A Versatile Implementation of Acoustic Analogy Based Noise Prediction Method in a General-Purpose CFD Code

Abstract

This paper is concerned with incorporation of a noise prediction method based on acoustic analogy in a generalpurpose computational fluid dynamics (CFD) code based on finite-volume Navier-Stokes solver. Near-field aerodynamics can be obtained by solving, when appropriate, unsteady inviscid (Euler) equations, Navier-Stokes equations, averaged or filtered Navier-Stokes equations. Propagation of sound waves is computed using the time-domain integral formulation of Ffowcs-Williams and Hawkings. Both the flow solver and the acoustics module are fully parallelized. A forward time-projection technique is employed to effect the time-lag between emission and reception times. Some implementational issues impacting the usability are discussed, such as user-interfaces, data management, and postprocessing. Also discussed are some diagnostic tools useful to extract quantitative information on the local contributions from different parts of the emission surfaces. Several examples are presented, including simple two-dimensional cases to a more complex three-dimensional one.