Présidents de session
JISFA 3 / Aircraft Interior Noise
- Frank Simon (ONERA)
The presentation will introduce Main Gear box noise generation mechanism and transfer path to helicopter cabins.
From this introduction, various noise control solutions dedicated to this typical issue in helicopter cabins will be presented, providing an overview of typical treatments used to improve comfort of passengers.
The internal noise inside an aircraft induced by a turbulent flow results from a coupling between aerodynamics and vibroacoustics through the turbulent wall pressure (TWP). By applying instationary forces on a structure, this pressure initiates a vibratory motion which will generate noise by acoustic radiation. Modeling these phenomena is equivalent to solving a filtering problem. The input is...
Engine noise plays a variable role in cabin comfort, depending on the engine type. This presentation will focus on engine-to-cabin airborne transmission, prediction process and validation tests.
Duct acoustic network modelling is commonly carried out using the transfer matrix formalism which is limited to the low frequency range. The aim of this work is to extend it to higher frequencies by taking into account the multi-mode acoustic propagation. The first step is to compute, via finite element discretisation (FEM), the multi-port multi-modal scattering matrix of each element. The...
The identification and ranking of sound sources contributing to aircraft interior noise is not an easy task, due to the complexity of the involved physical phenomena. The turbulent boundary layer developed on the fuselage is recognized as one of the dominant sources, but there is also engine noise, airframe noise and noise from the air-conditioning system. When implementing flight tests,...
