Optimization of Noise Control Treatments for Aircraft’s Sidewalls 2016-01-1850

In passenger aircraft the most important noise control treatment is the primary insulation attached to the fuselage. Next to its acoustic properties the primary insulation main purpose is the thermal insulation and the minimization of condensed water. In general it consists of fibrous materials like glass wool wrapped in a thin foil. Due to stringent flame, smoke and toxicity requirements the amount of available materials is limited. Furthermore the amount of material installed in aircraft per year is much smaller compared to needs in the automotive industry. Therefore the best lay-up of the available materials is needed in terms of acoustics.

This paper presents a tool for numerical optimization of the sound insulation package. To find an improved insulation the simulation tool is used in interaction with a measurement database. The databank is constructed from aircraft grade materials such as fibrous materials, foams, resistive screens and impervious heavy layers. The database includes as well materials new to the aircraft industry to check if the acoustic potential justifies a new material qualification. The tool enables as well the optimization for different frequency ranges as well as for single wall or double wall configurations depending on the fuselage section. Typical constraints are the overall thickness and the weight. Results will be illustrated for different optimization strategies