Numerical Simulation of Sound Generation and Propagation in and outside a Cabin Air Intake

Abstract

Aerodynamic noise generated by the low Mach number flow in air cabin intake is investigated numerically. For analysis a realistic intake installed DLR's cabin test facility Do728, was chosen. Two independent approaches were used. First, the so called hybrid approach, based an incompressible simulation of the airflow in the intake and Lighthill aeroacoustical analogy was applied, which separates generation and propagation of sound. The flow field was calculated with open source code OpenFOAM and acoustical sources and sound waves propafation were computed with commercial program Virtual.Lab. Second, the flow and acoustical fiel were computed in a Computational Aero Acoustics calculation (CAA) with the Star-CCM* code. The latter simulates both the unsteady turbulent flow and the noise it generates. The results from both calculations were compared and discussed.