Direct simulation of noise radiated by a mixing layer

A Large Eddy Simulation code (ALESIA for Appropriate Large Eddy Simulation for Aeroacoustics) was developed to compute the noise radiated by vortex pairing in a 2-D mixing layer. The code uses numerical techniques specific to Computational AeroAcoustics (CAA) in order to obtain the compressible field with high precision. We show that it is possible to determine directly the acoustic radiation, and that vortex pairing noise corresponds to a rotating quadrupole source. (C) 1999 Academie des sciences/Editions scientifiques et medicales Elsevier SAS.