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A computationally e¢ cient Ffowcs Williams-Hawkings acoustic analogy model has been incorporated in a modern CFD code. This methodology is based on the fact that the aerodynamic noise prediction can be performed in parallel with the aerodynamic computation. Near-…eld aerodynamics have been computed using unsteady Navier-Stokes equations with DES turbulence modeling. The sound propagation in far…eld is solved based on a e¢ cient implementation of the Farassat' s formulation 1A of the Ffowcs Williams-Hawkings equation, which assumes the propagation of sound waves in a medium at rest. Two complex three-dimensional cases, which look at the noise produced by the turbulent ‡ow over the tandem cylinders and an idealized side view mirror respectively, are presented to validate the new implementation.

SummaryA three-dimensional time-conservative finite-volume method is employed for the numerical analysis of the compressible flow and sound generation of an open rectangular cavity with a length-to-depth (L/D) ratio of 5 and a width-to-depth (W/D) ratio of 1. A Mach number of 0.85 and a Reynolds number of 6.8 million based on the cavity length are used as flow conditions. The large-eddy simulation (LES) technique is used in order to predict the turbulent flow field and the near-field cavity noise directly. Numerical results are compared with experimental data and results of high-order numerical schemes for sound pressure level (SPL) along the cavity floor. The computed near-field results using the present second-order scheme show high accuracy and high resolution comparable to those of high-order numerical schemes.