Internal Noise Prediction within Aircraft Cabin

摘要

For about two decades, Structural Dynamics and Coupled Systems Department of ONERA has developed, validated and applied different methods for modeling and predicting internal and external noise of complex structures in the low (LF), medium (MF) and high (HF) frequency ranges. These activities were initialized for sound radiated from submarine structures and then applied to aeronautic and space structures as helicopters, planes and launchers, for internal noise prediction. For the LF and MF domains, these methods are based on Finite Element modeling for both structures and internal fluids and on the integral method for unbounded external fluids while for the HF domain, they are based on Statistical Energy Analysis (SEA). For the LF range, the classical modal approach is used for both structures and internal fluids. The coupling is then performed on the fluid-structure common interface. For the MF range, a specific method called Onera-MF method has been developed. This method uses a direct approach for the coupling between internal fluids and structures and it was implemented initially in an in-house version of ADINA code. Now it is implemented around Nastran code. For the HF range, the usual SEA method has been reformulated in order to take into account the coupling of external and internal heavy fluids with a structure. A ONERA code has been developed. A lot of validations and applications of the methods and associated codes were performed by numerous comparisons between theory and measurements.