Characterization of equivalent acoustic sources to reproduce the acoustic field generated by engines on an aircraft fuselage

Abstract

This work presents a general procedure to characterize equivalent acoustic sources to reproduce the sound pressure field generated by the engines on an aircraft fuselage. The procedure would allow to set up ground experimental tests on aircraft components, by means of distributed loudspeakers, to obtain their vibro-acoustic performances as if they were tested in flight conditions.A FEM model of an aircraft fuselage mock-up was built up, comprising the structure, the internal acoustic cavities and the external air. The sound pressure field generated by the engines was considered as the reference solution, whereas an equivalent sound field, produced by distributed monopole sources surrounding the structure, was obtained by leveraging on the proposed Multi-Disciplinary Optimization (MDO) procedure.The MDO procedure was based on the mutual interaction between the commercial codes Siemens NX, for the CAE/FEM simulations, and Noesis Optimus, for the optimization framework.