boundary layer thickness on pressure fluctuations are examined.