Jet noise prediction using a sweeping based turbulence generation process

Anthony Lafitte , Estelle Laurendeau , Thomas Le Garrec , Christophe Bailly (1)

1 LMFA - Laboratoire de Mecanique des Fluides et d'Acoustique

A predictive tool of the noise generated by jet pumps, developed by Liebherr Aerospace for aircraft air conditioning systems application, is introduced in this paper. The model is simplified to the geometry of a confined subsonic jet. Starting from a steady RANS computation, a turbulent velocity field is built from a stochastic method to compute acoustic sources to be injected in Euler equations to model the near-field acoustic propagation. For CPU cost reductions, the far-field radiation is recovered using an acoustic analogy. In one hand, a new combined approach based on the sweeping hypothesis to generate isotropic turbulent fields is introduced. This model noticeably allows a satisfying modeling of the velocity correlation functions and more generally of the decorrelation process of the turbulent field. It also takes correctly into account the convection effects of the turbulent structures in the shear layer and has the advantage of being energy preserving [Lafitte et al., AIAA 2011-2088]. On the other hand, the coupling between this model and Onera’s Euler solver sAbrinA.v0 is tested on a subsonic free jet with a nozzle diameter D=80 mm at Mach number 0.72. Numerical spectra in the far-field are compared to experimental data available at the Onera.

Mots clés: Aeroacoustics; CAA; Stochastic method

Domaines: Acoustique [physics.class-ph]

Anthony Lafitte, Estelle Laurendeau, Thomas Le Garrec, Christophe Bailly. Jet noise prediction using a sweeping based turbulence generation process. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00810778⟩