Development of approach for air engine tonal noise estimation

Effective and fast method for the sound pressure calculation in the far field is developed. This technique allows us to compare quickly different configurations of the fan stage according to the sound pressure level in the far field. For modeling of the generation process are used CFD methods, Navier-Stokes equations. Disturbances transmission process is modeled by means of the wave equation, reduced geometrical model is used, effects due to the viscosity and non-uniform mean flow is not taken into account. For the disturbances description in the far field are added the radiation from all point sources composing exit section of the channel. The modal content analysis of the sound source is carried out. Features of the analytical flange-model for description of the sound transmission process are studied.