Stochastic prediction of broadband shock-associated noise including propagation effects

Cyprien Henry , Christophe Bailly (1) , Guillaume Bodard

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

Noise reduction is a major concern for engine manufacturers like Snecma. During the cruise phase, Broadband Shock-Associated Noise (BBSAN) originating from the aft of civil engines has been identified as an important source of noise. Within this framework, Snecma wishes to improve its prediction capabilities of BBSAN. A statistical model which uses a RANS calculation for input is being developed. The model is applicable to both single-stream and dual-stream engines. BBSAN sources are located in the mixing layers between primary and secondary streams and between secondary and flight streams. When the acoustic waves propagate from the sources to the ambient medium, they are refracted by the mean flow gradients. This propagation effect is taken into account using a ray tracing approach. The final paper will present the acoustic results on a dual-stream configuration. It will include thorough comparisons with measurements on the same configuration to assess the validity of the model.

Mots clés: shock-cell noise; RANS; statistical model; ray tracing

Domaines: Acoustique [physics.class-ph]

Cyprien Henry, Christophe Bailly, Guillaume Bodard. Stochastic prediction of broadband shock-associated noise including propagation effects. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00810953⟩